bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal‐Free Activation in the Anionic Ring‐Opening Polymerization of Cyclopropane Derivatives
Authors: Illy Nicolas , Boileau Sylvie , Penelle Jacques , Barbier Valessa 
Published: August 2009

AbstractThe successful activation observed when using ButP4 phosphazene base and thiophenol or bisthiols for the anionic ring opening polymerization (ROP) of di‐n‐propyl cyclopropane‐1,1‐dicarboxylate is described. Well‐defined monofunctional or difunctional polymers with a very narrow molecular weight distribution were obtained through a living process. Quantitative end‐capping of the propagating malonate carbanion was accessible by using either an electrophilic reagent such as allyl bromide or a strong acid such as HCl. Kinetics studies demonstrated a much higher reactivity compared to the conventional route using alkali metal thiophenolates.magnified image
Development and application of novel ring‐opening polymerizations to functional networked polymers
Authors: Endo Takeshi , Sudo Atsushi 
Published: August 2009

AbstractThis Highlight gives an overview of the recent progress in development of new ring‐opening polymerizations (ROPs) and their applications to functional networked polymers in our group. The described ROPs involve thermally induced polymerization of 1,3‐benzoxazine, anionic alternating copolymerizations of epoxides and lactones, and those exhibiting equilibrium nature. These ROPs were successfully applied to the syntheses of the relevant networked polymers, leading to their distinctive features such as high thermal stability, small volume shrinkage, and selective decrosslinking ability, which enabled design and development of next generation materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4847–4858, 2009
Study of Inductive Coupled Hydrogen and Argon Plasma Interaction with SiO2 Glass
Authors: Skudra Atis , Revalde Gita , Gavare Zanda , Zorina Natalia 
Published: August 2009

AbstractThis work is devoted to the diagnostics of interaction between hydrogen and argon with the surface of SiO2 glass walls. For diagnostics of the interaction, special high‐frequency electrodeless light sources were prepared, filled with pure argon of 1 Torr or argon‐hydrogen of total pressure of 1 Torr (Ar/H2 mixing ratio is 9:1). Besides the mostly used spherical and cylindrical lamps, dumbbell type lamps have also been investigated. The spectroscopic and AFM measurements showed that in comparison with pure argon plasma, the argon‐hydrogen plasma causes non‐uniform changes of the SiO2 surface. For these modifications active OH are primarily responsible molecules, created in the reactions of hydrogen molecules with oxygen molecules, adsorbed from the walls.
Properties of ta‐C Films for Tools and Machinery Parts
Authors: Präßler Frank , Grimm Werner , Chudoba Thomas 
Published: August 2009

AbstractThe pulsed vacuum arc discharge is an effective technology for the deposition of ta‐C coatings on tools and machinery parts. The properties of these carbon coatings differ substantially from conventional hard nitride films particularly with regard to hardness and wear‐resistance. The paper shows analytical results of ta‐C films in comparison to such hard coatings. Thereby different methods are applied for determination of adhesion, friction, wear‐resistance, and indentation hardness. A simple correlation was found between indentation hardness and wear‐resistance over a wide range of hard materials. Furthermore, all investigated films have a strong adhesion on steel in conventional Rockwell tests. But in scratch tests with increasing normal forces brittle ta‐C films delaminate at lower forces from the surface compared to nitride coatings.
Gas Phase Modification of Superhard Carbon Coatings Deposited by Pulsed DC‐Arc‐Process
Authors: Grimm Werner , Weihnacht Volker 
Published: August 2009

AbstractThe pulsed vacuum arc discharge (pulsed arc) is the most efficient PVD technology for deposition of hard amorphous carbon coatings on tools and machinery parts. Due to the pulsed arc discharge a stable evaporation process and the efficient deposition of hydrogen‐free a‐C type coatings is possible. This paper shows that the pulsed arc enables the deposition of ta‐C and modified a‐C coatings with interesting coating properties in a wide pressure range of argon, acetylene and ammonia gas atmosphere. Coatings with different gas flow rates of these gases were deposited on steel substrates. The coating properties were characterized by using different analytical methods for determination of structure, hardness, friction and wear behaviour. The changes of film properties in dependence of the kind and the rate of gas flow are compared and discussed.
Characterization of a N2/CH4 Microwave Plasma With a Solid Additive Si Source Used for SiCN Deposition
Authors: Bulou Simon , Le Brizoual Laurent , Hugon Robert , De Poucques Ludovic , Belmahi Mohammed , Migeon Henri‐Noël , Bougdira Jamal 
Published: August 2009

