bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystallization, melting behavior, and morphology of PP/Novolac blends
Authors: Cui Limei , Zhang Yong , Zhang Yinxi 
Published: October 2006

AbstractThe crystallization, melting behavior, and morphology of Polypropylene (PP) and PP/Novolac blends were studied by scanning electron microscopy, wide angle X‐ray diffraction, differential scanning calorimetry, and polarized optical microscope. The results showed that the crystallization of PP in PP/Novolac blends was strongly influenced by crystallization temperature, particles size of Novolac, crosslinking, and compatibilizer maleic anhydride‐grafted PP. The Novolac resin could not only affect the crystal structure, but also acted as effective nucleating agents, accelerating the crystallization of PP in the PP/Novolac blends. And the smaller the Novolac particles were, the more effective were the nucleating agent for PP crystallization. Avrami equation was used to analyze the isothermal crystallization kinetics of PP and PP/Novolac blends. The influences of curing and compatibilizer on the crystallization behavior of PP were rather complicated. The crystallization thermodynamics were estimated using the Hoffman theory. The incorporation of cured Novolac and compatibilizer evidently decreased the chain folding energy of PP. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3288–3303, 2006
Stability of Thin Plasma Polymer Films Applied on Coil Coatings
Authors: Serra Ricardo , Zheludkevich Mikhail L. , Ferreira Mário G. S. 
Published: October 2006

AbstractSummary: The present work is devoted to the investigation of the stability of thin plasma polymer films of silica‐based material, which were deposited on top of polyurethane coil coatings. Microwave plasma polymerization was used with different precursor mixtures in order to produce thin polymer layers. The effects of precursor gas composition and of pressure were analyzed from the standpoint of the immersion stability of the plasma‐deposited polymer films. The results we obtained demonstrate a strong dependence of the immersion resistance on the gas precursor composition and pressure. Decrease of the operating pressure and of the oxygen concentration in precursor mixtures leads to the formation of more compact layers with a higher stability. Introduction of a fluorine‐containing component in the precursor mixtures also increases the stability of the plasma‐deposited polymer coatings.The SEM surface micrograph of a MW plasma polymer layer prepared using HMDSO/O2 gas mixture at 0.05 mbar.magnified imageThe SEM surface micrograph of a MW plasma polymer layer prepared using HMDSO/O2 gas mixture at 0.05 mbar.
Atomic Oxygen Production and Exploration of Reaction Mechanisms in a He‐O2 Atmospheric Pressure Glow Discharge Torch
Authors: Léveillé Valérie , Coulombe Sylvain 
Published: October 2006

AbstractSummary: This article reports on the performance of a miniature APGD‐t conceived for the production of reactive species participating in bio‐applications. Two operating parameters were varied: the plasma‐forming gas flow rate (0.5–1.5 slm He) and the flow rate of O2 (0–50 sccm), which was injected downstream from the plasma‐forming zone, and which was used as a source of reactive species. The production of reactive species (O) was optimized, and the air entrainment in the plasma jet was minimized for a He gas flow rate of 1–1.5 slm and an O2/He volumetric ratio of 0.3 vol.‐%. A survey of the possible reaction pathways in the afterglow plasma jet suggests that the reactive species present in the plasma afterglow, and possibly reaching a remote substrate, are metastable He(23S), ground state O, OH, O2 (a1Δg), O2 (b1Σg+), N, N2, N and O3.APGD‐t jet impinging on a finger.magnified imageAPGD‐t jet impinging on a finger.
Evaluating Missile Fuels
Authors: Osmont Antoine , Gökalp Iskender , Catoire Laurent 
Published: October 2006

AbstractThis paper presents simple and relatively efficient methods to estimate some physical and chemical properties of polycyclic alkanes. These properties are melting point, normal boiling point, standard enthalpy of vaporization at 298 K, standard enthalpy of formation at 298 K, standard enthalpy of combustion at 298 K, density (specific gravity) and flash point. These methods are validated, despite the scarcity of experimental data, with several tens of polycyclic alkanes. Then the methods are used to estimate properties of some polycyclic alkanes, which are currently in use as missile fuels: JP‐10, RJ‐4 and RJ‐5. Estimates and experimental data are found in good agreement for these fuels. This methodology is then used to evaluate missile fuel candidates to be used pure or as additive to JP‐10 or to blends such as RJ‐6. Several compounds are probably of interest for this task and their advantages and drawbacks are discussed.
Low Risk Synthesis of Energetic Poly(3‐Azidomethyl‐3‐Methyl Oxetane) from Tosylated Precursors
Authors: Barbieri Ugo , Polacco Giovanni , Paesano Emanuele , Massimi Roberto 
Published: October 2006

