bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of polyethylene glycol on the properties of styrene‐butadiene rubber/organoclay nanocomposites filled with silica and carbon black
Authors: Kim Wook‐Soo , Paik Hyun‐Jong , Bae Jong‐Woo , Kim Wonho
Published: June 2011

Polyethyene glycol (PEG) is widely used as a dispersing agent and can also be used to prevent the adsorption of ingredients on the surface of silica. From the XRD results, PEG that was used as the dispersing agent on the SBR/organoclay compound filled with silica and carbon black (CB) was intercalated between the organoclay layer. Additionally, the interactions with the PEG differed depending on whether 3‐aminopropyltriethoxysilane (APTES) or N,N‐dimethyldodecylamine (DDA) were used as clay modifiers. When PEG was added, the Tg of the SBR/silica/APTES‐MMT compound increased through the formation of hydrogen bonds between the ether linkages of PEG and the hydroxyl groups of APTES. For the SBR/silica/DDA‐MMT compound with PEG, slippage occurred between the silicate, and DDA because of the alkyl chain of DDA. The SBR/silica/APTES‐MMT/CB compound with PEG exhibited the highest Tg value and the highest bound rubber content, with high modulus values at 100 and 300%. The SBR/silica/DDA‐MMT/CB compound had the best properties in terms of the wet skid resistance and the rolling resistance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Radiolytic synthesis of OH group functionalized fullerene structures and their biosensor application
Authors: Chung Da‐Jung , Seong Mi‐Kyeng , Choi Seong‐Ho
Published: June 2011

In this study, radiolytic functionalization of fullerene in methanol/1,2‐dichlorobenzene mixtures and its applications with respect to biosensor support materials were studied. To obtain supports for biosensors for electron transfer, fullerene was functionalized by γ‐irradiation in a methanol/1,2‐dichlorobenzene mixture solution. The hydroxyl group‐modified fullerene, F‐fullerene, was characterized by Fourier‐transform infrared, Raman spectroscopy, MALDI‐TOF mass spectroscopy, and elemental analysis. As a result, the main hydroxyl group was successfully introduced on the surface of fullerene. F‐fullerene was found to disperse well in water by ultrasonication. The results indicated that F‐fullerene is a good candidate for use in biological systems as a biosensor support material. A biosensor based on F‐fullerene was prepared by hand‐casting the mixture of tyrosinase, F‐fullerene, and 2% chitosan solution on an ITO electrode. Furthermore, the prepared biosensor was optimized pH and temperature. The prepared biosensor was then evaluated for its ability to analyze phenolic compounds contained in commercial red wines. The total phenolic concentration was determined to be in the range of 397–895 mg/L. From these results, the electron transfer ability of F‐fullerene was improved on an enzyme biosensor. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Rheological and topological characterizations of electron beam irradiation prepared long‐chain branched polylactic acid
Authors: Wang Yongbin , Yang Liang , Niu Yanhua , Wang Zhigang , Zhang Jun , Yu Fengyuan , Zhang Hongbin
Published: June 2011

In this study, a series of linear‐ and long‐chain branched polylactic acid (PLA) samples was prepared by electron beam irradiation without or with addition of a trifunctional monomer, trimethylolpropane triacrylate (TMPTA). The chain structures of the PLA samples were characterized by size‐exclusion chromatography coupled with a light scattering detector (SEC‐MALLS) and shear and extensional rheology. PLA tends to degrade while keeps linear structures with increasing irradiation dose and without addition of TMPTA, as evidenced by decreased molecular mass Mw and reductions of storage modulus G′ and the zero shear viscosity η0. Long‐chain branched PLA samples were successfully prepared with irradiation and addition of TMPTA, which shows prominent higher η0 and apparent flow activation energy, longer characteristic relaxation time τ, and pronounced strain‐hardening behaviors. With increasing amount of TMPTA, Mw dependences of η0 and the root mean square radius of gyration Rg obviously deviate from the scaling relation of linear PLA samples, which strongly indicates the increased long‐chain branching degree for the branched PLA samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation and mechanical and electrical properties of graphene nanosheets–poly(methyl methacrylate) nanocomposites via in situ suspension polymerization
Authors: Wang Jingchao , Hu Huating , Wang Xianbao , Xu Chunhui , Zhang Min , Shang Xiaopeng
Published: June 2011

Graphene nanosheets–poly(methyl methacrylate) (GNS–PMMA) nanocomposites were first prepared by in situ suspension polymerization and reduction of graphene oxide using hydrazine hydrate and ammonia. PMMA microspheres with a mean diameter of 2 μm are mainly covalently link to the surface of GNS. The obtained GNS–PMMA composites have not only high electrical conductivity but also enhanced mechanical properties and thermal stability at low loadings of graphene. Especially, the resulting nanocomposites were examined for electrorheological fluids, showing thin and dense chains of particles after application of an electric field. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of polyaniline/NiO nanocomposite
Authors: Shambharkar B. H. , Umare S. S.
Published: June 2011

