Autoantibody studies in juvenile rheumatoid arthritis

Early studies showed few immunologic abnormalities in juvenile rheumatoid arthritis (JRA) patients. There were no specific laboratory markers useful for diagnosis and assessment of the course of disease in JRA. Previous work showed an association of antinuclear antibodies (ANA) with early-onset pauciarticular disease and iridocyclitis. Similarly, the presence of 19S immunoglobulin (Ig) M rheumatoid factors (RF) was associated with late-onset polyarticular disease in girls. More recent studies have detected many unique autoantibodies. Newer assays show 19S IgM RF in up to 35% of JRA patients, although still mainly in girls with late-onset polyarticular disease. Hidden 19S IgM RF can be shown in up to 75% of JRA patients using different procedures, primarily in those with active polyarticular-or pauciarticular-onset disease. Immune complexes have been detected in JRA patients by means of different techniques; their presence usually correlates with active disease. Studies on a specific ANA in JRA have shown no common extractable nuclear antigen, but antihistone antibodies have been found in up to 75% of cases, again mainly in those with pauciarticular onset and iritis. Finally, a variety of unusual immunologic proteins have also been detected, including anti-ocular, anti-cellular, anti-cardiolipin, anti-perinuclear factor, and anti-collagen antibodies. This review evaluates the significance of these antibodies that can now be found in JRA.     

Receptor-mediated activation of multiple serine/threonine kinases in human leukocytes

Activation of the microbicidal response of phagocytes requires cytosolic ATP and is associated with extensive protein phosphorylation, suggesting the involvement of protein kinases in the signal transduction cascade. An in vitro renaturation assay was used to identify the protein kinase(s) activated by chemoattractants in human blood neutrophils. Four distinct kinases were activated by the chemotactic peptide formyl-methionyl-leucyl-phenyl-alanine with molecular masses of 72, 65, 49, and 41 kDa (designated PK72, PK65, PK49, and PK41, respectively). PK72 and PK65 were activated very rapidly (5-15 s), yet transiently. By comparison, PK49 and PK41 responded in a slower, more sustained manner. Treatment of extracts of activated cells with alkaline phosphatase reverted the stimulation of the kinases, suggesting that phosphorylation is the post-translational modification that underlies activation of the kinases. Stimulation of PK72 and PK65 by chemoattractant was independent of calcium and protein kinase C. In contrast, elevation of cytosolic free calcium levels was sufficient and appeared to be necessary for full activation of PK49 and PK41. While phorbol esters can mimic the effects of formyl-methionyl-leucyl-phenylalanine on PK49 and PK41, inhibition of protein kinase C by staurosporine did not prevent the receptor-mediated activation of these kinases. PK41 most likely corresponds to the Erk-1 isoform of mitogen-activated protein (MAP) kinase. Accordingly, PK41 effectively phosphorylated myelin basic protein, known to be a good substrate for Erk-1. The electrophoretic mobility of PK49 is similar to that of MAP kinase-kinase (MAP/Erk kinase). However, immunoprecipitation experiments indicated that PK49 is not MAP/Erk kinase. The identity of this and other kinases remains to be defined, but possible candidates are discussed. In addition to autophosphorylating, PK72, PK65, and PK41 were shown to effectively phosphorylate exogenous substrates. These kinases may therefore play a role in signal transduction during stimulation by chemoattractants.     

The Kuroshio variations from satellite-derived sea surface temperature and Argos satellite-tracking Lagrangian drifters

