Induction of antitumor cytotoxic T lymphocytes with a MAGE-3-encoded synthetic peptide presented by human leukocytes antigen-A24

For the development of immunotherapy using MAGE peptides, the identification of additional tumor antigens is required. Because HLA-A24 is the most common allele in Japanese and is also frequently present in Caucasians, MAGE-3-encoded synthetic peptides with binding affinity for HLA-A24 were thus tested for the induction of specific CTLs from the peripheral blood mononuclear cells (PBMCs) of HLA-A24 healthy donors using a simplified method. By using a peptide with a sequence of IMPKAGLLI (amino acid position in MAGE-3 195-203), the CTL responses could thus be induced from unseparated PBMCs by stimulation with freshly isolated, peptide-pulsed PBMCs as antigen-presenting cells (APCs) and by also using interleukin 7 and keyhole limpet hemocyanin for a primary culture. The induced CTLs could lyse HLA-A24 carcinoma cells expressing MAGE-3, as well as the peptide-pulsed target cells, in an HLA class-I restricted manner. The identification of the MAGE-3/HLA-A24 peptide, IMPKAGLLI, may thus potentially offer the opportunities to design peptide-based immunotherapeutic approaches that might prove to be effective in treating patients with MAGE-3-positive malignant tumors.     

Tribological and structural characterization of a physical vapour deposited TiC/Ti(C,N)/TiN multilayer

A physical vapour deposited TiC/Ti(C,N)/TiN multilayer was investigated and compared with a PVD TiN monolayer coating in a ball-on-disc test. Wear and friction against a corundum ball were measured as a function of time and sliding velocity. In these experiments, the coefficient of friction remained constant at 0.2 as long as the ball was sliding on TiC or intermidiate Ti(C,N) layers. When the TiN layer was reached, the coefficient of friction became unstable and rose to an average value of 1–1.5, which is characteristic for a TiN/Al₂O₃ contact. Wear rates for the multilayer were found to be three to four times smaller as compared to the reference TiN. The multilayer morphology of the TiC/Ti(C,N)/TiN was revealed in a low-angle cross-section resulting from a prolonged ball-on-disc test. In that way, it was shown that the multilayer consisted of nine separate sublayers.     

Biodegradation of agricultural herbicides in sequencing batch reactors under aerobic or anaerobic conditions

This study investigated the biodegradability of the herbicides isoproturon and 2,4-dichlorophenoxyacetic acid (2,4-D) in sequencing batch reactors (SBRs). Two laboratory-scale (2L liquid volume) SBRs were employed: one reactor performing under aerobic and the other under anaerobic conditions. The aerobic SBR was operated at an ambient temperature (22+/-2 degrees C), while the anaerobic SBR was run in the lower mesophilic range (30+/-2 degrees C). Each bioreactor was seeded with a 3:1 mixture (by weight) of fresh sludge and biomass that had been previously exposed to both herbicides. The effect of herbicide concentration on either treatment process was explored at a hydraulic retention time (HRT) of 48 h, using glucose as a supplemental carbon substrate. Although no isoproturon degradation was observed in either system during the study, complete 2,4-D removal occurred after an acclimation period of approximately 30 d (aerobic SBR) and 70 d (anaerobic SBR). The aerobic reactor achieved complete 2,4-D utilization at feed concentrations up to 500 mg/L. A further increase to 700 mg/L, however, proved to be inhibitory since 2,4-D biodegradation was negligible. On the other hand, the anaerobic SBR was able to degrade 120 mg/L of 2,4-D, which corresponds to 40% of the maximum feed concentration applied. Moreover, glucose was consumed first throughout the experiment in a sequential utilization pattern relating to 2,4-D, with biodegradation of both substrates following closely first-order kinetics.     

Influence of Deposition Conditions on the Crystal Structure of MoS2 Coating

MoS2 coatings were prepared using an unbalanced bipolar pulsed DC （direct current） magnetron sputtering apparatus under different targets, cathode current densities, power modes and bias voltages. The morphology, structure and growth characteristics of MoS2 coatings were observed and identified respectively by scanning electron microscopy, X-ray diffractometry and mass spectrometry. The results show that MoS2 coatings evolve with the （002） basal plane parallel to the surface by using cold pressed target with lower density, lower cathodic current density, bipolar pulse DC power and minus bias voltage, whereas the coatings deposited under hot pressed target, higher cathodic current density, simple DC power and positive bias voltage have the （002） basal plane perpendicular to the surface. The influence of deposition conditions on the crystal structure of MoS2 coating is implemented by altering its growth rate and the energy of sputtering-deposition particles.     

Tribocorrosion behaviour of Ni–SiC nano-structured composite coatings obtained by electrodeposition

The combined corrosion-wear degradation of nano-structured Ni–SiC coatings in sliding contacts immersed in electrically conductive solutions is investigated in situ by electrochemical techniques (open-circuit potential measurements, E_OC, the potentiodynamic polarization measurements, PD, and the electrochemical impedance spectroscopy). The coating thickness was 50 μm, with an average volume of dispersed phases inside nickel of 20%. The samples were tested in a cell, containing the electrolyte and electrodes, and mounted on a pin-on-disk tribometer, with the working surface of the specimen facing upwards. Both continuous and intermittent friction tests were carried out. In the intermittent tests, friction was applied periodically: during each cycle, friction was first applied for 2 s at constant sliding speed under constant normal load and then stopped during a latency time of 20 s or 0.5 s. Without friction, the free potential reaches a passive value after immersion in the test solution. When friction force is applied the free potential is shutting down to active values. Under friction the measured current, I can be considered as the sum of two partial currents: one generated by the wear track areas, where the passive film is destroyed and the surface is active; the other one linked to the surface not subjected to friction and that remains in the passive state. A localised corrosion process when subjected to friction in 0.5 M K₂SO₄ was not observed on nano-structured Ni–SiC composite coatings. The mechanical destruction of the passive film occurs in the wear track by friction and subsequent restoration of the film (repassivation) when friction stops. The wear volume loss increases with sliding forces.     

