bluuebunny/crossref_metadata_2025 huggingface dataset:
Mapping Natural Phenomena: Boreal Forest Fires with Non-discrete Boundaries
Authors: Remmel Tarmo K. , Perera Ajith H.
Published: January 2010

Forest fires are spatially and temporally frequent in the boreal forest biome and continue to alter the spatial mosaic of its forest cover. Some of these fires occur in remote locations where direct socio-economic impacts are negligible, and are therefore not suppressed. However, these natural fires have many ecological consequences, and their monitoring and mapping therefore pose both an important and a challenging task. The current state of the art for fire-event mapping in remote northern Ontario is conducted at variable cartographic scales and generally relies on recording the approximate perimeters of the burned area from fixed-wing aircraft or helicopters with a handheld global positioning system receiver. All such techniques treat forest-fire boundaries, regardless of their detection and mapping resolutions or of the irregularity and gradient-like characteristics of their burned/not-burned interface, as crisp lines. Here we describe a procedure for standardizing the mapping of forest fires by an approach using high-spatial-resolution IKONOS satellite imagery that considers the actuality of gradual boundaries by assessing the fire-membership strength of each pixel prior to developing a footprint describing an individual fire event. Our case study is from northern Ontario, Canada, where the remote boreal forest fires are not regularly suppressed or monitored/mapped using traditional means. Furthermore, our analysis explores the sensitivity of this mapping effort to spatial resolution when describing measures of fire-footprint spatial geometry. We compare our mapping results with fire boundaries obtained by other means, using a series of overlap statistics to assess their spatial coincidence.
Theoretical study on the structure and energetics of intergranular glassy film in Si3N4-SiO2ceramics
Authors: Yoshiya Masato , Tanaka Isao , Adachi Hirohiko , Cannon Rowland M.
Published: January 2010

Molecular dynamics simulations have been performed to investigate intergranular glassy film in Si3N4–SiO2ceramics. A 90°-twist grain boundary was employed as a representative random grain boundary and an amorphous structure of the intergranular glassy film was introduced in the calculations. It is found that the presence of the intergranular glassy film at the grain boundary significantly decreases the number of dangling bonds at the interface originating from geometric strain due to misorientation of adjacent Si3N4grains. Calculations with a several of thicknesses of the intergranular glassy film revealed that the excess energy significantly decreased with the increase in the thickness smaller than 7.0Å, while further increase in the thickness did not contribute to a release in the geometric strain energy. Equilibrium thickness of the intergranular glassy film was estimated from the calculations. A new approach to estimating the equilibrium thickness is proposed. A possible explanation of the disparity between intergranular glassy film thicknesses of the intergranular glassy film measured by high-resolution electron microscopy and electron energy-loss spectroscopy is given in terms of ordering of atoms at the interface.
Spark plasma sintering of self-doped alumina powders
Authors: Suárez Marta , Fernández Adolfo , Torrecillas Ramón , Menéndez José Luis , García-Granda Santiago , Fauth Francois
Published: January 2010

This work explores the sintering by spark plasma sintering of self-doped submicrometre alumina powders following an alcoxide route. It is shown that the self-doping process leads to nucleation of alumina nanoparticles located in the surface of the initial alumina grains, therefore avoiding the presence of phases other than α-Al2O3in the final microstructure. The presence of such alumina nanocrystals leads to a modification of the sintering process minimizing grain growth compared to un-doped alumina powders under similar sintering conditions.
High density carbon materials obtained at relatively low temperature by spark plasma sintering of carbon nanofibers
Authors: Borrell Amparo , Fernández Adolfo , Merino César , Torrecillas Ramón
Published: January 2010

Graphitic materials obtained at low temperatures are interesting for a wide range of industrial applications including bipolar plates. In this work, graphite based nanocomposites have been obtained starting from carbon nanofibers and a mixture of carbon nanofibers with 20 vol.% of alumina nanopowders. High density carbon components were obtained by using Spark Plasma Sintering at temperatures as low as 1500–1800°C for this kind of materials. The effect of spark plasma sintering parameters on the final density, and the mechanical and electrical properties of resulting nanocomposites have been investigated. Pure carbon nanofibers with around 90 % of theoretical density and fracture strength of 60 MPa have been obtained at temperatures as low as 1500°C applying a pressure of 80 MPa during sintering. It has been proved that attrition milling is a suitable method for preparing homogeneous mixtures of carbon nanofibers and alumina powders.
Cu-Ni-YSZ anodes for solid oxide fuel cell by mechanical alloying processing
Authors: Restivo Thomaz A. Guisard , Mello-Castanho Sonia R. H.
Published: January 2010

The work shows some results concerning a new cermet material 40 vol.% [(Cu)–Ni]–YSZ processed by mechanical alloying followed by Sintering by Activated Surface method. The projected cermet microstructure for this application is expected to possess microstructural characteristics that lead to better electric and ionic percolating, higher electrocatalytic activity and fuel reforming. The powder samples prepared by mechanical alloying optimized conditions show a homogeneous mixture. Transmission and scanning electron microscope analysis have demonstrated the powder particles are nanosized after 2 h of milling, showing lamellar internal structure aggregates. Suitable sintered pellets are obtained from these powders, within the required porosity and microstructure. Sintering kinetics studies for pellets of Ni–YSZ and Ni–Cu–YSZ indicate 2-step sintering processes. Copper additive promotes sintering and refines the microstructure.
Rapid transient-liquid-phase bonding of Al2O3 with microdesigned Ni/Nb/Ni interlayers
Authors: Hong Sung M. , Reynolds Thomas B. , Bartlow Christopher C. , Glaeser Andreas M.
Published: January 2010