Spherical nickel oxide (NiO) nanoparticles were prepared by using nickel chloride as precursor in the ethylene glycol as solvent and urea as precipitant. The X‐ray diffraction study showed that NiO has single‐phase cubic structure with average crystallite size of 35 nm. The prepared NiO nanoparticles were incorporated into polyaniline (PANI) matrix during in situ chemical oxidative polymerization of aniline with different molar ratios of aniline: NiO (12 : 1, 6 : 1, and 3 : 1) at 5°C using (NH4)2S2O8 as oxidant in aqueous solution of sodium dodecylbenzene sulfonic acid, as surfactant and dopant under N2 atmosphere. The synthesized composites have been characterized by means of X‐ray diffraction (XRD), thermogravimetric analysis, Fourier transform infrared (FTIR), scanning electron microscopy, TEM, and vibrating sample magnetometer for its structural, thermal, morphological, and magnetic investigation. The XRD and FTIR studies show that the NiO particles are in the composite. The room temperature conductivities of the synthesized PANI, PANI/NiO (12 : 1), (6 : 1), and (3 : 1) composites were found to be 3.26 × 10−4, 1.88 × 10−4, 1.5 × 10−4, and 4.61 × 10−4 S/cm, respectively. The coercivity (Hc) and remnant magnetization (Mr) of NiO, PANI/NiO NCs (12 : 1), (6 : 1), and (3 : 1) at 5 K was found to be 8.22 × 10−2, 6.31 × 10−2, 6.42 × 10−2, 6.27 × 10−2 T, and 6.64 × 10−3, 1.83 × 10−4, 3.07 × 10−4, and 3.98 × 10−4 emu/g, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Analysis of the global production location dynamics in the industrial wood pellet market: an MCDA approach
Authors: Smith T. Pieter , Junginger H. Martin
Published: June 2011

Industrial wood pellet demand and international trade have been growing rapidly, requiring producers to build new production facilities. The purpose of this paper is to illustrate the trade‐offs of different wood pellet production locations across the world within the next ten years and to improve the quality and viability of future wood pellet production location and supply chain decisions. To this end, a multi‐criteria decision analysis (MCDA) was performed. This approach enabled assimilation and synthesis of both qualitative and qualitative data of a comprehensive set of regions in which lies its originality.

The following characteristics were indicated and assessed: feedstock (availability, competition, and pricing), investment climate, electricity prices, market potential, and logistics. Analysis of various scenarios resulted in a preference for Northern American, Austrian, Belgian, and German regions based either on superior feedstock pricing or logistic position, complemented by a stable investment climate. However, a scenario of high demand of ocean freight quickly diminished the performance of Western Canada and the USA, Brazil, and Chile. Austria, Belgium, and Germany remained most volatile for feedstock shortages. Overall, Austria, Estonia, Czech Republic, and Sweden seem more robust to perform well in different scenarios, which may prove crucial to limit risk exposure in an emerging market. Some more remote regions with huge feedstock potential (e.g. Russia) depend on the investment climate and logistical feasibility of these regions. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Sources of corn for ethanol production in the United States: a decomposition analysis of the empirical data
Authors: Oladosu Gbadebo , Kline Keith , Uria‐Martinez Rocio , Eaton Laurence
Published: June 2011

The use of corn for ethanol production in the United States quintupled between 2001 and 2009, generating concerns that this could lead to the conversion of forests and grasslands around the globe, known as indirect land‐use change (iLUC). Estimates of iLUC and related ‘food versus fuel’ concerns rest on the assumption that the corn used for ethanol production in the United States would come primarily from displacing corn exports and land previously used for other crops. A number of modeling efforts based on these assumptions have projected significant iLUC from the increases in the use of corn for ethanol production. The current study tests the veracity of these assumptions through a systematic decomposition analysis of the empirical data from 2001 to 2009. The logarithmic mean divisia index decomposition method (Type I) was used to estimate contributions of different factors to meeting the corn demand for ethanol production. Results show that about 79% of the change in corn used for ethanol production can be attributed to changes in the distribution of domestic corn consumption among different uses. Increases in the domestic consumption share of corn supply contributed only about 5%. The remaining contributions were 19% from added corn production, and –2% from stock changes. Yield change accounted for about two‐thirds of the contributions from production changes. Thus, the results of this study provide little support for large land‐use changes or diversion of corn exports because of ethanol production in the United States during the past decade. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Passagenwerk 1850. Bild und Zahl in den physiologischen Zeitexperimenten von Hermann von Helmholtz
Authors: Schmidgen Henning
Published: June 2011

Arcades Project 1850. Image and Number in the Physiological Time Experiments of Hermann von Helmholtz. In January 1850, Hermann von Helmholtz (1821–1894) published a short report about his measurements concerning the propagation speed of “stimulations” in the living nerve. Historians of science such as Frederic Holmes and Kathryn Olesko have reconstructed the “investigative pathway” that led Helmholtz from his initial work on muscle action to the striking study of nervous time. Against the background of new archival findings, this paper argues that Helmholtz's investigative pathway also constituted a “semiotic pathway,” i. e. an arcade of signs that would capture and transmit his findings in appropriate ways. Drawing in particular on the curve recordings and the corresponding written explanations he sent to the Paris Academy of Science in September 1851, the paper shows that Helmholtz's graphical recordings were not meant as measurements. From the start, Helmholtz had carried out his time measurements by using an electromagnetic timing method suggested by the French physicist Claude Pouillet (1791–1868). In his 1850 report, Helmholtz had failed, however, to explain the physiological application of this method, even though his colleague and friend, Emil du Bois‐Reymond (1818–1896) had revised the report when translating it into French. In this situation, Helmholtz's curves served to illustrate the basic procedure of his previous experiments. In other words, they were indeed ‘images of precision’ (Holmes and Olesko) but not precise images.
Nerve root to lumbar disc relationships at the intervertebral foramen from a surgical viewpoint: An anatomical study
Authors: Arslan Mehmet , Cömert Ayhan , Açar Hali̇l İbrahi̇m , Özdemi̇r Mevci̇ , Elhan Alai̇tti̇n , Tekdemi̇r İbrahi̇m , Tubbs R. Shane , Uğur Hasan Çağlar
Published: June 2011