A methodology for the assessment of the tribocorrosion of passivating metallic materials

The synergism between mechanical friction and corrosion may lead to an acceleration of the degradation of materials in sliding contacts exposed to the environment. Electrochemical measurements and sliding tests are proposed as a protocol suitable to decouple the material losses originating from the active material and the passive film, and to identify their electrochemical or mechanical nature. The corrosion resistance of a material, its ability to react onto chemical or mechanical attack, its susceptibility to tribocorrosion and the effect of a passive surface film on the coefficient of friction are evaluated. The proposed tribo‐electrochemical protocol allows to evaluate the potential and risks of applying newly developed materials in sliding contacts, and to support the selection and implementation of materials in industry in applications where corrosion and wear are potential degradation processes. This protocol extends the existing Standard Guide ASTM G 119‐04 ‘Determining Synergism between wear and Corrosion’ for passivating metallic materials. Copyright © 2009 John Wiley & Sons, Ltd.     

Different start-up strategies to enhance biohydrogen production from cheese whey in UASB reactors

The effect of different operational strategies and inoculum structure (granules and disaggregated granules) during the start-up of four up-flow anaerobic sludge blanket hydrogenogenic reactors was investigated. The more stable volumetric hydrogen production rates obtained were 0.38 and 0.36 L H₂/L-d, in reactors operated with a constant organic loading rate (OLR) with both inoculum structures, whereas in reactors operated with an increasing OLR methane started to be produced earliest in time. Specific hydrogenogenic activity results proved that the disaggregated inoculum produced a more active biomass than the granular one, but not granule formation was evident. The methane hydrogenotrophic activity was the main limitation of the systems evaluated. In the reactors inoculated with disaggregated sludge the start-up strategy did not influence the bacterial DGGE fingerprint, in contrast to the reactors started-up with granular sludge; members of the Clostridium genus were always present. The results demonstrated that operational conditions during the start-up period are crucial for the production of hydrogenogenic biomass.     

Effect of nanostructuring and Al alloying on friction and wear behaviour of thermal sprayed WC–Co coatings

Nanostructured WC–Co and WC–Co–Al coatings, with about 300-μm as-deposited coating thickness, were deposited by high velocity oxy-fuel (HVOF) spraying. Agglomerated nanostructured cermet powders produced by the Mechanomade® process was used for HVOF spraying. Dense and well-adherent coatings with crystal sizes below 30 nm were deposited on stainless steel 304 substrate. Porosity was less than 5% and the bond strength with the substrate was around 60 MPa. Experimental data on friction, wear, and abrasion resistance revealed that nanostructured WC–Co based coatings containing some Al as alloying element, exhibit improved tribological characteristics in comparison to nanostructured and micron-sized WC–Co coatings. This was attributed to a carbide particle distribution within the coating revealed by SEM, the absence of brittle W₂C-like phases revealed by XRD, and the presence of Al at particle/matrix boundaries revealed by TEM.     

Structure and mechanical properties of W-Se-C/diamond-like carbon and W-Se/diamond-like carbon bi-layer coatings prepared by pulsed laser deposition

Bi-layer W-Se-C/diamond-like carbon (DLC) and WSe_x/DLC coatings were obtained by standard and shadow-masked pulsed laser co-deposition from WSe₂ and graphite targets. W-Se-C coatings appeared as nanocomposites containing quasi-amorphous WSe₂, WC, spherical β-W nanocrystalline particles encapsulated in WSe₂ amorphous shell, and amorphous carbon phases. In WSe_x/DLC coatings, the formation of chemical bonds between W and C atoms was noticed at the interface. An increase of the C concentration over 40 at.% increases hardness and elasticity (up to 2 times at ~ 60 at.%C), and the Se/W ratio was always close to 1.4. The use of shadow-masked configuration avoids the deposition of micro- and nanoparticles. However, this method leads to a substantial increase of the Se content (Se/W ≥ 4), and the coatings became softer.     

A spatial and temporal analysis of child pedestrian crashes in Santiago,Chile

This paper presents a spatial and temporal analysis of child pedestrian crash data in Santiago, Chile during the period 2000–2008. First, this study identified seven critical areas with high child pedestrian crash risk employing kernel density estimation, and subsequently, statistically significant clusters of the main attributes associated to these crashes in each critical area were determined in a geographic information systems environment. Moran's I index test identified a positive spatial autocorrelation on crash contributing factors, time of day, straight road sections and intersections, and roads without traffic signs within the critical areas during the studied period, whereas a random spatial pattern was identified for crashes related to the age attribute. No statistical significance in the spatial relationship was obtained in child pedestrian crashes with respect to gender, weekday, and month of the year. The results from this research aid in determining the areas in which enhanced school-age child pedestrian safety is required by developing and implementing effective enforcement, educational, and engineering preventive measures.