The vast majority of man-made devices contain joints between similar or dissimilar materials. Ideally, joining is fast, reliable, and inexpensive. In this work we demonstrate that robust refractory joints between Al2O3 bodies can be produced rapidly and consistently by a transient-liquid-phase bonding process exploiting microengineered multilayer Ni/Nb/Ni interlayers. Samples were bonded for times ranging from 5 min to 6 h at 1400°C. Well-bonded assemblies were produced in all cases. Interlayers with remelt temperatures > 2200°C were achieved in as little as 5 min at 1400°C. In room-temperature bend tests, fractures initiated and propagated almost exclusively in the ceramic. Extension of this approach to other advanced ceramics should be possible, providing a rapid and reliable alternative to conventional joining approaches.
Van der Waals-London dispersion interaction framework for experimentally realistic carbon nanotube systems
Authors: Rajter Rick , French Roger H.
Published: January 2010

A system's van der Waals–London dispersion interactions are often ignored, poorly understood, or crudely approximated, despite their importance in determining the intrinsic properties and intermolecular forces present in a given system. There are several key barriers that contribute to this issue: 1) lack of the required full spectral optical properties, 2) lack of the proper geometrical formulation to give meaningful results, and 3) a perception that a full van der Waals–London dispersion calculation is somehow unwieldy or difficult to understand conceptually. However, the physical origin of the fundamental interactions for carbon nanotube systems can now be readily understood due to recent developments which have filled in the missing pieces and provided a complete conceptual framework. Specifically, our understanding is enhanced through a combination of a robust, ab-initio method to obtain optically anisotropic properties out to 30 electron Volts, proper extensions to the Lifshitz's formulations to include optical anisotropy with increasingly complex geometries, and a proper methodology for employing optical mixing rules to address multi-body and multi-component structures. Here we review this new framework to help end-users understand these interactions, with the goal of better system design and experimental prediction. Numerous examples are provided to show the impact of a material's intrinsic geometry, including optical anisotropy as a function of that geometry, and the effect of the size of the nanotube core and surfactant material present on its surface. We'll also introduce some new examples of how known trends in optical properties as a function of [n, m] can result in van der Waals interactions as a function of nanotube classification, radius, and other parameters. The concepts and framework presented are not limited to the nanotube community, and can be equally applied to other nanoscale or even biological systems.
A new method to measure monoclinic depth profile in zirconia-based ceramics from X-ray diffraction data
Authors: Gremillard Laurent , Grandjean Sylvie , Chevalier Jerome
Published: January 2010

In this paper a method to evaluate monoclinic fraction depth profile in zirconia, based on X-ray diffraction at grazing angles, is proposed. The necessary mathematical developments are exposed. The method is numerically tested in different theoretical configurations, and then on zirconia-toughened alumina and on alumina-toughened zirconia. The results show that it is possible to follow both surface fraction and thickness of the monoclinic layer, within the penetration depth of the X-rays. This is a considerable improvement over simple X-ray diffraction measurements. However, its accuracy is limited for high depth, but considerably improved as compared to previous methods.
Grain boundary plane distributions in aluminas evolving by normal and abnormal grain growth and displaying different complexions
Authors: Dillon Shen J. , Miller Herb , Harmer Martin P. , Rohrer Gregory S.
Published: January 2010

The grain boundary character distributions of selected doped aluminas were measured from normal and abnormal populations. The relative energies of the A-, C-, and R-planes of undoped alumina were also measured. There is an inverse relationship between the population of grain boundaries and the relative energies of grain boundary planes in undoped alumina. This relationship is found to be qualitative for abnormal grains, whose interfacial anisotropy may be affected by kinetic factors. It is found that the relative grain boundary anisotropy correlates with the temperature dependence of grain boundary complexion transitions in a particular system that is prone to abnormal grain growth. However, there is no direct correlation between the total anisotropy of the grain boundary character distribution and that system's propensity to undergo a particular complexion transition. Therefore, anisotropy will significantly affect the microstructural evolution in systems that are prone to abnormal grain growth, but the magnitude of anisotropy is not a sufficient selection criterion for determining which systems will undergo abnormal grain growth.
The role of interfaces in the behavior of magnetic tunnel junction structures
Authors: Petford-Long Amanda K.
Published: January 2010

Magnetic tunnel junctions are nanoscale oxide heterostructures that exhibit the phenomenon of tunnel magnetoresistance. The transport and magnetic behavior of these structures depends critically on parameters such as the layer thickness and the roughness and chemical abruptness of the interfaces between the layers, which are nanometer-scale in thickness. We have used high resolution electron microscopy, transmission electron microscopy chemical mapping and atom probe tomography to understand the microstructural origins of the magnetic and transport properties of magnetoresistive structures. We have also used in-situ transmission electron microscopy nanobiasing experiments to probe the local transport properties of magnetic tunnel junctions as a function of processing conditions.
Sintering of fully faceted crystalline particles
Authors: Klinger L. , Rabkin E.
Published: January 2010