The objective of this study was to analyze relationship of the intervertebral disc to the nerve root in the intervertebral foramen. Fourteen formalin‐fixed cadavers were studied and measurements were performed. At the medial line of the neural foramen, the disc‐root distance gradually increased from L1‐L2 to L5‐S1. The shortest distance between the disc to nerve root was L1‐L2 (mean, 8.2 mm) and the greatest distance was found at L3‐L4 (mean, 10.5 mm). In the mid‐foramen, the disc‐root distance decreased from L1‐2 to L5‐S1. The shortest distance from the disc to nerve root was found at L5‐S1 (mean, 0.4 mm); and the greatest distance, at L1‐L2 (mean, 3.8 mm). For the lateral line, the distance between an intersection point between the medial edge of the nerve root and the superior edge of the disc and lateral line of the foramen consistently increased from L1‐L2 to L5‐S1. The shortest distance from nerve root to the lateral border of the foramen, at the point where the nerve root crosses disc was at level L1‐L2 (mean, 2.6 mm), the greatest distance, L5‐S1 (mean, 8.8 mm). The width of the foramina progressively increased in a craniocaudal direction (mean, 8.3–17.8 mm from L1‐2 to L5‐S1, respectively). The mean height of the foramina was more or less the same for disc levels (range, 19.3–21.5). The results showed that nerve roots at lower levels traveled closer to the midline of the foramen. This morphometric information may be helpful in minimizing the incidence of injury to the lumbar nerve root during foraminal and extraforaminal approaches. Clin. Anat. 25:218–223, 2012. © 2011 Wiley‐Liss, Inc.
Structural Characterization of Phosphorus‐Based Networks and Clusters: 31P MAS NMR Spectroscopy and Magnetic Shielding Calculations on Hittorf’s Phosphorus
Authors: Wiegand Thomas , Eckert Hellmut , Grimme Stefan , Hoppe Diana , Ruck Michael
Published: June 2011

The 31P MAS NMR spectrum of Hittorf’s phosphorus has been measured and assigned to the 21 crystallographically distinct phosphorus atoms based on two‐dimensional dipolar correlation spectroscopies. Application of such 2D techniques to phosphorus‐based networks is particularly challenging owing to the wide chemical shift dispersions, rapid irreversible decay of transverse magnetization, and extremely slow spin‐lattice relaxation in these systems. Nevertheless, a complete assignment was possible by using the combination of correlated spectroscopy (COSY) and radiofrequency‐driven dipolar recoupling (RFDR). The assignment is supported further by DFT‐based ab initio chemical shift calculations using a cluster‐model approach, which gives good agreement between experimental and calculated chemical shift values. The 31P chemical shifts appear to be strongly correlated with the average PP bond lengths within the P(P1/3)3 coordination environments, whereas no clear dependence on average P‐P‐P bond angles can be detected.

Calculations of localized Kohn–Sham orbitals reveal that this bond‐length dependence is reflected in energy variations in the corresponding localized p‐p‐σ orbitals influencing the paramagnetic deshielding contribution in Ramsey’s equation. In contrast, the contributions of the lone pairs to shielding differences are small and/or do not vary in a systematic manner for the different crystallographically distinct phosphorus sites. The combined spectroscopic and quantum chemical approach applied here and the increased theoretical understanding of 31P chemical shifts will facilitate the structural elucidation of other phosphorus‐based clusters and networks.
Stereoselective Conjugate Addition Reactions to Phenylglycinol‐Derived, Unsaturated Oxazolopiperidone Lactams
Authors: Amat Mercedes , Pérez Maria , Bosch Joan
Published: June 2011

Phenylglycinol‐derived, unsaturated oxazolopiperidone lactams are extremely useful building blocks that undergo stereoselective conjugate addition reactions with organocuprates, enolates, and sulfur‐stabilized anions, allowing the stereocontrolled introduction of substituents at the piperidine 4‐position. The factors governing the exo‐ or endo‐facial selectivity are discussed. The methodology can be used for the preparation of a variety of enantiopure piperidines, including pharmaceuticals, alkaloids precursors, piperidine‐fused derivatives, as well as complex piperidine‐containing natural products.
A Label‐Free Gold‐Nanoparticle‐Based SERS Assay for Direct Cyanide Detection at the Parts‐per‐Trillion Level
Authors: Senapati Dulal , Dasary Samuel S. R. , Singh Anant K. , Senapati Tapas , Yu Hongtao , Ray Paresh C.
Published: June 2011

Cyanide is an extremely toxic lethal poison known to humankind. Developing rapid, highly sensitive, and selective detection of cyanide from water samples is extremely essential for human life safety. Driven by the need, here we report a gold‐nanoparticle‐based label‐free surface‐enhanced Raman spectroscopy (SERS) system for highly toxic cyanide ion recognition in parts‐per‐trillion level and to examine gold‐nanoparticle–cyanide interaction. We have shown that the SERS assay can be used to probe the gold nanoparticle dissociation process in the presence of cyanide ions. Our experimental data indicates that gold‐nanoparticle‐based SERS can detect cyanide from a water sample at the 110 ppt level with excellent discrimination against other common anions and cations. The results also show that the SERS probe can be used to detect cyanide from environmental samples.
ChemInform Abstract: Preparation of Novel 2,3,8‐Trisubstituted Pyrido[3,4‐b]pyrazines and Pyrido[2,3‐b]pyrazines.
Authors: Antoine Maud , Czech Michael , Gerlach Matthias , Guenther Eckhard , Schuster Tilmann , Marchand Pascal
Published: June 2011