AbstractAzidated oxetanic polymers such as poly(3‐azidomethyl‐3‐methyl oxetane), are under investigation as “energetic” binder to be used as an alternative to polybutadiene in solid rocket propellants. The classic synthetic route for the production of the polymer is through an azidated monomer where the N3− functionality has been previously introduced by nucleophilic displacement of a suitable, usually a halogen, leaving group. However, this could involve critical steps with manipulation of a highly unstable liquid monomer. Here it is shown that the azidation can be performed as the final step of the preparation by substitution of the tosyl group in a preformed polymer. The procedure assures good yield and purity of the product and satisfactory rate of reaction, being the energetic functionality always kept in a safe form, which shows low shock and friction sensitivity. Poly(3‐azidomethyl‐3‐methyl oxetane) was prepared by azidation of poly(3‐tosyloxymethyl‐3‐methyl oxetane) in dimethylsulfoxide, testing several operating conditions. Moreover, hypothesizing a second order kinetics, the rate constant and the activation energy for the azidation step have been estimated.
Control of Structural Refinement and Composition in Al‐MoO3 Nanocomposites Prepared by Arrested Reactive Milling
Authors: Umbrajkar Swati M. , Schoenitz Mirko , Dreizin Edward L. 
Published: October 2006

AbstractAl‐MoO3 nanocomposites were synthesized by arrested reactive milling (ARM) using powders of Al and MoO3 as starting materials. Varying milling parameters lead to different scales of structural refinement in the nanocomposites. The objective of this work was to determine the range in which the degree of structural refinement can be changed in a controlled manner. The effect of structural refinement on the characteristics of these reactive nanocomposites was further investigated. The milling intensity was controlled by using different milling media along with varying amounts of process control agent (PCA). X‐Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC) and wire‐ignition tests were performed to analyze the Al‐MoO3 nanocomposites. Results indicate that the crystallite size decreased with increase in the milling intensity. However, increase in milling intensity also results in undesirable partial reaction between starting materials. Milling conditions resulting in the highest structural refinement and minimized partial reaction were identified. It was found that materials synthesized under the identified optimum conditions ignited at lowest temperature.
On the architecture and form of flexible process support
Authors: Snowdon R. A. , Warboys B. C. , Greenwood R. M. , Holland C. P. , Kawalek P. J. , Shaw D. R. 
Published: October 2006

AbstractThe ability of businesses to develop is frequently hampered by difficulties in changing underlying software systems. An example is the need to change when business partnerships are formed, or dissolved. This article is concerned with the architecture of business process support systems in the context of change, and particularly with the need for such systems to facilitate software change. The viable system model (VSM) is a cybernetic model of organisations that change. It provides an inclusive architecture in which both operational and development components are described within an organisation. This article illustrates, through a business supply chain example, the use of the VSM as an architecture for flexible process support systems. This architecture is systemic and inclusive: it incorporates the ongoing development of both the business and its underlying software. Copyright © 2006 John Wiley & Sons, Ltd.
SPARSE PARTITION REGULARITY
Authors: LEADER IMRE , RUSSELL PAUL A. 
Published: October 2006

Our aim in this paper is to prove Deuber's conjecture on sparse partition regularity, that for every $m$, $p$ and $c$ there exists a subset of the natural numbers whose $(m,p,c)$-sets have high girth and chromatic number. More precisely, we show that for any $m$, $p$, $c$, $k$ and $g$ there is a subset $S$ of the natural numbers that is sufficiently rich in $(m,p,c)$-sets that whenever $S$ is $k$-coloured there is a monochromatic $(m,p,c)$-set, yet is so sparse that its $(m,p,c)$-sets do not form any cycles of length less than $g$.Our main tools are some extensions of Nešetřil–Rödl amalgamation and a Ramsey theorem of Bergelson, Hindman and Leader. As a sideline, we obtain a Ramsey theorem for products of trees that may be of independent interest.
The systemic delivery and consumption of oxygen in the infant after cardiac surgery
Authors: Penny Daniel J. 
Published: October 2006