This study aimed to identify the spatial and temporal variations of the Kuroshio using satellite-derived Sea Surface Temperature (SST) data and a total of 585 Argos satellite-tracking Lagrangian drifters during 1987–2006 in the northwestern Pacific Ocean. The threshold of high surface velocity, more than 75 cm s^–1, was used to determine the location of the Kuroshio Current and found that its width ranged from 50 to 100 km. Moreover, this study first conducted a synoptic view for three predominant regions of the Kuroshio, including the area east of Taiwan, the area east of the East China Sea (ECS) and the area south of Japan. We found that the Kuroshio flows at a three-step increase in speed from upstream to downstream. The maximum mean surface velocity, 153 cm s^–1, occurred to the south of Japan. Furthermore, the higher surface velocity of the Kuroshio was usually during the summertime (from April to September). In addition, the four-cruise CTD (Conductivity, Temperature, Depth)-transect data observed in January 2005 were collected to identify and validate the path of the Kuroshio axes. The results showed that the measure of 17.5°C at a depth of 200 m could be regarded as an indicator of the Kuroshio axis, corresponding with the maximum surface velocities of the Argos drifters. The monthly satellite-derived SST values of the Kuroshio were usually more than 10°C, so it was difficult to find a specific isotherm to express the location of the Kuroshio. However, extensive Kuroshio fronts derived from satellite SST data were found in this study. These Kuroshio fronts, associated with high SST gradients, were usually located on the boundary between the warm water of the Kuroshio and the colder water of the shelf, corresponding with the boundary of high surface velocity of the Argos drifters. Consequently, this study suggests that these Kuroshio fronts can be regarded as an effective indicator of the Kuroshio paths and its main axes.     

Influences of thermal cycling and low-energy impact on the fatigue behavior of carbon/PEEK laminates

Effects of low-energy impact and cyclic thermal loading on fatigue behavior of carbon fiber reinforced polyetheretherketone (carbon/PEEK) laminates have been examined. The fatigue behavior of the virginal composites, low-energy impacted composites, and low-energy-impacted and thermally exposed composites were investigated. Cyclic thermal loading was performed in the temperature range between 60 and −60°C. Residual tensile strength was measured to aid in understanding the influence of low-energy impact on the retention of tensile strength. Fatigue testing involved a stress ratio of 0.1, with a frequency of 3 Hz. The Weibull distribution function was used to evaluate the ultimate tensile strength and fatigue life. S–N curves were plotted and the influence of thermal cycling and the low-energy impact on the fatigue sensitivity of the carbon/PEEK laminates was investigated. Stiffness variation during fatigue testing was monitored and differences in stiffness reduction for three test conditions were compared. C-scan was used to investigate the damage zone under different low-energy impacts and to understand damage propagation during fatigue testing. Moreover, scanning electron microscopy (SEM) was used to examine the fracture morphologies of carbon/PEEK composites in both tensile failure and fatigue failure conditions.     

A novel approach to the formation of amorphous carbon nitride film on silicon by ECR-CVD

Amorphous carbon nitride films have been synthesized on silicon by using an ECR-CVD system equipped with a DC bias and a mixture of C₂H₂, N₂ and Ar. Excess argon together with the application of DC bias can increase the ratio of nitrogen to carbon in the film up to 41% as determined by XPS. FTIR spectrum shows an absorption band between 1000 and 1700 cm⁻¹ which proves the incorporation of nitrogen atoms into the amorphous network of carbon. The plasma chemistry of the system was also analyzed by OES to investigate the active chemical species that were involved in the formation of carbon nitride. The result indicated that the addition of excess argon (four times more than nitrogen) can effectively enrich the excited-state CN radicals which subsequently promotes the concentration of nitrogen in the amorphous carbon nitride film. This observation is likely due to the lower ionization energy of argon (15.8 eV), argon's larger cross-section area for collision and its massive weight in comparison with the indispensable hydrogen gas as employed in the synthesis of other related materials.     

A trip-based multicasting model in wormhole-routed networks withvirtual channels

This paper focuses on efficient multicasting in wormhole-routed networks. A trip-based model is proposed to support adaptive, distributed, and deadlock-free multiple multicast on any network with arbitrary topology using at most two virtual channels per physical channel. This model significantly generalizes the path-based model proposed earlier which works only for Hamiltonian networks and cannot be applicable to networks with arbitrary topology resulted due to system faults. Fundamentals of the trip-based model, including the necessary and sufficient condition to be deadlock-free, and the use of appropriate number of virtual channels to avoid deadlock are investigated. The potential of this model is illustrated by applying it to hypercubes with faulty nodes. Simulation results indicate that the proposed model can implement multiple multicast on faulty hypercubes with negligible performance degradation     