A sintering process of two fully faceted particles of cubic or prismatic shape contacting each other along a grain boundary is considered. Analytic expressions for sintering kinetics are obtained under the assumption that the sintering process is controlled by self-diffusion along the facets and the grain boundary. It is shown that sintering kinetics are determined by the surface self-diffusion coefficient and exhibit only a weak dependence on the grain boundary diffusivity. The initial rate of sintering is time-independent, except for the case of two prismatic particles brought in contact along their edges, for which the time dependence of shrinkage is, under certain circumstances, similar to that for isotropic spherical particles. It is demonstrated that particle faceting slows down the sintering process.
The role of Si impurities in the transient dopant segregation and precipitation in yttrium-doped alumina
Authors: Šturm Sašo , Gülgün Mehmet A. , Richter Gunther , Morales Francisco M. , Cannon Rowland M. , Rühle Manfred
Published: January 2010

Y-doped alumina was sintered at 1500°C for 10 h under ultra-clean experimental conditions without experiencing any abnormal grain growth. The yttrium was fairly homogeneously distributed at the grain boundaries, with a mean value ofY= 5.5 at nm−2. The Y–Al–O precipitates in the clean, Y2O3-doped alumina specimen were the YAP (YAlO3) phase, whereas only the YAG (Y3Al5O12) phase was present in the Y2O3-doped alumina samples contaminated with SiO2. The excess concentrations of Y and Si atoms at the grain boundaries that, at the same time, provoke the formation of structurally complex YAG precipitates and abnormal grain growth were both estimated to be at 4–5 at nm−2. The compositions of the triple point pocket phases found in the region of the exaggeratedly grown alumina grains indicate the presence of alumino-silicate bulk liquids at the sintering temperature.
Kinetics and Mechanism of Carbamate Reaction of 4-Hydroxybenzyl Alcohol with Phenyl Isocyanate
Authors: Yang Pengfei , Li Tianduo , Li Junying , Zhu Xuwei , Xia Yongmei
Published: January 2010

The reaction of 4-hydroxybenzyl alcohol with phenyl isocyanate in 1,4-dioxane was investigated, using in-situ FT-IR as the main tool. It was found that there was a remarkable induction phase in the reaction. Further, the reaction between isocyanate and the two types of hydroxyl groups in 4-hydroxybenzyl alcohol falls into two phases, with the phenolic hydroxyl being unexpectedly more reactive than the alcoholic hydroxyl. The reaction kinetics were also studied, and the activation energies were calculated to be 46.4 kJ mol−1, 35.2 kJ mol−1 and 41.5 kJ mol−1 for the induction, phenolic and alcoholic phases, respectively.
The Photochemistry of Racemic and Optically Active 2-Iodooctane in Acetonitrile–Water Mixtures
Authors: Murphy Nicie Conley , Compton Robert N. , Pagni Richard M.
Published: January 2010

Racemic, optically active, and 2-deuterio-2-iodooctane were photolyzed in mixtures of acetonitrile (AN) and water ranging from 95% to 50% AN by volume. The major products in all cases were 1-, ( E)-2-, and ( Z)-2-octene. Minor products consisting of 2-, 3-, and 4-octanol and N-2-, N-3-, and N-4-(methylheptyl)acetamide were also formed in all cases. These products arise from the reaction of octyl cations with water and acetonitrile, with water being 4-5 times more reactive with the cations than acetonitrile. Octane was also formed in small yields, but no meso nor d,l 7, 8-dimethyltetradecane, as was seen in significant amounts in previously reported solvents. The behaviour of the 2-deuterio-2-iodooctane demonstrated that a small fraction of the reaction occurred through the 2-octyl carbene. The carbene was found to react with AN but not with water, an unusual result. Analysis of all these data showed that approximately 90% of the reaction occurred via the 2-octyl cation, 2-4% through the 2-octyl radical, and 4-6% through the 2-octyl carbene. F, the fraction of the intermediates going to product, was determined by examining the behaviour of optically active 2-iodoooctane in 95%, 90%, and 80% AN by volume. F goes up in value as the amount of water in the solvent increases, a result consistent with the photoreaction proceeding largely through ion pairs and free ions.
Kinetics of Photochemical Reactions under Restricted Geometry Conditions
Authors: Marchena M. , Sanchez F.
Published: January 2010

Kinetics of ground state reactions under restricted geometry conditions have been rationalized generally taking as a basis the Pseudophase Model, whose basic hypothesis is: The distribution of the reactants between the pseudophases is at equilibrium, that is, the rate of the reaction is slow in relation to the rates of entry and exit of the reactant to and from the receptor. However, photochemical reactions are generally very rapid, so the following question emerges: is the Pseudophase Model still applicable to photochemical reactions? To answer this question has been the primary objective of this work in which photochemical reactions in micelles, polymers and cyclodextrins have been reviewed. The lifetime of the fluorophore and the distributions of the quencher and the probe are crucial properties; they must be taken into account to obtain a proper description of the behaviour of a given system. The models of Infelta, Almgren and Quina visualise different scenarios with varied combinations of these properties. It is shown that, in some cases, the Pseudophase Model holds at least formally.
A Multilevel Model for Comorbid Outcomes: Obesity and Diabetes in the US
Authors: Congdon Peter
Published: January 2010

Multilevel models are overwhelmingly applied to single health outcomes, but when two or more health conditions are closely related, it is important that contextual variation in their joint prevalence (e.g., variations over different geographic settings) is considered. A multinomial multilevel logit regression approach for analysing joint prevalence is proposed here that includes subject level risk factors (e.g., age, race, education) while also taking account of geographic context. Data from a US population health survey (the 2007 Behavioral Risk Factor Surveillance System or BRFSS) are used to illustrate the method, with a six category multinomial outcome defined by diabetic status and weight category (obese, overweight, normal). The influence of geographic context is partly represented by known geographic variables (e.g., county poverty), and partly by a model for latent area influences. In particular, a shared latent variable (common factor) approach is proposed to measure the impact of unobserved area influences on joint weight and diabetes status, with the latent variable being spatially structured to reflect geographic clustering in risk.
Caloxanthones O and P: Two New Prenylated Xanthones from Calophyllum inophyllum
Authors: Dai Hao-Fu , Zeng Yan-Bo , Xiao Qi , Han Zhuang , Zhao You-Xing , Mei Wen-Li
Published: January 2010