An efficient synthetic approach to the preparation of the title compounds (VIII) and (XVI) is developed.
Ozon macht Pollen schärfer
Authors: Feil Sylvia
Published: June 2011

Wirbeln Gräser‐ und Birkenpollen in die Luft auf, sinken sie chemisch verändert wieder herab. Ähnlich wie im Meer jede Oberfläche besiedelt wird, bietet sich im Luftraum jede Oberfläche als Adsorptionsfläche an. In der Folge sind chemische Reaktionen zu erwarten. Eine davon, die Nitrierung, führt zu einer stärkeren Reaktion von Allergikern auf die Pollen. Treibend ist die Gegenwart von Ozon.
Blassbraun statt sattgelb
Authors: Fischer‐Henningsen Doris
Published: June 2011

Vincent van Gogh verwendete gern leuchtende Farben, die seinen Bildern die charakteristische Ausdruckskraft verleihen. Besonders das Chromgelb kam oft auf die Leinwand und droht dort langsam zu einem Braunton zu verblassen und die Bilder zu verfälschen. Ursache ist offenbar die Reduktion des Chrom(VI)‐Pigmentes zu Chrom(III)‐Verbindungen.
Adsorption equilibrium, thermodynamics, kinetics, mechanism and process design of zinc(II) ions onto cashew nut shell
Authors: SenthilKumar P. , Ramalingam S. , Abhinaya R. V. , Kirupha S. Dinesh , Vidhyadevi T. , Sivanesan S.
Published: June 2011

Cashew nut shell (CNS) is an agricultural waste was investigated as a new adsorbent for the removal of zinc(II) from aqueous environment. Effects of solution pH, CNS dose, contact time, initial zinc(II) concentration and temperature on removal efficiency were tested and optimum conditions were evaluated. The equilibrium data were fitted well with Langmuir isotherm model and pseudo‐second‐order kinetic model. Langmuir monolayer adsorption capacity of CNS was examined as 24.98 mg/g. Changes in standard Gibbs free energy (▵G°), standard enthalpy (▵H°) and standard entropy (▵S°) showed that the sorption of zinc(II) ions onto CNS are spontaneous and exothermic at 303–333 K. Sorption process was found to be controlled by both surface and pore diffusion. A batch adsorber was designed for different CNS dose to effluent volume ratios using Langmuir equation. Effective diffusivity values were found to be 1.927 × 10−11 (10 mg/L), 2.135 × 10−11 (20 mg/L), 2.267 × 10−11 (30 mg/L), 2.305 × 10−11 (40 mg/L) and 2.362 × 10−11 (50 mg/L) m2/s. © 2011 Canadian Society for Chemical Engineering
Surface immobilisation of fluorinated polystyrene‐acrylate latex nanoparticles with core–shell structure by crosslinking
Authors: Xu G. L. , Liang Y. , Wen X. F. , Pi P. H. , Zheng D. F. , Cheng J. , Yang Z. R.
Published: June 2011

Fluorinated polystyrene‐acrylate (PSA) latex nanoparticles with core–shell structure were synthesised by two‐stage seeded emulsion polymerisation method in the presence of reactive emulsifier DNS‐86. Diallyl phthalate (DAP) and Vinyltriethoxysilicone (VTES) were used as crosslinking agent to immobilise the fluorinated copolymer on the surface of the latex film. Fourier transform infrared spectroscopy (FTIR) spectra show that fluorine and siloxane monomers were effectively involved in the emulsion copolymerisation. Transmission electron microscope (TEM) observation shows that the prepared emulsion particles had a core–shell structure with fluorinated copolymer in the shell. X‐ray photoelectron spectroscopy (XPS) analysis reveals that fluorine atom has the tendency of migrating to the film–air interface and the incorporation of VTES helps the migration of fluorine atom towards the film–air interface. Water contact angle (WCA) test proved that DAP and VTES as crosslinking agent can immobilise the fluorinated copolymer on the surface of the latex films. © 2011 Canadian Society for Chemical Engineering
Efficient inducible Pan‐neuronal cre‐mediated recombination in SLICK‐H transgenic mice
Authors: Heimer‐McGinn Victoria , Young Paul
Published: June 2011

Large‐scale functional genomics in mice is becoming feasible through projects to develop conditional knockout alleles for every gene. Inducible neuron‐specific gene knockout in such mice will permit the analysis of neuronal phenotypes while circumventing developmental defects or embryonic lethality. Here we describe a transgenic line, termed SLICK‐H, that facilitates widespread inducible conditional genetic manipulation within most populations of projection neurons. In SLICK‐H mice, the Thy1 promoter drives robust and relatively uniform expression of a drug‐inducible form of cre recombinase throughout the peripheral and central nervous system. This permits efficient induction of cre‐mediated genetic manipulation upon tamoxifen administration in adult mice. Importantly, cre activity in the absence of tamoxifen is minimal, permitting tight control of recombination. In the present study, we catalog in detail the transgene expression patterns and recombination efficiencies in SLICK‐H mice. Our results highlight the utility of SLICK‐H mice for functional genomics in the nervous system. genesis 49:942–949, 2011. © 2011 Wiley Periodicals, Inc.
Position matters: Variability in the spatial pattern of BMP modulators generates functional diversity
Authors: Araujo Helena , Fontenele Marcio Ribeiro , da Fonseca Rodrigo Nunes
Published: June 2011

