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1.
The melanoma antigen coded by the MAGE-1 gene was the first tumor antigen described in human cancer. Genetic, biochemical, and "candidate peptide" strategies have been used to identify antigenic peptides presented to T-cells by class I major histocompatibility complex antigens. Antigens have now been characterized in a wide variety of tumor types. Five categories have been described based on expression profile. These antigens are detailed in this review. Among the tumor antigens produced as a result of intratumoral mutations, some are of special interest because of their potentially oncogenic effects. These new data can be expected to lead to the development of novel anticancer treatments based on specific immunotherapy. Pilot clinical studies are ongoing.  相似文献   
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This study was aimed at assessing the prevalence of pathogenic Escherichia coli strains, relative to the total count of E. coli, faecal coliforms and other heterotrophic mesophilic aerobic bacteria (HMAB) isolated in groundwater in the equatorial region of Cameroon (Central Africa). Bacteria were isolated using standard methods. Pathogenic E. coli strains were then identified using haemagglutination and antisera tests. The maximum abundance of HMAB, faecal coliforms and E. coli strains were 4.9 × 106, 5.6 × 103 and 1 × 103 colony‐forming units (CFU)/100 mL, respectively. The count of pathogenic E. coli strains reached 3 CFU/100 mL. The counts of commensal and pathogenic E. coli strains underwent temporal and spatial fluctuations. In 21% of sampling sites, the abundance of faecal coliforms was significantly correlated to that of E. coli (P < 0.05). However, the isolated bacterial count was not significantly correlated to that of the pathogenic E. coli strains (P > 0.05). The bacteria abundance dynamics may be impacted by many interacting factors.  相似文献   
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The corrosion of fuel cladding and structural materials by lead and lead-bismuth eutectic in the liquid state at elevated temperatures is an issue that must be considered when designing advanced nuclear systems and high-power spallation neutron targets. In this work, lead corrosion studies of molybdenum were performed to investigate the interaction layer as a function of temperature by X-ray absorption spectroscopy. In situ X-ray absorption measurements on a Mo substrate with a 3-6 μm layer of Pb deposited by thermal evaporation were performed at temperatures up to 900 °C and at a 15° angle to the incident X-rays. The changes in the local atomic structure of the corrosion layer are visible in the difference extended X-ray absorption fine structure and the linear combination fitting of the X-ray absorption near-edge structure to as-deposited molybdenum sample and molybdenum oxide (MoO2 and MoO3) standards. The data are consistent with the appearance of MoO3 in an intermediate temperature range (650-800 °C) and the more stable MoO2 phase dominating at high and low temperatures.  相似文献   
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White storks (Ciconia ciconia) fed in contaminated waters resulting from the Aznacollar acid mining-sludge spillage into the R. Guadiamar, which feeds the eastern flank of the Guadalquivir marshes (Do?ana), S.W. Spain. The sludge was rich in a range of toxic elements, and in organic pollutants such as the aromatic amines. Storks did not exhibit elevated metals in their blood immediately following the accident, but chick blood collected the year following the accident showed genotoxic damage compared to the controls. In this study lead isotope analysis was used to assess if the storks had ingested sludge-derived contaminants. The sludge lead isotope ratio was distinct from that of the Do?ana sediments. The stork blood lead isotope ratios exactly matched that of the sludge. It was concluded that the storks had ingested sludge-derived contaminants. A detailed study of the lead contamination along the R. Guadiamar and the R. Guadalquivir (of which the Guadiamar is a tributary) was also conducted to place the white stork colony lead exposure in the context of the spatial contamination of the storks' habitat.  相似文献   
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Filtering Edges by Pixel Integration   总被引:1,自引:0,他引:1  
An algorithm is presented which evaluates the area of the triangles formed by the intersection of a straight-line boundary with pixel elements, yet involves only tests and additions.  相似文献   
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Conclusions One cardinal principle guided our evaluation of the data provided for us by the computer: never to be deluded into believing that the computer was in any way capable of analyzing a piece of music. Rather, we used the information made available by the computer as a means of substantiating or explaining the insights into a given composition that we gained by means of a direct confrontation with the music. In this way, the data supplied by the computer proved to be very useful in explaining why a particular portion of a chanson generates a sense of tension, while another section of the same piece creates a feeling of rest. Similarly, the electronically derived information was particularly helpful in setting up stylistic profiles of the various composers whose chansons were included in our sampling. In fact, the computer output was instrumental in helping to settle more than one problem of conflicting attributions, largely on the basis of these stylistic profiles. Like any other computerized process, our program elicited from the computer no analytical operation that could not have been done without the assistance of the computer. Very little precise measurement has been done in the analysis of the music of the Renaissance, however, and for good reason: the compilation of statistical data of the type we have described takes so much time that it can be considered feasible only with mechanical assistance. The ability we gained to apply to the chanson repertory a somewhat more precise system of analytical measurement was the most encouraging aspect of the pilot project. candidate for the Ph.D. in Physics  相似文献   
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Phosphatidylinositol 3(PI3)-kinase is implicated in various biological responses, including protection from apoptosis, although its role in antigen-induced T cell death and the molecular effectors it triggers remains ill-defined. Here, we investigated the role of PI3-kinase activity in the prevention of T cell receptor/CD3-induced cell death by CD28. PI3-kinase inhibitors blocked the up-regulation of Bcl-X(L) by CD28, without impairing the prevention of T cell receptor/CD3-triggered apoptosis by CD28, hence showing the existence of a cell-survival pathway independent of PI3-kinase activity and up-regulation of Bcl-X(L). Instead, we show that up-regulation of FasL which is instrumental in CD3-induced apoptosis was prevented upon CD28 co-stimulation. These results indicate that PI3-kinase couples CD28 to Bcl-X(L) up-regulation and provide a molecular basis for the role of CD28 in cell survival through a PI3-kinase-independent mechanism including FasL down-regulation.  相似文献   
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The present article presents a method for assessing the radial stiffness of nitinol stents. An idealized stent model was created, and its radial stiffness was calculated by means of finite element modeling. The calculations were validated against experimental measurements. The variation of radial stiffness with geometrical dimensions was calculated, and the effect of increasing radial stiffness on endovascular deployment was analyzed. Peak tensile and compressive stresses as well as stent penetration were calculated in the case of an idealized pulmonary artery model having realistic dimensions as well as stiffness. The results of stress calculations were compared with a second set of simulations, where an idealized behavior of the stent (uniform expansion to a theoretical contact diameter) was modeled. The results show how in reality nitinol stents behave in a non-ideal way, having a non-uniform expansion and exerting non-uniform pressure on the contact areas with the artery. Such non-ideality decreases though with the increase in radial stiffness. The radial force alone may be insufficient in describing the stent-artery interaction, and numerical modeling proves to be necessary for capturing such complexity.  相似文献   
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