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Biomedical subjects

A Imre

Publications and source records attributed to A Imre.

5 recordsLinked to original sources

Majority logic gate for magnetic quantum-dot cellular automata.

We describe the operation of, and demonstrate logic functionality in, networks of physically coupled, nanometer-scale magnets designed for digital computation in magnetic quantum-dot cellular automata (MQCA) systems. MQCA offer low power dissipation and high integration density of functional elements and operate at room temperature. The basic MQCA logic gate, that is, the three-input majority logic gate, is demonstrated.

Journal Article↗

Development of a PCR system for the characterisation of Salmonella flagellin genes.

Analysis of flagellin genes was carried out on strains of Salmonella Typhimurium, Salmonella Hadar, Salmonella Abortusequi, Salmonella Enteritidis and Salmonella Gallinarum serovars, using a PCR system designed in this study. The purpose of these studies was to explore the flagellin genes of biphasic and monophasic Salmonellae for future targeted genetic interventions. The PCR primers were designed for two different structural genes of flagellin (fliC, fljB), for the repressor of fliC (fljA), for the operator region of fliC, and for the invertase system responsible for phase variation in Salmonella (hin, hixL, hixR). PCR analysis revealed that all of the examined genes (fliC, fliC-operator, fljB, fljA, hin, hixL, hixR) were present in all S. Typhimurium (n = 10) and S. Hadar (n = 10) strains tested. The results obtained on S. Typhimurium and S. Hadar strains confirmed their biphasic character at DNA level. However, the S. Enteritidis (n = 46) and S. Gallinarum (n = 5) strains lacked the invertase system (hin, hixL, hixR) as well as the fljA and fljB genes, while fliC and its operator were detectable. Consequently, the S. Enteritidis strains could only express fliC gene resulting in phase H1 flagellin. The examined S. Gallinarum strains were also demonstrated to have a cryptic flagellin gene (fliC). On the other hand, PCR results on S. Abortusequi (n = 2) indicated that both flagellin genes (fliC, fljB) and the whole phase variation system were present in both strains tested but only the H2 phase gene (fljB) was expressed. The phenotype of these strains could be clarified by motility test and/or by classical flagellar serology. The findings are also substantiated by the results of serovar-specific PCR for S. Typhimurium and S. Enteritidis. In conclusion, the PCR system developed in this study proved to be suitable for characterisation of Salmonella flagellin genes and confirmed serological results regarding all S. Typhimurium, S. Hadar and S. Enteritidis strains. This system could also identify cryptic flagellar genes of S. Abortusequi and S. Gallinarum.

Animals↗

[Interface between Ni-Cr alloy and ceramic studied by scanning electron microscopy].

In this investigation we observed the interface between Wiron 99 (Bego) dental Ni-Cr alloy and Vision (Wohlwend AG) ceramic opaquer with SEM. In the system there are intermediate phases coming from a solid phase rection which play an essential role in the metal-ceramic bond. The analytical methods showed that in this phases the content of Ni and Cr charge not monotonously from alloy to ceramic which shows strong chemical effects (the selective affinity of Cr and Ni). The concentration of Cr after the alloy surface increases in a 1-1.5 microns layer, where its concentration is higher than at the alloy, while the concentration of Ni decrease in this layer. Than at the ceramic side of the reaction zone the concentration of Ni increases in a 1-1.5 microns wide layer where its concentration is near upon that one in the alloy.

Ceramics↗

[Sealing effectiveness of root canal fillings pretreated with Gluma Dentin Bond].

The root canals of 41 extracted human teeth with single canal were shaped using hand instruments. The canal walls of test roots [22] were pretreated with Gluma resin. All of the canals were filled using the same method. The sealing ability of root canal fillings was evaluated by dye penetration test and the morphology of canal walls was observed by SEM. In the experimental group the dentin bond covered the canal walls completely and the entrances of dentin tubules were obturated. The dentin bond can be observed in the dentinal tubules as well. The mean value of dye penetration was 0.53 mm for the control group and 0.37 mm for the test group. The Gluma pretreatment of root canals increased the sealing ability of AH 26, however, the difference was statistically not significant.

Dental Bonding↗