Bone morphogenetic proteins (BMPs) perform a variety of functions during development. Considering a single BMP, what enables its multiple roles in tissues of varied sizes and shapes? What regulates the spatial distribution and activity patterns of the BMP in these different developmental contexts? Some BMP functions require controlling spread of the BMP morphogen, while others require formation of localized, high concentration peaks of BMP activity. Here we review work in Drosophila that describes spatial regulation of the BMP encoded by decapentaplegic (dpp) indifferent developmental contexts. We concentrate on extracellular modulation of BMP function and discuss the mechanisms that generate concentrated peaks of Dpp activity, subdivide territories of different activity levels or regulate spread of the Dpp morphogen from a point source. We compare these findings with data from vertebrates and non‐model organisms to discuss how changes in the regulation of Dpp distribution by extracellular modulators may lead to variability in dpp function in different species. genesis 49:698–718, 2011. © 2011 Wiley‐Liss, Inc.
On the relative impact of subgrid‐scale modelling and conjugate heat transfer in LES of hot jets in cross‐flow over cold plates
Authors: Hallez Y. , Jouhaud J.‐C. , Poinsot T. J.
Published: June 2011

This work describes numerical simulations of a hot jet in cross‐flow with applications to anti‐ice systems of aircraft engine nacelles. Numerical results are compared with experimental measurements obtained at ONERA to evaluate the performances of LES in this industrial context. The combination of complex geometries requiring unstructured meshes and high Reynolds number does not allow the resolution of boundary layers so that wall models must be employed. In this framework, the relative influence of subgrid‐scale modelling and conjugate heat transfer in LESs of aerothermal flows is evaluated. After a general overview of the transverse jet simulation results, a LES coupled with a heat transfer solver in the walls is used to show that thermal boundary conditions at the wall have more influence on the results than subgrid scale models. Coupling fluid flow and heat transfer in solids simulations is the only method to specify their respective thermal boundary conditions. Copyright © 2011 John Wiley & Sons, Ltd.
RESERVE CAPACITY OF PUBLIC AND PRIVATE HOSPITALS IN RESPONSE TO DEMAND UNCERTAINTY
Authors: Rodriguez‐Alvarez Ana , Roibás David , Wall Alan
Published: June 2011

A feature of hospitals is that they face uncertain demand for the services they offer. To cover fluctuations in demand, they need to maintain reserve service capacity in the form of beds, equipment, personnel, etc. to minimize the probability of excess queuing or turning away patients, creating a trade‐off between reserve service capacity and economic costs. Using a simple theoretical framework, we show how the reserve capacity established depends on institutional characteristics that can affect the objective of the hospital. In particular, we show that private and public hospitals may provide different levels of reserve capacity. In an empirical application using a panel data set of Spanish hospitals over the period 1996–2006, we model reserve service capacity using a distance frontier approach. Our results show that private hospitals generally react to a lesser extent to demand uncertainty than public hospitals. Copyright © 2011 John Wiley & Sons, Ltd.
Stepwise disproportionation in polyelectrolyte complexes
Authors: Dias R. S. , Linse P. , Pais A. A. C. C.
Published: June 2011

Structural properties and the topology of polyelectrolyte complexes (PECs) formed in solution have been investigated under different conditions by Monte Carlo simulations using a coarse‐grained model. The extension of individual polyions has been characterized by their radius of gyration, whereas the composition of the complexes has been investigated by their net charge and their internal topological structure by a novel analysis describing how the shorter polycations link to monomers of the longer polyanion. Conditions have been found at which the polyanion and a given number of polycations form distinguishable complexes differing in (i) the polyanion conformation and (ii) the fraction of polycations being in extended and collapsed states. Thus, at equilibrium, these PECs display a stepwise variation of the degree of intrachain disproportionation within the polyanion (also referred to as intrachain segregation), concomitant with the interchain disproportionation of the polycations, which is in agreement with previous theoretical predictions. The coexistence of the different polyelectrolyte complex structures appears, generally, at mixing ratios close to but different from charge equivalence and, as a consequence, broad polyelectrolyte size distributions are commonly obtained. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Integral trees of odd diameters
Authors: Ghorbani E. , Mohammadian A. , Tayfeh‐Rezaie B.
Published: June 2011

A graph is called integral if all eigenvalues of its adjacency matrix consist entirely of integers. Recently, Csikvári proved the existence of integral trees of any even diameter. In the odd case, integral trees have been constructed with diameter at most 7. In this article, we show that for every odd integer n>1, there are infinitely many integral trees of diameter n. © 2011 Wiley Periodicals, Inc. J Graph Theory
Cyanidin‐3‐glucoside ameliorates ethanol neurotoxicity in the developing brain
Authors: Ke Zunji , Liu Ying , Wang Xin , Fan Zhiqin , Chen Gang , Xu Mei , Bower Kimberley A. , Frank Jacqueline A. , Ou Xiaoming , Shi Xianglin , Luo Jia
Published: June 2011