AbstractMicrowave plasma assisted chemical vapour deposition of CH4/N2 gas mixture using an additive solid silicon is used to synthesize SiCN. To better understand the mechanisms involved, species such as C, Si, NH, CN, C2 and N2 are observed by means of optical emission spectroscopy. In situ Fourier transform infrared spectroscopy (FTIR) is used as a plasma diagnostic and CH4, NH3, HCN and C2H2 have been detected. Deposits are achieved at various CH4 ratios (1, 4 and 8%) and analysed by means of scanning electron microscopy, energy dispersion X‐ray spectroscopy and FTIR spectroscopy. Adding a silicon source permits to obtain thicker layers confirming the major role of Si in the carbonitride deposition process. Deposits obtained at 8% of CH4 have a composition about 35% of Si, 30% C and 30% N and showed evidence of ternary SiCN system.
Effect of Methane Pressure on the Size of Carbon Nanoparticles Deposited by Pulsed Plasma Enhanced Chemical Vapor Deposition
Authors: Rastkar Ahmad R. , Shokri Babak , Kabir Mojtaba , Amirzadeh Maria , Rahimipour Mohammad R. 
Published: August 2009

AbstractThe nanoparticles of carbon were deposited from methane under the potential of a pulsed direct current discharge. The deposition was carried without external heating. The size, chemistry, and structure of carbon nanoparticles were characterized using transmission electron microscopy (TEM), X‐ray diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy. The minimum size of the nanoparticles was as low as 10 nm as shown by TEM. The nanocrystalline or amorphous structure of the particles was revealed by XRD. Raman spectroscopy indicated on the sp2 bonds of carbon and FTIR spectroscopy identified the other bonds of carbon.
The protective effect of diabetes mellitus against prostate cancer: Role of sex hormones
Authors: Baradaran N. , Ahmadi H. , Salem S. , Lotfi M. , Jahani Y. , Baradaran N. , Mehrsai A.R. , Pourmand G. 
Published: August 2009

AbstractBACKGROUNDDiabetes mellitus (DM) has been associated with decreased risk of prostate cancer (PC) in several reports. Hormonal environment of diabetic patients is believed to be an important contributing factor in this regard.METHODSUsing data from a multi‐center case–control study in Iran, base line testosterone, sex hormone binding globulin (SHBG), estradiol, and albumin levels as well as thorough demographic and medical characteristics of 194 newly diagnosed prostate cancer patients were determined. There were 317 ethnicity‐matched men with no cancer as controls as well. Data was analyzed for hormones of interest in DM patients regarding their cancer status.RESULTSOf 511 enrolled patients, twenty‐one cases and 63 controls were diagnosed as DM. Patients with DM were significantly less likely to have PC (OR: 0.44, P = 0.003). Time since DM diagnosis was also inversely correlated with the risk of cancer (P trend < 0.0001). Control patients had significantly higher testosterone, estradiol, and testosterone/SHBG ratio (P < 0.05). As time since DM diagnosis increased by quartiles, testosterone significantly increased (P trend < 0.05). The risk of PC also significantly declined (P trend < 0.0001) following an initial remarkable increase early after DM diagnosis. After including the hormones in the logistic regression model, there was a weak, yet significant inverse association of testosterone/SHBG and DM duration with the risk of PC.CONCLUSIONSBased on our results DM duration is inversely correlated with the risk of prostate cancer. Our results do not support the hypothesis that sex hormones, including testosterone, play a major role in the protective effect of DM against PC. Prostate 69: 1744–1750, 2009. © 2009 Wiley‐Liss, Inc.
The expression of androgen‐responsive genes is Up‐Regulated in the epithelia of benign prostatic hyperplasia
Authors: O'Malley Katherine J. , Dhir Rajiv , Nelson Joel B. , Bost James , Lin Yan , Wang Zhou 
Published: August 2009