“All the vital mechanisms, however varied they may be, have only one object, that of preserving constant the conditions of life in the internal environment.”1An essential function of the cardiopulmonary system is to generate sufficient flow of oxygenated blood around the circulation in order to maintain normal cellular metabolism. The systemic delivery of oxygen is a function of the cardiac output and the content of oxygen in the systemic arterial blood, while the extent to which metabolising tissues require this oxygen for the maintenance of their integrity and function defines the systemic consumption of oxygen. As metabolising tissues have no mechanism for storing oxygen, they depend on its continuous supply, which must at least match their changing demands. As a result, it is a fundamental requirement of survival that the systemic consumption of oxygen, at all times, is matched by appropriate levels of its delivery.
Phytotransformation of 2,4‐Dinitrotoluene in Arabidopsis thaliana: Toxicity, Fate, and Gene Expression Studies in Vitro
Authors: Yoon Jong M. , Oliver David J. , Shanks Jacqueline V. 
Published: October 2006

AbstractBasic knowledge of the plant transformation pathways and toxicity of 2,4‐dinitrotoluene (2,4‐DNT) will assist in the design and assessment of a phytoremediation strategy. This study presents the toxicity and fate of 2,4‐DNT and gene expression in response to 2,4‐DNT exposure using the model plant Arabidopsis thaliana, an increasingly popular system for genetic and biochemical studies of phytotransformation of explosives. From the results of biomass and root growth assays for toxicity, 2,4‐DNT was toxic to the plants at concentrations as low as 1 mg/L. In the uptake study, 95% of the initial 2,4‐DNT was removed by 15‐day‐old seedlings from liquid media regardless of the initial 2,4‐DNT concentrations while 30% accounted for the adsorption to the autoclaved plant materials. The mass balance was over 86% using [U‐14C]2,4‐DNT, and the mineralization by the plants was less than 1% under sterile conditions during 14 days of exposure. The percentage of the bound radioactivity increased from 49% to 72% of the radioactivity in the plants, suggesting transformed products of 2,4‐DNT may be incorporated into plant tissues such as lignin and cellulose. Monoaminonitrotoluene isomers and unknown metabolites with short retention times were detected as transformed products of 2,4‐DNT by the plants. Most (68%) of the radioactivity taken up by the plants was in the root tissues in nonsterile hydroponic cultures. Glutathione and expression of related genes (GSH1 and GSH2) in plants exposed to 2,4‐DNT were 1.7‐fold increased compared to untreated plants. Genes of a glutathione S‐transferase and a cytochrome P450, which were induced by 2,4,6‐trinitrotoluene exposure in previous studies, were upregulated by 10‐ and 8‐fold, respectively. The application of phytoremediation and the development of transgenic plants for 2,4‐DNT may be based on TNT phytotransformation pathway characteristics because of the similar fate and gene expression in plants.
Chinese-scorpion (Buthus martensi Karsch) toxin BmK αIV, a novel modulator of sodium channels: from genomic organization to functional analysis
Authors: Chai Zhi-Fang , Zhu Mang-Mang , Bai Zhan-Tao , Liu Tong , Tan Miao , Pang Xue-Yan , Ji Yong-Hua 
Published: October 2006

In the present study, BmK αIV, a novel modulator of sodium channels, was cloned from venomous glands of the Chinese scorpion (Buthus martensi Karsch) and expressed successfully in Escherichia coli. The BmK αIV gene is composed of two exons separated by a 503 bp intron. The mature polypeptide contains 66 amino acids. BmK αIV has potent toxicity in mice and cockroaches. Surface-plasmon-resonance analysis found that BmK αIV could bind to both rat cerebrocortical synaptosomes and cockroach neuronal membranes, and shared similar binding sites on sodium channels with classical AaH II (α-mammal neurotoxin from the scorpion Androctonus australis Hector), BmK AS (β-like neurotoxin), BmK IT2 (the depressant insect-selective neurotoxin) and BmK abT (transitional neurotoxin), but not with BmK I (α-like neurotoxin). Two-electrode voltage clamp recordings on rNav1.2 channels expressed in Xenopus laevis oocytes revealed that BmK αIV increased the peak amplitude and prolonged the inactivation phase of Na+ currents. The structural and pharmacological properties compared with those of other scorpion α-toxins suggests that BmK αIV represents a novel subgroup or functional hybrid of α-toxins and might be an evolutionary intermediate neurotoxin for α-toxins.
Tankyrase recruitment to the lateral membrane in polarized epithelial cells: regulation by cell–cell contact and protein poly(ADP-ribosyl)ation
Authors: Yeh Tsung-Yin J. , Meyer Tobias N. , Schwesinger Catherine , Tsun Zhi-Yang , Lee Ray M. , Chi Nai-Wen 
Published: October 2006