Ethanol exposure induces neurodegeneration in the developing central nervous system (CNS). Fetal alcohol spectrum disorders (FASD) are caused by ethanol exposure during pregnancy and are the most common nonhereditary cause of mental retardation. It is important to identify agents that provide neuroprotection against ethanol neurotoxicity. Multiple mechanisms have been proposed for ethanol‐induced neurodegeneration, and oxidative stress is one of the most important mechanisms. Recent evidence indicates that glycogen synthase kinase 3β (GSK3β) is a potential mediator of ethanol‐mediated neuronal death. Cyanidin‐3‐glucoside (C3G), a member of the anthocyanin family, is a potent natural antioxidant. Our previous study suggested that C3G inhibited GSK3β activity in neurons. Using a third trimester equivalent mouse model of ethanol exposure, we tested the hypothesis that C3G can ameliorate ethanol‐induced neuronal death in the developing brain. Intraperitoneal injection of C3G reduced ethanol‐meditated caspase‐3 activation, neurodegeneration, and microglial activation in the cerebral cortex of 7‐day‐old mice. C3G blocked ethanol‐mediated GSK3β activation by inducing phosphorylation at serine 9 while reducing the phosphorylation at tyrosine 216. C3G also inhibited ethanol‐stimulated expression of malondialdehyde (MDA) and p47phox, indicating that C3G alleviated ethanol‐induced oxidative stress. These results provide important insight into the therapeutic potential of C3G. © 2011 Wiley‐Liss, Inc.
New treatment for peripheral nerve defects: Reconstruction of a 2 cm, monkey median nerve gap by direct lengthening of both nerve stumps
Authors: Hara Yuki , Nishiura Yasumasa , Ochiai Naoyuki , Sharula  , Nakajima Yoshiko , Kubota Shigeki , Saijilafu  , Mishima Hajime
Published: June 2011

We have developed a new treatment for peripheral nerve defects: nerve‐lengthening method, and confirmed the efficacy and safety of our method using cynomolgus monkeys. A 20‐mm defect in the median nerve of monkey's forearms was repaired through the simultaneous lengthening of both nerve stumps with original nerve‐lengthening device. To evaluate nerve regeneration after neurorrhaphy, electrophysiological, histological, and functional recovery were examined and compared to the standard autografting. Nerve conduction velocity, axon maturation, and the result of functional test were superior in the nerve‐lengthening method than in the autografting. And there were no adverse events associated with our method. We concluded that this method is practical for clinical application. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:153–161, 2012
Reversed‐phase monoliths prepared by UV polymerization of divinylbenzene
Authors: Flook Kelly , Agroskin Yury , Pohl Chris
Published: June 2011

Many different techniques have been developed to prepare monolithic materials specifically for chromatographic techniques. The two most popular polymerization techniques being thermal or via ultra violet (UV) light. Whereas thermal polymerization is easily employed for a whole variety of monomer and porogen systems, UV polymerization has been limited to methacrylate‐based systems, and styrenic systems have been avoided due to their strong absorbance at low wavelengths. By careful consideration of wavelength, initiator and other system components, it was proven that reversed‐phase columns for the separation of proteins and peptides can be prepared using divinylbenzene through UV initiation of 2‐methyl‐4′‐(methylthio)‐2‐morpholinopropiophenone at a wavelength of 350 nm.
Intraoperative tumor localization with surgeon‐performed ultrasound‐guided needle dye injection
Authors: Ryan William R. , Orloff Lisa A.
Published: June 2011

Objectives:

To describe our technique and initial experience of intraoperative tumor localization with surgeon‐performed ultrasound‐guided needle dye injection.

Study Design:

Prospective case series. Technique description.

Methods:

Using surgeon‐performed ultrasonography (SP‐US), 20 tumors (lymph node metastases of papillary thyroid carcinoma [15], Hurthle cell carcinoma [2], medullary thyroid carcinoma [1], and lymphoma [1], and a parathyroid adenoma [1]) were localized in 13 patients. With ultrasound guidance, 0.1 mL of 1% methylene blue dye was injected into each targeted tumor. The blue color in contrast helped guide the dissection. Sixteen of 20 (80%) of dissections were revision cases through scar.

Results:

Using SP‐US and US‐guided injection with blue dye, 20 of 20 (100%) of cases were successful in retrieving the target tumor with no inadvertent nerve injuries (nerves at risk in scar: recurrent laryngeal [12], phrenic [3], vagus [3], and sympathetic chain [3]). Dye injection adds 5 to 10 minutes of time prior to incision. Injections appeared to increase visual differentiation of tissue, save time during dissection, particularly during revision dissections, and help ensure successful target retrieval. Injection into a parathyroid adenoma resulted in an overabundance of blue dye in nontumor tissue.

Conclusions:

Surgeon‐performed ultrasound guided needle dye injection is particularly helpful in directing the surgeon to the appropriate area for tumor resection in fibrotic areas and thereby possibly reducing surgical time, sampling error, and morbidity. A lower concentration or a different dye may be more helpful for parathyroid adenomas. Further study on this technique is needed and is under way with a larger group of patients.

Educational Objective:

At the conclusion of this manuscript, the participants should be able to understand the technique and advantages of intraoperative tumor localization with surgeon‐performed ultrasound‐guided needle blue dye injection.
Cyclic adenosine 3′,5′-monophosphate in rat steatotic liver transplantation
Authors: Jimenez-Castro Monica B. , Casillas-Ramirez Arani , Massip-Salcedo Marta , Elias-Miro Maria , Serafin Anna , Rimola Antoni , Rodes Juan , Peralta Carmen
Published: June 2011

