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  • Author or Editor: M. Novák x
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Abstract  

A simple, sensitive and reliable method was developed for the determintion of hydrazine in technological waters of NPPs. A pulverized mixture of oxalic acid and p-dimethylaminobenzal dehyde is added to a sample. As low as 1.5 g.dm–3 hydrazine can be determined. The method is dependent of the sample temperature. The agent is stable, readily soluble in water, and not hygroscopic.

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Mutant soybean germplasm was developed from a Carpathian-Ukrainian local variety, using 100–300 Gy chronic gamma irradiation to obtain lines with improved oil and/or protein content. The mutant germplasm was developed by the pedigree method. Selection for high oil and protein content started in the M3 generation. Plants with 24.1 and 23.6% oil content in the seeds were detected in the M4 generation. There were negative, moderate (r = –0.4) and significant (P<0.1 and P<0.01) correlations between the oil content and the 1000-seed weight in both the M3 and M4 generations. The fatty acid composition in the seeds of plants with high oil content was favourable. It is suggested that selection for oil content in the seeds should be started in the M4 generation. Due to the limited genetic variation for protein content no mutant genotypes with higher protein content than that of the control could be identified.

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Abstract  

A short overview of HPLC column packings is presented. The properties of chromatographic carriers and the possibilities to combine the solid matrices with organic polymeric stationary phases are elucidated in detail. The latest achievements and anticipated future developments in the area are outlined.

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Abstract  

Differential scanning calorimetry (DSC) is applicable to studying the thermal properties of bacteria when treated with heat, cold, or antibiotics. Foodborne pathogens are inactivated by heat, and denaturation transitions observed by DSC indicate potential sites of cellular injury. Ribosomes, which are the sites for messenger RNA translation, are one critical component of thermal damage as evidenced by characteristic denaturation transitions in the 66-74C range. These transitions disappear when cells of Clostridium perfringens are subjected to heat, suggesting structural or conformational changes to ribosomal proteins, and when cells of Listeria monocytogenes are cold-shocked by refrigeration, indicating ribosomal dissociation. DSC can be used to show that refrigeration followed by heat treatment improves the killing of dangerous microorganisms.

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Solid inclusion complexes of TolperisoneHCl with five various cyclodextrins were prepared by kneading and spray drying. The complex formation between the drug and the cyclodextrins were proven using thermoanalytical methods, X-ray diffraction, IR spectroscopy. The results of the solid state investigations were supported by the liquid phase investigations, such solubility and parition constant measurements and stability constant determination. Among all cyclodextrins used the β- and γ-CD-s were found to be the best complexing agents.

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A new unstable organ-specific Adh1 mutant was isolated from autotetraploid S 25 Wf9 maize line after germinating kernels under water for two days. Adh1-Fm4x-1 expresses normal and/or reduced levels of ADH1 in anaerobic scutellum. No activity or approximately 33–75% of wild type level of ADH1 in pollen grains was observed. The organ-specific phenotype of the Adh1-Fm4x-1 could be maintained by selfing for ten subsequent generations. After crossing with the wild-type allele the Adh1 mutation transmitted to the next generation both by female and male gametophytes. The appearance of one- and two-banded patterns in anaerobic scutellum and pollen grains of heterozygous F 1 plants showed the lack of F·F homodimers.DNA sequence analyses of the wild type allele, the Adh1-Fm4x-1 mutant allele and four F 1 revertants revealed that the Adh1-Fm4x-1 mutation contains a Dissociation (Ds1) transposable element in the 5′ untranslated leader of the maize Adh1 gene, which regulates organ-specific expression at a quantitative level.

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An assemblage of moth species at a suburb of Prague (50°5′11″N,14°18′06″E) was monitored by a highly efficient mercury light trap for 23 years (1967–1976, 1980–1992). Species caught were divided into guilds according to habitat specialisation, and analysed using species richness S , Shannon’s diversity H and evenness J as the response variables, and the individual years of monitoring and effects of mean annual temperature and precipitation as the explanatory variables. Overall, 424 species were recorded: 25 early successional arable land species (43% of all caught individuals), 116 forest species feeding on trees and shrubs, 33 forest species feeding on woodland herbs and lichens, 92 forest-steppe species, 116 grassland species, 28 wetland species, and 14 non-specialized generalists. The diversity of habitat-specialised species responded mainly to land use changes, whereas the diversity of generalists reflected long-term meteorological trends. Species richness of specialists whose habitats in the vicinity of the trap have declined in extent decreased, the numbers of those whose habitats remained intact did not exhibit any particular trend, whereas the numbers of generalists increased, and their diversity positively responded to warming. It is concluded that the habitat specialists and generalists react to environmental changes differently. Non-specialised species appear more sensitive indicators of climate changes than habitat specialists because for the latter the indication of climate changes can be overlaid by changes in habitat use.

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Seed protein pattern of control and M 10 mutant soybean ( Glycine max [L.] Merr.) lines in defatted and non-defatted raw flour was studied after 60% 2-propanol extraction, SDS-PAGE separation, colloidal staining and densitometric evaluation to detect a new variant of the protein KTI and/or BBI, furthermore to find new protein(s) of low molecular weight. Electrophoretic separation of defatted and non-defatted control soybean samples showed the same protein patterns. On the densitograms of mutant lines quantitative and qualitative differences could be observed. Defatted raw soy samples reflected more differences in the number of peaks than non-defatted ones. Beside soy trypsin inhibitors, several more soy proteins of low molecular weight are dissolved. KA mutant line 9 has a unique 2-propanol soluble protein pattern, and a new protein band of Rf=0.37 compared to the control line. Sixty percent 2-propanol soluble soybean seed proteins are suitable for cultivar identification and characterization, furthermore to distinguish soybean lines of the same origin.

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