Early-time measurements of laser-plasma conditions in omega-upgrade ICF targets. Semi-annual report, October 1, 1997--March 31, 1998

AbstractThe dual laser-produced plasma technique for the study of ionic absorption spectra has been developed by the use of two Q-switched ruby lasers to enable independent generation of the absorbing and back-lighting plasmas. Optical pulse handling is used in the coupling cicuits to enable reproducible pulse delays from 250 nsec. to 10 msec, to be achieved. At delay times > 700 nsec. spectra of essentially pure neutral species are observed. The technique is valuable, not only for obtaining the neutral spectra of highly refractory and/or corrosive materials but also for studying behaviour of ionic species as a function of time. Typical spectra are shown in Fig. 1.

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Cytochemical Studies of Cell Wall Biosynthesis in Staphylococcus Aureus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094905 ◽

1972 ◽

Vol 30 ◽

pp. 328-329

Author(s):

Masaatsu Koike ◽

Koichi Nakashima ◽

Kyoko Iida

Keyword(s):

Staphylococcus Aureus ◽

Periodate Oxidation ◽

Early Time ◽

The Other ◽

Penicillin G ◽

Cell Wall Biosynthesis ◽

Septal Wall ◽

Peptidoglycan Biosynthesis ◽

Gram Positive Bacteria ◽

Cross Linkage

Penicillin exerts the activity to inhibit the peptide cross linkage between each polysaccharide backbone at the final stage of wall-peptidoglycan biosynthesis of bacteria. Morphologically, alterations of the septal wall and mesosome in gram-positive bacteria, which were occurred in early time after treatment with penicillin, have been observed. In this experiment, these alterations were cytochemically investigated by means of silver-methenamine staining after periodate oxidation, which is applied for detection of localization of wall mucopolysaccharide.Staphylococcus aureus strain 209P treated with 100 u/ml of penicillin G was divided into two aliquotes. One was fixed by Kellenberger-Ryter's OSO4 fixative at 30, 60 and 120 min after addition of the antibiotic, dehydrated through alcohol series, and embedded in Epon 812 (Specimen A). The other was fixed by 21 glutaraldehyde, dehydrated through glycolmethacrylate series and embedded in glycolmethacrylate mixture, according to Bernhard's method (Specimen B).

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