PARsylation [poly(ADP-ribosyl)ation] of proteins is implicated in the regulation of diverse physiological processes. Tankyrase is a molecular scaffold with this catalytic activity and has been proposed as a regulator of vesicular trafficking on the basis, in part, of its Golgi localization in non-polarized cells. Little is known about tankyrase localization in polarized epithelial cells. Using MDCK (Madin–Darby canine kidney) cells as a model, we found that E-cadherin-mediated intercellular adhesion recruits tankyrase from the cytoplasm to the lateral membrane (including the tight junction), where it stably associates with detergent-insoluble structures. This recruitment is mostly completed within 8 h of calcium-induced formation of cell–cell contact. Conversely, when intercellular adhesion is disrupted by calcium deprivation, tankyrase returns from the lateral membrane to the cytoplasm and becomes more soluble in detergents. The PARsylating activity of tankyrase promotes its dissociation from the lateral membrane as well as its ubiquitination and proteasome-mediated degradation, resulting in an apparent protein half-life of ∼2 h. Inhibition of tankyrase autoPARsylation using H2O2-induced NAD+ depletion or PJ34 [N-(6-oxo-5,6-dihydrophenanthridin-2-yl)-N,N-dimethylacetamide hydrochloride] treatment results in tankyrase stabilization and accumulation at the lateral membrane. By contrast, stabilization through proteasome inhibition results in tankyrase accumulation in the cytoplasm. These data suggest that cell–cell contact promotes tankyrase association with the lateral membrane, whereas PARsylating activity promotes translocation to the cytosol, which is followed by ubiquitination and proteasome-mediated degradation. Since the lateral membrane is a sorting station that ensures domain-specific delivery of basolateral membrane proteins, the regulated tankyrase recruitment to this site is consistent with a role in polarized protein targeting in epithelial cells.
Mice deficient in Cu,Zn-superoxide dismutase are resistant to acetaminophen toxicity
Authors: Lei Xin Gen , Zhu Jian-Hong , McClung James P. , Aregullin Manuel , Roneker Carol A. 
Published: October 2006

Although antioxidants are used to treat an overdose of the analgaesic/antipyretic drug APAP (acetaminophen), roles of antioxidant enzymes in APAP-induced hepatotoxicity remain controversial. Our objective was to determine impacts of knockout of SOD1 (superoxide dismutase; Cu,Zn-SOD) alone or in combination with selenium-dependent GPX1 (glutathione peroxidase-1) on APAP-induced hepatotoxicity. All SOD1-null (SOD1−/−) and SOD1- and GPX1-double-knockout mice survived an intraperitoneal injection of 600 mg of APAP per kg of body mass, whereas 75% of WT (wild-type) and GPX1-null mice died within 20 h. Survival time of SOD1−/− mice injected with 1200 mg of APAP per kg of body mass was longer than that of the WT mice (934 compared with 315 min, P&lt;0.05). The APAP-treated SOD1−/− mice had less (P&lt;0.05) plasma ALT (alanine aminotransferase) activity increase and attenuated (P&lt;0.05) hepatic glutathione depletion than the WT mice. The protection conferred by SOD1 deletion was associated with a block of the APAP-mediated hepatic protein nitration and a 50% reduction (P&lt;0.05) in activity of a key APAP metabolism enzyme CYP2E1 (cytochrome P450 2E1) in liver. The SOD1 deletion also caused moderate shifts in the APAP metabolism profiles. In conclusion, deletion of SOD1 alone or in combination with GPX1 greatly enhanced mouse resistance to APAP overdose. Our results suggest a possible pro-oxidant role for the physiological level of SOD1 activity in APAP-mediated hepatotoxicity.
Atorvastatin interferes with activation of human CD4+ T cells via inhibition of small guanosine triphosphatase (GTPase) activity and caspase-independent apoptosis
Authors: Brinkkoetter P-T , Gottmann U , Schulte J , Van Der Woude F J , Braun C , Yard B A 
Published: October 2006