AbstractBACKGROUNDBenign prostatic hyperplasia (BPH) is one of the most common diseases among aging men in the United States. In addition to aging, the presence of androgens is another major risk factor in BPH development. However, whether androgen signaling is altered in BPH remains unclear. To determine androgen signaling in BPH, we characterized the expression of four different androgen‐responsive genes, Eaf2/U19, ELL2, FKBP5, and PSA, in BPH and adjacent normal glandular epithelial cells.METHODSA set of 17 BPH specimens were resected from patients over 60 years of age with clinical symptoms of BPH. Laser‐capture microdissection (LCM) was used to isolate glandular epithelial cells from BPH areas and adjacent normal areas, separately. LCM isolated cells from individual specimens were lysed and RNA isolation, reverse transcription, and real‐time PCR were performed using CellsDirect™ One‐Step qRT‐PCR Kit (Invitrogen, Carlsbad, CA).RESULTSAll of the assayed genes displayed increased expression, from ∼2‐ to ∼6‐fold, in BPH as compared to the adjacent normal epithelial cells. We also generated a composite androgen response index based on the expression levels of the four genes, which provides a reliable readout for overall androgen action. Our study showed that the composite androgen response index in BPH is ∼4‐fold as compared to that in the adjacent normal tissues.CONCLUSIONSAndrogen signaling is significantly elevated in BPH relative to the adjacent normal prostate. Understanding the mechanisms causing elevated androgen signaling may lead to novel approaches for prevention and/or treatment of BPH. Prostate 69: 1716–1723, 2009. © 2009 Wiley‐Liss, Inc.
Dielectric and piezoelectric properties of (Bi0.9Li0.10)(Sc0.90Ta0.10)O3PbTiO3 high‐temperature relaxor piezoelectric ceramics
Authors: Zhao Yi , Jiang Yihang , Zhu Jianguo 
Published: August 2009

Abstract(1 − x)(Bi0.90Li0.10)(Sc0.90Ta0.10)O3xPbTiO3 (BLSTPTx; x = 0.60–0.65) ceramics were prepared using the conventional mixed oxide method. X‐ray diffraction analysis revealed that BLSTPTx has a pure perovskite structure. In the vicinity of the morphotropic phase boundary, which was observed in the compositional range 0.61 ≤ x ≤ 0.62 from phase structure measurements, the BLSTPTx ceramics showed enhanced piezoelectric properties: piezoelectric constant d33 = 516 pC/N, planar electromechanical coupling factors kp = 57%. The temperature of the permittivity maximum increased with increasing measurement frequency, over the range 302–313 °C, higher than that of conventional relaxor materials such as Pb(B1B2)O3PbTiO3 systems. The ceramics show relaxor ferroelectric features.
Analytic normal forms and symmetries of strict feedforward control systems
Authors: Tall Issa Amadou , Respondek Witold 
Published: August 2009

AbstractThis paper deals with the problem of convergence of normal forms of control systems. We identify ann‐dimensional subclass of control systems, calledspecial strict feedforward form, shortly (SSFF), possessing a normal form which is a smooth (resp. analytic) counterpart of the formal normal form of Kang. We provide a constructive algorithm and illustrate by several examples including the Kapitsa pendulum and the cart–pole system. The second part of the paper is concerned about symmetries of single‐input control systems. We show that any symmetry of a smooth system in SSFF is conjugated to ascaling translationand any 1‐parameter family of symmetries is conjugated to a family of scaling translations along the first variable. We compute explicitly those symmetries by finding the conjugating diffeomorphism. We illustrate our results by computing the symmetries of the cart–pole system. Copyright © 2009 John Wiley & Sons, Ltd.
Gene expression associations with the growth inhibitory effects of small molecules on live cells: Specificity of effects and uniformity of mechanisms
Authors: Shedden Kerby , Yang Yang , Rosania Gus 
Published: August 2009

