Counteracting effect of eosin and related dyestuffs on the production of respiration-deficient mutants in yeast by 4-nitroquinoline 1-oxide

Production of respiration-deficient (rho^?) mutants under growing conditions in a strain of Saccharomyces chevalieri by 4-nitroquinoline 1-oxide (4NQO), a potent carcinogen, reached 100%. the mutation frequency was considerably reduced when eosin Y was applied in various combinations with 4NQO. The counteracting effect was slight when eosin Y was applied concurrently with 4NQO, but was very strong adn persistent when eosin Y was impregnated into the yeast cells before their exposure to 4NQO. Eosin B, erythrosin B and uranin also showed more or less counteracting effects against 4 NQO in producing the rho^? mutants. Possible mechanisms for the counteracting effects of these dyestuffs against 4NQO are discussed in relation to antimutagenesis and chemotherapeutic interference.     

Studies of oligosaccharide linkages by simultaneous determination of component aldehydes in dialdehyde fragments as (2,4-dinitrophenyl)hydrazones

The component aldehydes in dialdehyde fragments formed by periodate oxidation of oligosaccharides were converted quantitatively into the corresponding (2,4-dinitrophenyl)hydrazones by the simple procedure of treatment with excess (2,4-dinitrophenyl)hydrazine hydrochloride in 1,2-dimethoxyethane. Then, by chromatographic separation of the hydrazones on a small column of silica gel and subsequent spectrophotometric analysis, it was possible to determine the position of glycosidic substitution in μmolar amounts of various types of glucobioses, oligosaccharides of senega, and some synthetic (1→6)-β-D-gluco-oligosaccharides.     

Observations of Microsporum canis with cryoscanning and scanning electron microscopy

The observations of Microsporum canis with cryoscanning and scanning electron microscopy without fixation and dehydration were reported. In the former an almost native state was observed through showing some fuzzy outlines due to frost; in the latter it was shown that marked shrinkage and distortion had occured. There were many granules on the surface of the macroconidia though their function is uncertain.     

Image Corruption Detection in Diffusion Tensor Imaging for Post-Processing and Real-Time Monitoring

Due to the high sensitivity of diffusion tensor imaging (DTI) to physiological motion, clinical DTI scans often suffer a significant amount of artifacts. Tensor-fitting-based, post-processing outlier rejection is often used to reduce the influence of motion artifacts. Although it is an effective approach, when there are multiple corrupted data, this method may no longer correctly identify and reject the corrupted data. In this paper, we introduce a new criterion called “corrected Inter-Slice Intensity Discontinuity” (cISID) to detect motion-induced artifacts. We compared the performance of algorithms using cISID and other existing methods with regard to artifact detection. The experimental results show that the integration of cISID into fitting-based methods significantly improves the retrospective detection performance at post-processing analysis. The performance of the cISID criterion, if used alone, was inferior to the fitting-based methods, but cISID could effectively identify severely corrupted images with a rapid calculation time. In the second part of this paper, an outlier rejection scheme was implemented on a scanner for real-time monitoring of image quality and reacquisition of the corrupted data. The real-time monitoring, based on cISID and followed by post-processing, fitting-based outlier rejection, could provide a robust environment for routine DTI studies.     

X-Ray Diffractometric Studies on Starches

A linear amylodextrin (average degree of polymerization 12.6) from sweetpotato was crystallized at different temperatures and from different concentrations of solution, and the crystalline type of the recrystallized amylodextrin was examined by X-ray diffraction. It was shown that the crystal type was dependent on the crystallization conditions. The conditions required for the formation of A-, C- and B-type crystals were limited by the following functional relations: 2.5T+C>84, 72<2.5T+C<84, and 2.5T+C<72, respectively, where T is the temperature (°C) at which the amylodextrin was crystallized and C is the concentration (%) of the amylodextrin solution. This relation showed that high temperatures and high concentrations of amylodextrin were favorable for A-type crystal formation and low temperatures and concentrations for B-type crystals, and that the type of crystals formed was more affected by temperature than concentration of the solution.     

Changes in the Phage-Typing Patterns of Staphylococci Following Lysogenization

The phage typing patterns of phage type 52/52A/80/81 staphylococcal strains were changed to type 80/81 and the non-typable group by lysogenization with phages 27 and 146. When a particular strain of Staphylococcus aureus, MS1590 phage type 52/52A/80/81, was lysogenized with phage 146, type 80/81 and the non-typable group strains were produced. According to the comparison of host range of the prophages, it has been concluded that the two strains with different phage typing patterns have different kinds of prophages.