Chemical investigation of the EtOH extract of the twigs of Calophyllum inophyllum collected in Hainan Province of China resulted in the isolation of two new prenylated xanthones, caloxanthone O (1) and caloxanthone P (2). Their structures were elucidated by a study of their physical and spectral data. Compound 1 exhibited cytotoxicity against human gastric cancer cell line (SGC-7901),with an IC50 value of 22.4 μg mL-1.
Detection of HIV cDNA Point Mutations with Rolling-Circle Amplification Arrays
Authors: Wu Lingwei , Liu Quanjun , Wu Zhongwei , Lu Zuhong
Published: January 2010

In this paper we describe an isothermal rolling-circle amplification (RCA) protocol to detect gene point mutations on chips. The method is based on an allele-specific oligonucleotide circularization mediated by a special DNA ligase. The probe is circularized when perfect complementary sequences between the probe oligonucleotide and HIV cDNA gene. Mismatches around the ligation site can prevent probe circularization. The circularized probe (C-probe) can be amplified by rolling circle amplification to generate multimeric singlestranded DNA (ssDNA) under isothermal conditions. There are four sequence regions to bind respectively with fluorescent probe, RCA primer, solid probe and HIV cDNA template in the C-probe which we designed. These ssDNA products are hybridized with fluorescent probes and solid probes which are immobilized on a glass slide composing a regular microarray pattern. The fluorescence signals can be monitored by a scanner in the presence of HIV cDNA templates, whereas the probes cannot be circularized and signal of fluorescence cannot be found. The RCA array has capability of high-throughput detection of the point mutation and the single-nucleotide polymorphism (SNP).The development of C-probe-based technologies offers a promising prospect for situ detection, microarray, molecular diagnosis, single nucleotide polymorphism, and whole genome amplification.
Essential Oil Composition of Stems and Fruits of Caralluma europaea N.E.Br. (Apocynaceae)
Authors: Zito Pietro , Sajeva Maurizio , Bruno Maurizio , Maggio Antonella , Rosselli Sergio , Formisano Carmen , Senatore Felice
Published: January 2010

The essential oil of the stems and fruits of Caralluma europaea (Guss.) N.E.Br. (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analyzed. The analyses allowed the identification and quantification of 74 volatile compounds, of which 16 were aromatic and 58 non-aromatic. Stems and fruits contained 1.4% and 2.7% of aromatic compounds respectively, while non-aromatic were 88.3% and 88.8%. Non-aromatic hydrocarbons were the most abundant compounds in both organs, followed by fatty acids. Data showed differences in the profiles between stems and fruits which shared only eighteen compounds; stems accounted for 38 compounds while fruits for 53. Fruits showed a higher diversity especially in aromatic compounds with twelve versus four in stems. Among the volatiles identified in stems and fruits of C. europaea 26 are present in other taxa of Apocynaceae, 52 are semiochemicals for many insects, and 21 have antimicrobial activity. The possible ecological role of the volatiles found is briefly discussed.
Spectral Reflectance of Wheat Residue during Decomposition and Remotely Sensed Estimates of Residue Cover
Authors: Daughtry Craig S. T. , Serbin Guy , Reeves James B. , Doraiswamy Paul C. , Hunt Earle Raymond
Published: January 2010

Remotely sensed estimates of crop residue cover (fR) are required to assess the extent of conservation tillage over large areas; the impact of decay processes on estimates of residue cover is unknown. Changes in wheat straw composition and spectral reflectance were measured during the decay process and their impact on estimates of fR were assessed. Proportions of cellulose and hemicellulose declined, while lignin increased. Spectral features associated with cellulose diminished during decomposition. Narrow-band spectral residue indices robustly estimated fR, while broad-band indices were inconsistent. Advanced multi-spectral sensors or hyperspectral sensors are required to assess fR reliably over diverse agricultural landscapes.
Observation and Measurement of Negative Differential Resistance on PtSi Schottky Junctions on Porous Silicon
Authors: Banihashemian Seyedeh Maryam , Hajghassem Hassan , Erfanian Alireza , Aliahmadi Majidreza , Mohtashamifar Mansor , Mosakazemi Seyed Mohamadhosein
Published: January 2010

Nanosize porous Si is made by two step controlled etching of Si. The first etching step is carried on the Si surface and the second is performed after deposition of 75 Å of platinum on the formed surface. A platinum silicide structure with a size of less than 25 nm is formed on the porous Si surface, as measured with an Atomic Forced Microscope (AFM). Differential resistance curve as a function of voltage in 77 K and 100 K shows a negative differential resistance and indicates the effect of quantum tunneling. In general form, the ratio of maximum to minimum tunneling current (PVR) and the number of peaks in I-V curves reduces by increasing the temperature. However, due to accumulation of carriers behind the potential barrier and superposition of several peaks, it is observed that the PVR increases at 100 K and the maximum PVR at 100 K is 189.6.
Sustainable Non-Metallic Building Materials
Authors: Joseph Paul , Tretsiakova-McNally Svetlana
Published: January 2010