Numerous steatotic livers are discarded as unsuitable for transplantation (TR) because of their poor tolerance of ischemia/reperfusion (I/R). Cyclic adenosine 3′,5′-monophosphate (cAMP)–elevating agents protect against I/R injury both in nonsteatotic livers that have been removed from non–heart-beating donors and subjected to warm ischemia or cold ischemia (CIS) and in perfused, isolated livers. Ischemic preconditioning (PC), which is based on brief periods of I/R, protects steatotic liver grafts, but the mechanism that is responsible is poorly understood. This study examines the role of cAMP in the vulnerability shown by steatotic livers to TR-associated I/R injury and the benefits of PC in this situation. Steatotic livers with or without PC were transplanted into Zucker rats. The hepatic levels of cAMP were measured and altered pharmacologically. Our results indicate that the cAMP levels in the nonsteatotic liver grafts were similar to those found in a sham group. However, high cAMP levels were observed in steatotic liver grafts. The blockage of cAMP generation by adenylate cyclase inhibitor pre-treatment or PC had the following results: reduced hepatic injury and increased survival of steatotic graft recipients; greater preservation of adenosine triphosphate (ATP) and reduced lactate accumulation throughout CI. This blockade of cAMP by a nitric oxide–dependent mechanism protected steatotic liver grafts against oxidative stress and microvascular disorders after reperfusion. In conclusion, cAMP blocking–based strategies could protect patients against the inherent risk of steatotic liver failure after TR. Liver Transpl 17:1099–1099, 2011. © 2011 AASLD.
The relation between cognition and motor dysfunction in drug‐naive newly diagnosed patients with Parkinson's disease
Authors: Domellöf Magdalena Eriksson , Elgh Eva , Forsgren Lars
Published: June 2011

Recent studies have reported cognitive decline to be common in the early phase of Parkinson's disease. Imaging data connect working memory and executive functioning to the dopamine system. It has also been suggested that bradykinesia is the clinical manifestation most closely related to the nigrostriatal lesion. Exploring the relationship between motor dysfunction and cognition can help us find shared or overlapping systems serving different functions. This relationship has been sparsely investigated in population‐based studies of untreated Parkinson's disease. The aim of the present study was to investigate the association between motor signs and cognitive performance in the early stages of Parkinson's disease before the intake of dopaminergic medication. Patients were identified in a population‐based study of incident cases with idiopathic parkinsonism. Patients with the postural instability and gait disturbances phenotype were compared with patients with the tremor‐dominant phenotype on demographics and cognitive measures. Associations between cognitive and motor scores were investigated, with age, education, and sex controlled for. Bradykinesia was associated with working memory and mental flexibility, whereas axial signs were associated with episodic memory and visuospatial functioning. No significant differences in the neuropsychological variables were found between the postural instability and gait disturbances phenotype and the tremor phenotype. Our results indicate a shared system for slow movement and inflexible thinking that may be controlled by a dopaminergic network different from dopaminergic networks involved in tremor and/or rigidity. The association between axial signs and memory and visuospatial function may point to overlapping systems or pathologies related to these abilities. © 2011 Movement Disorder Society
Assessment of involuntary choreatic movements in Huntington's disease—Toward objective and quantitative measures
Authors: Reilmann Ralf , Bohlen Stefan , Kirsten Florian , Ringelstein E. Bernd , Lange Herwig W.
Published: June 2011

Objective measures of motor impairment may improve the sensitivity and reliability of motor end points in clinical trials. In Huntington's disease, involuntary choreatic movements are one of the hallmarks of motor dysfunction. Chorea is commonly assessed by subitems of the Unified‐Huntington's Disease Rating Scale. However, clinical rating scales are limited by inter‐ and intrarater variability, subjective error, and categorical design. We hypothesized that assessment of position and orientation changes interfering with a static upper extremity holding task may provide objective and quantitative measures of involuntary movements in patients with Huntington's disease. Subjects with symptomatic Huntington's disease (n = 19), premanifest gene carriers (n = 15; Unified‐Huntington's Disease Rating Scale total motor score ≤ 3), and matched controls (n = 19) were asked to grasp and lift a device (250 and 500 g) equipped with an electromagnetic sensor. While subjects were instructed to hold the device as stable as possible, changes in position (x, y, z) and orientation (roll, pitch, yaw) were recorded. These were used to calculate a position index and an orientation index, both depicting the amount of choreatic movement interfering with task performance. Both indices were increased in patients with symptomatic Huntington's disease compared with controls and premanifest gene carriers for both weights, whereas only the position index with 500 g was increased in premanifest gene carriers compared with controls. Correlations were observed with the Disease Burden Score based on CAG‐repeat length and age and with the Unified‐Huntington's Disease Rating Scale. We conclude that quantitative assessment of chorea is feasible in Huntington's disease. The method is safe, noninvasive, and easily applicable and can be used repeatedly in outpatient settings. A use in clinical trials should be further explored in larger cohorts and follow‐up studies. © 2011 Movement Disorder Society
Do nonmotor symptoms in Parkinson's disease differ from normal aging?
Authors: Krishnan Syam , Sarma Gangadhara , Sarma Sankara , Kishore Asha
Published: June 2011

Background:

Nonmotor symptoms in Parkinson's disease are frequent and affect health‐related quality of life of patients. The severity and domains of nonmotor symptoms involved in Parkinson's disease and normal aging have not been compared before.

Methods:

We performed a prospective case–control study to assess the frequency and severity of nonmotor symptoms in patients with Parkinson's disease (n = 174) and age‐matched normal controls (n = 128) using the Non‐Motor Symptoms Scale.

Results:

Nonmotor symptoms in Parkinson's disease were ubiquitous, more frequent, and more severe than in normal aging, particularly in women. Cardiovascular, mood/cognition, and perceptual problems/hallucinations domains were rarely involved in age‐matched controls. Age had no effect and sex some influence on nonmotor symptoms in Parkinson's disease. In contrast, in controls, nonmotor symptoms increased with age, and sex had no effect.