SummaryAlthough a beneficial effect of hydroxy-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, i.e. statins, on cell-mediated immunity has been suggested in vivo and in vitro, little is known about the molecular and biochemical events by which statins inhibit T cell proliferation. To address this question, we investigated the effects of atorvastatin (AT) on intracellular cytokine production, T cell activation markers, cell cycle progression and apoptosis in human CD4+ T cells. AT did not influence intracellular cytokine production after short-term stimulation of whole blood with phorbol myristate acetate (PMA)/ionomycin or superantigen (SEB). In contrast, AT influenced CD45RA to RO switching dose-dependently, as well as CD25 expression, and caused cell cycle arrest in the G1 phase after long-term T cell stimulation. This occurred in conjunction with a reduced expression of cyclin-dependent kinases 2 and 4 and p21wav1/cip1 and was paralleled by an increased protein expression of p27kip1. In addition to G1 arrest, increased apoptosis was observed in AT-treated cells. In line with this, the expression of Bcl-xl and pBad were decreased by AT. Apoptosis was independent of caspases 3 and 9 activation. The inhibitory effect of AT on T cell proliferation could be overcome by addition of mevalonic acid or geranylgeranyl pyrophosphate, but not by farnesyl pyrophosphate or squalen, suggesting reduced protein prenylation. Activation of Rho, Rac and Ras were strongly reduced in AT-treated T cells, suggesting that impaired geranylation of these molecules might underlie the inhibitory effect of AT on T cell proliferation.
The influence of previous exposure to environmental mycobacteria on the interferon-gamma response to bacille Calmette–Guérin vaccination in southern England and northern Malawi
Authors: Weir R E , Black G F , Nazareth B , Floyd S , Stenson S , Stanley C , Branson K , Sichali L , Chaguluka S D , Donovan L , Crampin A C , Fine P E M , Dockrell H M 
Published: October 2006

Summary
We report a large study of the effect of BCG vaccination on the in vitro 6-day whole blood interferon-gamma (IFN-γ) response to antigens from eight species of mycobacteria among schoolchildren in south-eastern England, where bacille Calmette–Guérin (BCG) vaccination is highly protective against pulmonary tuberculosis, and among young adults in northern Malawi, where BCG vaccination is not protective. In the UK children, BCG induced an appreciable increase in IFN-γ response to antigens from most species of mycobacteria. The degree of change was linked to the relatedness of the species to Mycobacterium bovis BCG, and provides further evidence of the cross-reactivity of mycobacterial species in priming of the immune system. IFN-γ responses to purified protein derivatives (PPDs) from M. tuberculosis and environmental mycobacteria were more prevalent in the Malawian than the UK group prior to vaccination; BCG vaccination increased the prevalence of responses to these PPDs in the UK group to a level similar to that in Malawi. There was no evidence that the vaccine-induced change in IFN-γ response was dependent upon the magnitude of the initial response of the individual to environmental mycobacteria in the United Kingdom or in Malawi. These observations should assist the development and interpretation of human clinical trials of new vaccines against M. tuberculosis in areas of both low and high exposure to environmental mycobacteria.
C-reactive protein is expressed and secreted by peripheral blood mononuclear cells
Authors: Haider D G , Leuchten N , Schaller G , Gouya G , Kolodjaschna J , Schmetterer L , Kapiotis S , Wolzt M 
Published: October 2006

SummaryC-reactive protein (CRP) protects against bacterial pathogens and is a predictor of cardiovascular events. CRP is produced by vascular and organ-specific cells but the generation of CRP from peripheral blood mononuclear cells (PBMC) is poorly established. In a randomized, double-blind, placebo-controlled, two-way cross-over trial six healthy volunteers received a bolus infusion of 20 IU/kg Escherichia coli endotoxin [lipopolysaccharide (LPS)] or placebo. Intracellular CRP protein and CRP secretion of peripheral blood mononuclear cells (PBMC) was measured at baseline and 6 h after LPS by flow cytometry and enzyme-linked immubosorbent assay (ELISA), respectively. CRP mRNA expression was determined by real-time polymerase chain reaction (PCR). Regulation of the expression pathway was assessed using specific inhibitors in vitro. Small amounts of CRP protein and mRNA were detectable in PBMC, which were up-regulated between two- and eightfold by endotoxaemia in vivo. Augmented expression and release of CRP by LPS was consistent in PBMC cell culture experiments. LPS, interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF)-α increased and IL-10 reduced CRP expression in PBMC. Toll-like receptor (TLR)-4, nuclear factor (NF)-κB and protein kinase C (PKC) activation were identified as intracellular signal transduction pathways of LPS-induced CRP expression. Constitutive CRP expression and release in PBMC is enhanced by inflammatory stimuli in vivo and in vitro. LPS might induce CRP generation via activation of TLR-4, NF-κB and PKC.