Buildings are the largest energy consumers and greenhouse gases emitters, both in the developed and developing countries. In continental Europe, the energy use in buildings alone is responsible for up to 50% of carbon dioxide emission. Urgent changes are, therefore, required relating to energy saving, emissions control, production and application of materials, use of renewable resources, and to recycling and reuse of building materials. In addition, the development of new eco-friendly building materials and practices is of prime importance owing to the growing environmental concerns. This review reflects the key tendencies in the sector of sustainable building materials of a non-metallic nature that have occurred over the past decade or so.
Analysis of Barriers and the Potential for Exploration of Deconstruction Techniques in Portuguese Construction Sites
Authors: Couto João , Couto Armanda
Published: January 2010

Deconstructing a building is the careful dismantling of that building so as to make possible the recovery of construction materials and components, promoting their reuse and recycling. However, deconstruction remains a rare procedure in Portugal. Using previous studies and data collected from present experiences, this paper presents a critical discussion on the importance of deconstruction for rehabilitation. Its aims are to discuss the main advantages, barriers and opportunities of this demolition technique, as well as the guidelines to the design process, aiming at assuring a successful management deconstruction process. Suggestions to impel this technique in Portugal are also described.
Loop Reactors
Authors: Middleton John C. , Carpenter Keith J.
Published: January 2010

The article contains sections titled:

1.

Description

2.

Fields of Application

2.1.

Liquid‐Phase Reactions

2.2.

Two‐Phase Reactions

3.

Practical Limitations

4.

Design Methods

4.1.

Experiments

4.2.

Residence‐Time Distribution
Change of synovial vascularity in a single finger joint assessed by power doppler sonography correlated with radiographic change in rheumatoid arthritis: Comparative study of a novel quantitative score with a semiquantitative score
Authors: Fukae Jun , Kon Yujiro , Henmi Mihoko , Sakamoto Fumihiko , Narita Akihiro , Shimizu Masato , Tanimura Kazuhide , Matsuhashi Megumi , Kamishima Tamotsu , Atsumi Tatsuya , Koike Takao
Published: January 2010

Objective

To investigate the relationship between synovial vascularity assessed by quantitative power Doppler sonography (PDS) and progression of structural bone damage in a single finger joint in patients with rheumatoid arthritis (RA).

Methods

We studied 190 metacarpophalangeal (MCP) joints and 190 proximal interphalangeal (PIP) joints of 19 patients with active RA who had initial treatment with disease‐modifying antirheumatic drugs (DMARDs). Patients were examined by clinical and laboratory assessments throughout the study. Hand and foot radiography was performed at baseline and the twentieth week. Magnetic resonance imaging (MRI) was performed at baseline. PDS was performed at baseline and the eighth week. Synovial vascularity was evaluated according to both quantitative and semiquantitative methods.

Results

Quantitative PDS was significantly correlated with the enhancement rate of MRI in each single finger joint. Comparing quantitative synovial vascularity and radiographic change in single MCP or PIP joints, the level of vascularity at baseline showed a significant positive correlation with radiographic progression at the twentieth week. The change of vascularity in response to DMARDs, defined as the percentage change in vascularity by the eighth week from baseline, was inversely correlated with radiographic progression in each MCP joint. The quantitative PDS method was more useful than the semiquantitative method for the evaluation of synovial vascularity in a single finger joint.

Conclusion

The change of synovial vascularity in a single finger joint determined by quantitative PDS could numerically predict its radiographic progression. Using vascularity as a guide to consider a therapeutic approach would have benefits for patients with active RA.
Functional impairment of the arterial wall in primary Sjögren's syndrome: Combined action of immunologic and inflammatory factors
Authors: Gerli Roberto , Vaudo Gaetano , Bocci Elena Bartoloni , Schillaci Giuseppe , Alunno Alessia , Luccioli Filippo , Hijazi Raed , Mannarino Elmo , Shoenfeld Yehuda
Published: January 2010

Objective

Primary Sjögren's syndrome (SS) shares clinical and serologic features with rheumatoid arthritis and systemic lupus erythematosus, 2 diseases characterized by acceleration of atherosclerosis. Signs of precocious atherosclerosis have also been shown in SS, although the pathogenic basis of early arterial damage is unclear. The arterial wall was functionally evaluated in SS subjects with analysis of the role played by disease‐related factors.

Methods

Endothelium‐dependent flow‐mediated vasodilation (FMV) and endothelium‐independent nitrate‐mediated vasodilation (NMV) were evaluated in 45 women with SS and 59 age‐matched female controls. In addition, serum soluble intercellular adhesion molecule 1, soluble vascular cell adhesion molecule 1 (VCAM‐1), and nitrotyrosine were detected.

Results

Although patient FMV values did not differ from those of control subjects (mean ± SD 7.4 ± 3.6 versus 7.7 ± 1.9; not significant), NMV was lower in SS patients than in controls (mean ± SD 8.1 ± 3.5 versus 10.3 ± 2.1; P ≤ 0.001). Patient NMV was inversely correlated with soluble VCAM‐1 levels (r = −0.38, P = 0.001) and directly correlated with leukocyte count (r = 0.26, P = 0.03). An NMV decrease was confirmed in SS patient subsets with evidence of leukopenia, rheumatoid factor, anti‐SSB antibodies, and joint involvement. However, patients with joint involvement or parotid enlargement, 2 of the sites mainly affected by chronic inflammation in SS, had an FMV lower than controls and patients without these clinical features.