Mining multilevel and location-aware service patterns in mobile web environments

In this correspondence, we address the issue of efficiently mining multilevel and location-aware associated service patterns in a mobile web environment. In terms of multilevel concept, we consider the complex problem that locations and services are of hierarchical structures. We propose a new data mining method named two-dimensional multilevel (2-DML) association rules mining, which can efficiently discover the associated service request patterns by taking into account the multilevel properties of locations and services. The discovered patterns can be effectively utilized in real applications like location-based and personalized services. To the best of our knowledge, this is the first work addressing this research issue. Some variations of the 2-DML method with different properties in terms of execution efficiency and memory efficiency were also developed. Through empirical evaluation, the proposed methods are shown to deliver good performance in terms of efficiency and scalability under various system conditions.     

Controllable oxygen vacancies to enhance resistive switching performance in a ZrO2-based RRAM with embedded Mo layer

In this study, the resistive switching characteristics of a ZrO(2)-based memory film with an embedded Mo layer are investigated. The experimental results show that the forming process can be removed by inserting an embedded Mo metal layer within ZrO(2) via a post-annealing process. The excellent memory performance, which includes lower operation voltage (<1.5 V), good endurance (>10(3) cycles), a stubborn nondestructive readout property (>10(4) s), and long retention time (>10(7) s), is also demonstrated. Moreover, high-speed operation (10 ns) can be successively maintained over 10(3) cycles without any operational errors observed in this memory device. Due to the interface layer induced by the Ti top electrode, the formation and rupture of conducting filaments are suggested to occur near the Ti/ZrO(2) interface. The oxygen vacancies induced by the embedded Mo can enhance the formation of conducting filaments and further improve the switching characteristics in ZrO(2)-based devices.     

Functionalized polymer spheres via one-step photoinduced synthesis for antimicrobial activity and gene delivery

Despite the fact that polystyrene (PS) spheres have been developed as polymeric carriers or matrices for various biomedical applications, the synthesis of PS spheres is time-consuming. This work describes the fabrication of a uniform PS sphere, coated with silver nanoparticles (Ag-PS), by simultaneous photoinduced polymerization and reduction fabricated using x-rays in aqueous solution without any initiator. The solution contains only styrene, silver ions (Ag(+)), and poly(vinyl pyrrolidone) (PVP) as a stabilizer. The proposed mechanism of the formation of the Ag-PS nanocomposite spheres involves the generation of radicals in the aqueous solution to induce PS polymerization and the reduction of Ag. The distribution of the sizes of the core PS spheres in the Ag-PS nanocomposite spheres was systematically examined as a function of irradiation time, concentration of styrene, and amount of PVP. Ag-PS nanocomposite spheres exhibit antimicrobial activity against bacteria (Escherichia coli and Staphylococcus aureus). Additionally, the cationic (vinylbenzyl)trimethylammonium (TMA) monomer was photopolymerized to form positively charged TMA-PS spheres as gene carriers with uniquely low cytotoxicity. Given these design advantages, the method proposed herein is simpler than typical approaches for synthesizing PS spheres with functionalized groups and PS spheres coated with Ag nanoparticles.     

Comparison of type-I and type-II accelerated life tests forselecting the most reliable product

In product research and development, one might wish to select the most reliable of several highly-reliable competing products. Both type-I and type-II accelerated life tests (ALT) are well-known to estimate and compare the life of highly reliable (nonrepairable) products within a reasonable testing time. A common decision problem is to choose the better plan for achieving the above goal. This paper proposes an intuitive selection rule for each ALT plan, and then derives the respective optimal ALT sampling plan when the acceleration factor (AF) is known and unknown. Finally, some criteria of Mackay are used to compare the two plans. From a practical point of view, the type-II ALT sampling plan is more convenient, and needs smaller sample size than the type-I ALT sampling plan. Nevertheless, the latter has shorter mean duration time and life testing time than the former