Conclusions:

Nonmotor symptoms in Parkinson's disease differ from those in aging in frequency, severity, sex predilection, and domain involvement. © 2011 Movement Disorder Society
Genetic modifications of pigs for medicine and agriculture
Authors: Whyte Jeffrey J. , Prather Randall S.
Published: June 2011

Genetically modified swine hold great promise in the fields of agriculture and medicine. Currently, these swine are being used to optimize production of quality meat, to improve our understanding of the biology of disease resistance, and to reduced waste. In the field of biomedicine, swine are anatomically and physiologically analogous to humans. Alterations of key swine genes in disease pathways provide model animals to improve our understanding of the causes and potential treatments of many human genetic disorders. The completed sequencing of the swine genome will significantly enhance the specificity of genetic modifications, and allow for more accurate representations of human disease based on syntenic genes between the two species. Improvements in both methods of gene alteration and efficiency of model animal production are key to enabling routine use of these swine models in medicine and agriculture. Mol. Reprod. Dev. 78:879–891, 2011. © 2011 Wiley Periodicals, Inc.
Reifende Biotechindustrie
Authors: Bengs Holger
Published: June 2011

Steigender Umsatz, wachsende Unternehmenszahlen, wieder Gründungen, frisches Eigenkapital, mehr Mitarbeiter: Die Biotechbranche wuchs im Jahr 2010 und hat dennoch ein Problem.
Nicht nur Schulwissen auffrischen: Vorkurse in Chemie
Authors: Parchmann Ilka , Busker Maike , Klostermann Mareike , Herzog Stefanie , Huber Angelika
Published: June 2011

Die Abbruchquoten in mathematisch‐naturwissenschaftlichen Studiengänge sind hoch:1,2 Im Jahr 2006 gaben 28 Prozent der Studierenden ihr Studium auf. Rechnet man Fachwechsel mit ein, sind die Zahlen noch dramatischer: Nur etwa jeder zweite Studierende der Chemie beendet sein Studium mit einem Abschluss. Sind Studienanfänger ausreichend auf ein Chemiestudium vorbereitet?
Replica time integrators
Authors: Venturini G. , Yang J. Z. , Ortiz M. , Marsden J. E.
Published: June 2011

This paper is concerned with the classical problem of wave propagation in discrete models of nonuniform spatial resolution. We develop a new class of Replica Time Integrators (RTIs) that permit the two‐way transmission of thermal phonons across mesh interfaces. This two‐way transmissibility is accomplished by representing the state of the coarse regions by means of replica ensembles, consisting of collections of identical copies of the coarse regions. In dimension d, RTIs afford an O(nd) speed‐up factor in sequential mode, and O(nd + 1) in parallel, over regions that are coarsened n‐fold. In this work, we restrict ourselves to the solution of the 3d continuous wave equation, for both linear and non‐linear materials. By a combination of phase‐error analysis and numerical testing, we show that RTIs are convergent and result in exact two‐way transmissibility at the Courant–Friedrichs–Lewy limit for any angle of incidence. In this limit, RTIs allow step waves and high‐frequency harmonics to cross mesh interfaces in both directions without internal reflections or appreciable loss or addition of energy. The possible connections of RTIs with discrete‐to‐continuum approaches and, in particular, with the transition between molecular dynamics and continuum thermodynamics are also pointed to by way of future outlook. Copyright © 2011 John Wiley & Sons, Ltd.
Fracture in magnetoelectroelastic materials using the extended finite element method
Authors: Rojas‐Díaz R. , Sukumar N. , Sáez A. , García‐Sánchez F.
Published: June 2011

Static fracture analyses in two‐dimensional linear magnetoelectroelastic (MEE) solids is studied by means of the extended finite element method (X‐FEM). In the X‐FEM, crack modeling is facilitated by adding a discontinuous function and the crack‐tip asymptotic functions to the standard finite element approximation using the framework of partition of unity. In this study, media possessing fully coupled piezoelectric, piezomagnetic and magnetoelectric effects are considered. New enrichment functions for cracks in transversely isotropic MEE materials are derived, and the computation of fracture parameters using the domain form of the contour interaction integral is presented. The convergence rates in energy for topological and geometric enrichments are studied. Excellent accuracy of the proposed formulation is demonstrated on benchmark crack problems through comparisons with both analytical solutions and numerical results obtained by the dual boundary element method. Copyright © 2011 John Wiley & Sons, Ltd.
Combining cone calorimeter and PCFC to determine the mode of action of flame‐retardant additives
Authors: Sonnier R. , Ferry L. , Longuet C. , Laoutid F. , Friederich B. , Laachachi A. , Lopez‐Cuesta J‐M.
Published: June 2011

The flammability of various flame‐retarded formulations containing different hydrated mineral fillers and/or phosphorous compounds and/or carbon nanotubes has been investigated using both a cone calorimeter and a pyrolysis combustion flow calorimeter (PCFC). A method was proposed to evaluate the barrier effect of the flame‐retardant additives. This method is based on the fact that the PCFC is non‐sensitive to physical flame‐retardant effects whereas both chemical and physical phenomena have a great effect on cone calorimeter results. Therefore, normalized peak of heat release rate (pHRR) values obtained with both techniques do not always show a good correlation. It was highlighted that the mismatch between both pHRR results was related to the formation of a protective layer during combustion. Protective layers have been evidenced independently by visual observations. Thus, it is proposed that the magnitude of the deviation from a perfect correlation between cone calorimeter and PCFC pHRRs could be used to quantify the magnitude of barrier effect. Although the results obtained from different fire tests are generally not correlated, such an approach based on the complementarity of different techniques appears more relevant despite of its empirical nature. Copyright © 2011 John Wiley & Sons, Ltd.