Conclusion

Our results suggest that a functional impairment of the arterial wall may sustain early phases of atherosclerotic damage in SS. A combined effect of disease‐related chronic inflammatory and immunologic factors appears to support dysfunction of endothelium and vascular smooth muscle cells, respectively.
The Potential of Istanbul's Unprogrammed Public Spaces
Authors: Ertaş Hülya
Published: January 2010

Istanbul recreates itself constantly. A continually evolving city, it can be likened to a living organism. As Hülya Ertaş explains it owes much of its vibrancy and heterogeneity to its unprogrammed spaces. These create a blank canvas for the metropolis' citizens and their activities. They are also at the essence of the city's enviable diversity, as they provide important meeting places for a rich mix of social and ethnic groups. Copyright © 2010 John Wiley & Sons, Ltd.
Regioselective Reactions on a Chiral Substrate Controlled by the Configuration of a Chiral Catalyst
Authors: Kumar Raju Ranjith , Kagan Henri B.
Published: January 2010

A racemic mixture may be partially transformed in the presence of a chiral catalyst by kinetic resolution and formation of products with new structural features. If the starting material is fully consumed the products may still be enantiomerically enriched. The situation is summarized in the Introduction. A brief discussion on the regioselective transformations occurring on a racemic mixture under the influence of a chiral catalyst is presented in Section 2. Often stereo‐differences occur, each enantiomer of the starting material resulting in a different product. It allows one to predict what the behaviour of some enantiopure substrates should be in presence of each of the enantiomers of a chiral catalyst. Many examples are presented in Section 3. The chiral substrates under consideration have two different reacting sites, usually of the same nature (OH, CC, allylic positions, CH for carbene insertion, epoxide fragment, etc.). In some cases the absolute configuration of the catalyst allows an excellent control of the regioselectivity. This approach is promising for the selective transformation of chiral molecules.
Mass transport and thermodynamic analysis of PAHs in partitioning systems in the presence and absence of ultrasonication
Authors: Isaza Pedro A. , Daugulis Andrew J. , Karan Kunal
Published: January 2010

Transport of PAHs from Desmopan polymers to methanol under various mixing conditions and in the presence of ultrasound was analyzed. PAH transport was influenced by external transport resistances; however, agitation greater than 800 rpm yielded PAH transport completely limited by internal resistances. Delivery rates of phenanthrene, fluoranthene, and pyrene with ultrasonication were faster than that under any mixing condition, suggesting enhanced internal transport properties. Ultrasound also induced increased concentrations of PAHs in solution at equilibrium. The model developed described PAH delivery under sonicated/non‐sonicated conditions, while quantifying diffusive and thermodynamic properties. Diffusivities with and without ultrasound decreased with permeant molecular size agreeing with coefficients determined for similar aromatic compounds in polymers. Partitioning coefficients under sonicated and non‐sonicated conditions conclusively differed from each other and decreased as a function of PAH molecular size. Quantitative structure‐property relationship data of PAHs yielded factors predicting thermodynamic and transport behaviors, with polarizability being the best descriptor. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Flow of particles suspended in a sheared viscous fluid: Effects of finite inertia and inelastic collisions
Authors: Abbas Micheline , Climent Eric , Parmentier Jean‐François , Simonin Olivier
Published: January 2010

We investigate in this article the macroscopic behavior of sheared suspensions of spherical particles. The effects of the fluid inertia, the Brownian diffusion, and the gravity are neglected. We highlight the influence of the solid‐phase inertia on the macroscopic behavior of the suspension, considering moderate to high Stokes numbers. Typically, this study is concerned with solid particles O (100 μm) suspended in a gas with a concentration varying from 5% to 30%. A hard‐sphere collision model (with elastic or inelasic rebounds) coupled with the particle Lagrangian tracking is used to simulate the suspension dynamics in an unbounded periodic domain. We first consider the behavior of the suspension with perfect elastic collisions. The suspension properties reveal a strong dependence on the particle inertia and concentration. Increasing the Stokes number from 1 to 10 induces an enhancement of the particle agitation by three orders of magnitude and an evolution of the probability density function of the fluctuating velocity from a highly peaked (close to the Dirac function) to a Maxwellian shape. This sharp transition in the velocity distribution function is related to the time scale which controls the overall dynamics of the suspension flow. The particle relaxation (resp. collision) time scale dominates the particulate phase behavior in the weakly (resp. highly) agitated suspensions. The numerical results are compared with the prediction of two statistical models based on the kinetic theory for granular flows adapted to moderately inertial regimes. The suspensions have a Newtonian behavior when they are highly agitated similarly to rapid granular flows. However, the stress tensors are highly anisotropic in weakly agitated suspensions as a difference of normal stresses arises. Finally, we discuss the effect of energy dissipation due to inelastic collisions on the statistical quantities. We also tested the influence of a simple modeling of local hydrodynamic interactions during the collision by using a restitution coefficient which depends on the local impact velocities. © 2010 American Institute of Chemical Engineers AIChE J, 2010
A Phase II trial of the oral mTOR inhibitor everolimus in relapsed Hodgkin lymphoma
Authors: Johnston Patrick B. , Inwards David J. , Colgan Joseph P. , Laplant Betsy R. , Kabat Brian F. , Habermann Thomas M. , Micallef Ivana N. , Porrata Luis F. , Ansell Stephen M. , Reeder Craig B. , Roy Vivek , Witzig Thomas E.
Published: January 2010