AbstractThe NCI60 human tumor cell line screen is a public resource for studying selective and nonselective growth inhibition of small molecules against cancer cells. By coupling growth inhibition screening data with biological characterizations of the different cell lines, it becomes possible to infer mechanisms of action underlying some of the observable patterns of selective activity. Using these data, mechanistic relationships have been identified including specific associations between single genes and small families of closely related compounds, and less specific relationships between biological processes involving several cooperating genes and broader families of compounds. Here, we aim to characterize the degree to which such specific and general relationships are present in these data. A related question is whether genes tend to act with a uniform mechanism for all associated compounds, or whether multiple mechanisms are commonly involved. We address these two issues in a statistical framework placing special emphasis on the effects of measurement error in the gene expression and chemical screening data. We find that as measurement accuracy increases, the pattern of apparent associations shifts from one dominated by isolated gene/compound pairs, to one in which families consisting of an average of 25 compounds are associated to the same gene. At the same time, the number of genes that appear to play a role in influencing compound activities decreases. For less than half of the genes, the presence of both positive and negative correlations indicates pleiotropic associations with molecules via different mechanisms of action. Copyright © 2009 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 2: 175–185, 2009
Adipose-Derived Mesenchymal Stem Cells Ameliorate Chronic Experimental Autoimmune Encephalomyelitis
Authors: Constantin Gabriela , Marconi Silvia , Rossi Barbara , Angiari Stefano , Calderan Laura , Anghileri Elena , Gini Beatrice , Dorothea Bach Simone , Martinello Marianna , Bifari Francesco , Galiè Mirco , Turano Ermanna , Budui Simona , Sbarbati Andrea , Krampera Mauro , Bonetti Bruno 
Published: August 2009

AbstractMesenchymal stem cells (MSCs) represent a promising therapeutic approach for neurological autoimmune diseases; previous studies have shown that treatment with bone marrow-derived MSCs induces immune modulation and reduces disease severity in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Here we show that intravenous administration of adipose-derived MSCs (ASCs) before disease onset significantly reduces the severity of EAE by immune modulation and decreases spinal cord inflammation and demyelination. ASCs preferentially home into lymphoid organs but also migrates inside the central nervous system (CNS). Most importantly, administration of ASCs in chronic established EAE significantly ameliorates the disease course and reduces both demyelination and axonal loss, and induces a Th2-type cytokine shift in T cells. Interestingly, a relevant subset of ASCs expresses activated α4 integrins and adheres to inflamed brain venules in intravital microscopy experiments. Bioluminescence imaging shows that α4 integrins control ASC accumulation in inflamed CNS. Importantly, we found that ASC cultures produce basic fibroblast growth factor, brain-derived growth factor, and platelet-derived growth factor-AB. Moreover, ASC infiltration within demyelinated areas is accompanied by increased number of endogenous oligodendrocyte progenitors. In conclusion, we show that ASCs have clear therapeutic potential by a bimodal mechanism, by suppressing the autoimmune response in early phases of disease as well as by inducing local neuroregeneration by endogenous progenitors in animals with established disease. Overall, our data suggest that ASCs represent a valuable tool for stem cell–based therapy in chronic inflammatory diseases of the CNS.
Multiplex parallel pair‐end‐ditag sequencing approaches in system biology
Authors: Ruan Yijun , Wei Chia‐Lin 
Published: August 2009

AbstractCharacterization of all the functional components constituted in human genome relies in our ability to completely elucidate the genetic/epigenetic regulatory networks, chromatin states, nuclear architectures, and genome variations. Such endeavors demand for the development of robust and effective genomic technologies. In the past few years, the availability of disruptive next generation DNA sequencing technologies has offered new promise for whole genome interrogation. However, despite the massive parallel and ultra‐high throughput capacity, the common nature of short read lengths found within these platforms limits their applications for many types of whole genome‐based analyses. To overcome such constrain, pair end ditag (PET) based sequencing concept was conceived as an immediate solution to expand the information content and extend the linear coverage. By sequencing paired end signatures from any desired DNA fragment and mapping them to the reference genome, PET strategy allows the accurate demarcation of target DNA boundaries and defines their locations on the genomic landscape. Furthermore, the ability to delineate relationship between two ends of a DNA molecule enables the full scale discovery of unconventional gene products, genome rearrangements, and chromatin interactions. Coupling with the massively parallel and ultra‐high throughput sequencing platforms, such unique features of PET strategy have the potential to revolutionize the approaches used to decipher regulatory networks in system biology, define the genome organizations, and characterize genome variations; which ultimately leads to the development of strategies for personalized medicine. Copyright © 2009 John Wiley & Sons, Inc.This article is categorized under:

Laboratory Methods and Technologies > Genetic/Genomic Methods
Thermodynamically based constraints for rate coefficients of large biochemical networks
Authors: Vlad Marcel O. , Ross John 
Published: August 2009