Everolimus is an oral antineoplastic agent that targets the raptor mammalian target of rapamycin (mTORC1). The phosphatidylinositol 3‐kinase/mTOR signal transduction pathway has been demonstrated to be activated in tumor samples from patients with Hodgkin lymphoma (HL). The goal of this trial was to learn the antitumor activity and toxicity of everolimus in patients with relapsed/refractory HL. Patients were eligible if they had measurable disease, a platelet count >75,000, and an absolute neutrophil count >1,000. Patients received everolimus 10 mg PO daily. Dose reductions were allowed. Response was assessed after two and six cycles and then every three cycles until progression. Patients could remain on drug until progression or toxicity. Nineteen patients were enrolled. Median age was 37 years (range, 27–68). Patients had received a median of six prior therapies (range, 3–14) and 84% had undergone prior autologous stem cell transplant. The ORR was 47% (95% CI: 24–71%) with eight patients achieving a PR and one patient achieving a CR. The median TTP was 7.2 months. Four responders remained progression free at 12 months. Patients received a median of seven cycles of therapy. Of the 19 patients, one remains on therapy at 36 months; the others went off study because of progressive disease (16), toxicity (1), and death from infection (1). Four patients experienced a Grade 3 or higher pulmonary toxicity. Everolimus has single‐agent activity in relapsed/refractory HL and provides proof‐of‐concept that targeting the mTOR pathway in HL is clinically relevant. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
Immobilization of alcohol dehydrogenase on films prepared by the electrochemical copolymerization of pyrrole and 1‐(2‐carboxyethyl)pyrrole for ethanol sensing
Authors: Shimomura Masato , Kuwahara Takashi , Iizuka Kaede , Kinoshita Toshiki
Published: January 2010

The electrochemical copolymerization of pyrrole and 1‐(2‐carboxyethyl)pyrrole (Py‐COOH) was carried out, and a conducting polymer film with a Py‐COOH content of 5% and a conductivity of 6.6 × 10−4 S/cm was obtained. Alcohol dehydrogenase (ADH) was attached through amide linkage onto the surface of the conducting polymer film for the purpose of fabricating an ADH‐immobilized electrode applicable to the amperometric sensing of ethanol. The quantity and activity of the immobilized ADH were determined to be 400 μg/cm2 and 0.6 U/mg, respectively. With the ADH‐immobilized electrode, amperometric ethanol sensing was attempted in the presence of nicotinamide adenine dinucleotide (a cofactor of ADH) and Meldola's blue (an electron‐transferring mediator). The ADH‐immobilized electrode made the current response correspond to ethanol concentration, which reached 10 μA/cm2 at a concentration of 14 mM. The selectivity of the sensing was examined with alcohols other than ethanol. It was found that the ADH/copolymer electrode had a considerably larger current response to allyl alcohol. The selectivity was attributed to the specificity of native ADH with respect to the oxidation of alcohols. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Plasticization of poly(arylene ether nitrile) by the melt blending of phthalonitrile prepolymer: A rheological, mechanical, and thermal study
Authors: Zhong Jiachun , Jia Kun , Zhao Rui , Liu Xiaobo
Published: January 2010

Poly(arylene ether nitrile) (PEN)/phthalonitrile prepolymer (PNP) blends were prepared via a melt‐mixing process. The melt flow properties, compatibility, and thermal and mechanical properties were characterized by dynamic rheological testing, dynamic mechanical analysis, tensile testing, thermal analysis, and fracture surface morphology observation. The melt‐mixed PEN/PNP blends displayed excellent melt flow properties during processing. When the PNP content in PEN was increased, the viscosity of the blends decreased considerably. Compared with that of pure PEN, the dynamic complex viscosity of the PEN/PNP blend with an 11% addition of PNP dropped sharply from 7000 to 2000 Pa s at 350°C and a frequency of 10 Hz. The dynamic mechanical analysis and differential scanning calorimetry results showed good compatibility between PEN and PNP. Observations of the morphology of the fractured surfaces revealed better component dispersion in which PNP was dissolved in the PEN matrix. Importantly for further commercial applications, the blending materials maintained the characteristic thermal and thermooxidative stability and mechanical properties of PEN. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Flammability and mechanical properties of wood flour‐filled polypropylene composites
Authors: Bakar M. B. Abu , Ishak Z. A. Mohd , Taib R. Mat , Rozman H. D. , Jani S. Mohamad
Published: January 2010

Polypropylene (PP) composites filled with wood flour (WF) were prepared with a twin‐screw extruder and an injection‐molding machine. Three types of ecologically friendly flame retardants (FRs) based on ammonium polyphosphate were used to improve the FR properties of the composites. The flame retardancy of the PP/WF composites was characterized with thermogravimetric analysis (TGA), vertical burn testing (UL94‐V), and limiting oxygen index (LOI) measurements. The TGA data showed that all three types of FRs could enhance the thermal stability of the PP/WF/FR systems at high temperatures and effectively increase the char residue formation. The FRs could effectively reduce the flammability of the PP/WF/FR composites by achieving V‐0 UL94‐V classification. The increased LOI also showed that the flammability of the PP/WF/FR composites was reduced with the addition of FRs. The mechanical property study revealed that, with the incorporation of FRs, the tensile strength and flexural strength were decreased, but the tensile and flexural moduli were increased in all cases. The presence of maleic anhydride grafted polypropylene (MAPP) resulted in an improvement of the filler–matrix bonding between the WF/intumescent FR and PP, and this consequently enhanced the overall mechanical properties of the composites. Morphological studies carried out with scanning electron microscopy revealed clear evidence that the adhesion at the interfacial region was enhanced with the addition of MAPP to the PP/WF/FR composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and Biological Activity of Some 1,3‐Dihydro‐2H‐3‐benzazepin‐2‐ones with a Piperazine Moiety as Bradycardic Agents
Authors: Liang Hong‐Yu , Zhang Deng‐Qing , Yue Yun , Shi Zhe , Zhao Sheng‐Yin
Published: January 2010