AbstractWegscheider cyclicity conditions are relationships among the rate coefficients of a complex reaction network, which ensure the compatibility of kinetic equations with the conditions for thermodynamic equilibrium. The detailed balance at equilibrium, that is the equilibration of forward and backward rates for each elementary reaction, leads to compatibility between the conditions of kinetic and thermodynamic equilibrium. Therefore, Wegscheider cyclicity conditions can be derived by eliminating the equilibrium concentrations from the conditions of detailed balance. We develop matrix algebra tools needed to carry out this elimination, reexamine an old derivation of the general form of Wegscheider cyclicity condition, and develop new derivations which lead to more compact and easier‐to‐use formulas. We derive scaling laws for the nonequilibrium rates of a complex reaction network, which include Wegscheider conditions as a particular case. The scaling laws for the rates are used for clarifying the kinetic and thermodynamic meaning of Wegscheider cyclicity conditions. Finally, we discuss different ways of using Wegscheider cyclicity conditions for kinetic computations in systems biology. Copyright © 2009 John Wiley & Sons, Inc.This article is categorized under:

Analytical and Computational Methods > Computational Methods
NH4[BAsO4F] – a New Layer Fluoro‐boroarsenate with a Silicate Related Topology
Authors: Lieb Alexandra , Weller Mark T. 
Published: August 2009

AbstractThe fluoro‐boroarsenate NH4[BAsO4F] has been obtained by the melt reaction of NH4H2AsO4, B(OH)3 and LiBF4. The dry reaction mixture, in a 3:3:2 ratio, was treated at 240 °C for 14 days. After cooling to room temperature and washing with hot water, the product was isolated as colourless crystals and powder. The crystal structure was determined by single‐crystal X‐ray diffraction. The structure consists of [BAsO4F]– layers, separated by ammonium ions, having a unique orientation pattern of the tetrahedra forming the constituent six‐membered rings. The topology of the fluoro‐boroarsenate layer is related to those of the silicate δ‐Na2Si2O5 and the borophosphate Mg(H2O)2[B2P2O8(OH)2]·H2O. NH4[BAsO4F] was further characterised by powder X‐ray diffraction, IR spectroscopy and EDX analyses.
Models of climate associations and distributions of amphibians in Italy
Authors: Girardello Marco , Griggio Matteo , Whittingham Mark J. , Rushton Stephen P. 
Published: August 2009

AbstractAnalyzing the relationships between the distribution of animal species and climatic variables is not only important for understanding which factors govern species distribution but also for improving our ability to predict future ecological responses to climate change. In the context of global climate change, amphibians are of particular interest because of their extreme sensitivity to the variation of temperature and precipitation regimes. We analyzed species–climate relationships for 17 amphibian species occurring in Italy using species distribution data at the 10 × 10 km resolution. A machine learning method, Random Forests, was used to model the distribution of amphibians in relation to a set of 18 climatic variables. The results showed that the variables which had the highest importance were those related to precipitation, indicating that precipitation is an important factor in determining amphibian distribution. Future projections showed a complex response of species distributions, emphasizing the potential severity of climate change on the distributions of amphibians in Italy. The species that will decrease the most are those occurring in mountainous and Mediterranean areas. Our results provide some preliminary information that could be useful for amphibian conservation, indicating if future conservation priorities for some species should be enhanced.
Use of a Nonionic Surfactant to Inhibit Precipitation of Anionic Surfactants by Calcium
Authors: Soontravanich Sukhwan , Scamehorn John F. 
Published: August 2009

AbstractPrecipitation of anionic surfactants by calcium ions has always been a major concern in formulations using anionic surfactants in hard water. In our previous work, it was found that the precipitation reaction was delayed when a mixture of anionic surfactants (sodium dodecyl sulfate and sodium octylbenzene sulfonate) was used at a certain mole ratio that would give the minimum in the difference in the supersaturation ratios between the two precipitating surfactants. In this work, the addition of nonylphenol ethoxylate (NP(EO)10) as a nonionic surfactant is shown to delay the onset of precipitation for a longer time. The zeta potential of precipitates reveals that the NP(EO)10 is able to slow down the precipitate growth by adsorbing onto the precipitate crystals and this results in larger mean particle size.