A series of 1,3‐dihydro‐2H‐3‐benzazepin‐2‐ones with a piperazine moiety were designed and synthesized by treating the common intermediate of 1,3‐dihydro‐7,8‐dimethoxy‐3‐[3‐(1‐piperazinyl)propyl]‐2H‐3‐benzazepin‐2‐ones with a variety ofN‐aryl‐2‐chloroacetamides and acyl chlorides. Their structures have been characterized by1H‐NMR, MS, and elemental analysis. The title compounds were evaluated for their bradycardic activityin vitro. Most of the synthesized compounds exhibited some vasorelaxant activity and heart‐rate‐reducing activity with bradycardic potency.
Reactivity with dichotomous determinants of Ro 60 stratifies autoantibody responses in lupus and primary Sjögren's syndrome
Authors: Reed Joanne H. , Dudek Nadine L. , Osborne Shannon E. , Kaufman Kenneth M. , Jackson Michael W. , Purcell Anthony W. , Gordon Tom P.
Published: January 2010

Objective

Analysis of B cell determinants of Ro 60 exposed on the surface of apoptotic cells (apotopes) or intracellular epitopes provides insight into the structural forms of the autoantigen that break immune tolerance. This study was initiated to compare anti–Ro 60 responses in systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (SS) against membrane‐bound and intracellular forms of Ro 60.

Methods

The reactivity of autoantibodies from patients with SLE and primary SS to Ro 60 apotopes and epitopes was assessed by multiparameter flow cytometry and solid‐phase immunoassay. Anti–Ro 60 IgG was eluted from early apoptotic cells or recombinant Ro 60 immobilized on nitrocellulose, and binding to membrane‐bound and intracellular forms of Ro 60 was quantitated by flow cytometry.

Results

An immunodominant apotope, which was recognized by IgG from a subset of SLE patients with anti‐Ro, but not anti‐La, autoantibodies, was mapped to a region forming a helix‐loop‐helix at the apical tip of the Ro 60 molecule. Immobilization of this region to the solid phase exposed an epitope that was recognized by IgG from primary SS and SLE patients whose sera had both anti‐Ro and anti‐La autoantibodies. Autoantibodies eluted from either the surface of apoptotic cells or the Ro 60 epitope on the solid phase were non–cross‐reactive and specifically recognized membrane‐bound or cytoplasmic forms of Ro 60.

Conclusion

This is the first example of a dichotomy of human autoantibody responses against mutually exclusive determinants linked to a single domain of a systemic autoantigen and supports a model in which tolerance is broken by different immunogenic forms of Ro 60.
Iron(III) and Zinc(II) Calixarene Complexes: Synthesis, Structural Studies, and Use as Procatalysts for ε‐Caprolactone Polymerization
Authors: Arbaoui Abdessamad , Redshaw Carl , Elsegood Mark R. J. , Wright Victoria E. , Yoshizawa Akina , Yamato Takehiko
Published: January 2010

Treatment of the heterobimetallic iron(II) alkoxides [(THF)MFe(OtBu)3]2 with p‐tert‐butylcalix[4]areneH4 (L1H4) affords the oxo‐bridged diiron(III) complexes {Fe[M(NCMe)x]2L1}2(μ‐O), M=Na, x=2 1⋅8(CH3CN), M= K, x=3 2⋅3.5(CH3CN); similar use of p‐tert‐butylcalix[6]areneH6 (L2H6) afforded [{Fe2(μ‐O)Na2(OH2)(NCMe)2L2}2][{Fe2(μ‐O)Na(OH2)(NCMe)6L2}2]2−[Na(NCMe)5]22+ 3⋅9.46(CH3CN) and [{Fe2(μ‐O)L2(K(NCMe)2)2}2] 4⋅10.8(MeCN), respectively. In the case of 4, a minor product {(L22Fe8O8)[K(NCMe)1.5K(H2O)(NCMe)2.5]2} 5⋅6(CH3CN), which is comprised of chains of (L22Fe8O8) clusters bridged by K/MeCN fragments, is also isolated. Use of p‐tert‐butylcalix[8]areneH8 (L3H8) and two equivalents of [(THF)KFe(OtBu)3]2 affords [(K2(μ‐NCCH3)4(μ‐OH2))2(Fe2(μ‐O)L3H2)2(CH3CN)2] 6⋅9(CH3CN). In the case of p‐tert‐butyltetrahomodioxacalix[6]areneH6 (L4H6), reaction with [(THF)MFe(OtBu)3]2 (two equivalents) leads to isolation of the pseudoisomorphic complexes [M2(CH3CN)4L4Fe2(μ‐O)].4CH3CN M=Na 7⋅4(CH3CN), M=K 8⋅2(CH3CN); similar use of p‐tert‐butylhexahomotrioxacalix[3]areneH3 (L5H3) led to [Na2Fe2(μ‐OH)2(L5)2(CH3CN)4] 9⋅2(CH2Cl2). The complex [L4(ZnEt)4Zn2(CH3CN)4(μ‐OEt)2], 10⋅2(CH3CN), isolated from the reaction of L4H6 and ZnEt2 is also reported. Complexes 1–10 are structurally characterized (partially in the case of 4) and screened (not 5) as catalysts for the ring opening polymerization of ε‐caprolactone.