Stepwise development

Ascending, one-dimensional stepwise development in a twin trough chamber without chamber saturation. 

Method Ascending, one-dimensional, stepwise development (5 min inter-... 

Fig. 3 Stepwise development of antiviral resistance. Because of the rapid mutation rate of viruses, the virus population before treatment (a) contains variants, which display by chance a low level of resistance to the drug (indicated by the darker hue). Treatment with suboptimal levels of an antiviral drug (b) creates a bottleneck, which selects for these variants (c). These can further replicate in the presence of the drug and thereby acquire additional mutations, leading to resistant variants with enhanced replicative fitness (d)...

Ascending, one-dimensional, stepwise development (5 min intermediate drying in a stream of cold air) in a trough chamber at 20 °C without chamber saturation. 

Comparison of chemiluminescence isothermal runs with oxygen uptake and DSC measurements has been at the centre of interest since practical industrial applications of the chemiluminescence method were attempted. It is a fact that the best comparison may be achieved when studying polymers that give a distinct induction time of oxidation typical for autoaccelerating curves of a stepwise developing oxidation. This is the particular case of polyolefins, polydienes and polyamides. The theoretical justification for the search of a mutual relationship between the oxidation runs found by the various methods follows directly from the kinetic analysis of the Bolland-Gee scheme of polymer oxidation. 

Farber, E. (1984). Cellular biochemistry of the stepwise development of cancer with chemicals G.H.A. Clowes Memorial Lecture, Cancer Res. 44, 5463. 

On the basis of this finding, a two-step (stepwise) development technique12 was applied to separations of possible three binary mixtures of polybutadienes with different chain microstructure, namely, those of cis-1,4 + tram-1,4, tram-1,4+1,2-1,2-vinyl, and 1,2-vinyl + cis-1,4. The principle consisted of a utilization of the different development characteristics exhibited by carbon tetrachloride and amyl chloride. An example of this procedure applied by these authors83 will be described below. A mixture cis-1,4 + tram-1,4 was developed primarily with amyl chloride until the solvent front reached a distance, e.g., 10 cm from the starting point by this development only the cis-1,4 polymer should have migrated up to the solvent front (cf. Table 4). In order to identify the immobile component, the chromatogram was dried in vacuum at room temperature and treated with carbon tetrachloride until the solvent front reached an intermediate distance, e.g., 5 cm. It is obvious that this procedure can be alternatively used for identification of any unknown binary mix-... 

Of the two types of resistance identified, aerobic resistance is of clinical importance as most clinical isolates from treatment-refractory patients show resistance of this type. However, findings regarding the stepwise development of resistance, and continuity of resistance development from the aerobic to the anaerobic type, point to the possibility that I vaginalis strains at the early stage of anaerobic resistance could also appear in the field. In fact, some isolates reported from Upcroft s laboratory (Dunne al. 2004) and occasional isolates from surveys (e.g., Lossick et al. 1987) displaying high aerobic MLC... 

Nelson, R.L. Garry, V.F. (1983) Colony transformation in C3H lOTl/2 cells stepwise development of neoplasic change in vitro. In lltro, 19, 551-558... 

Standardization is obviously of paramount importance to data mining. Programming resources are scare, and data locked in unsupported formats can be lost forever. However, whereas the basic idea that standards are useful is generally shared, the real-world situation is far from ideal. In a perfect world, standards would be developed first and agreed upon by all interested parties. With these standards in hand, interoperable products would be developed, but experience shows most standards created this way utterly fail. Standardization is a complex process, and experience is only gained through stepwise development and usage. 

Figure 9-5. Intermediate values for stepwise development of interpolation formula.

Mitnick MA, DeMarco B, Gibbons JM. Amniotic fluid phosphatidylglycerol and phosphatidylinositol separated by stepwise-development thin-layer chromatography. Chn Chem 1980 26 277-81. 

Farber, E., Hepatocyte proliferation in stepwise development of experimental liver cell cancer, Dig. Dis. Sci., 36, 973, 1991. 

For the separation of substances having small Rf values, it is advisable to run the TLC plate more than once, drying the layer before it is developed again. If the solvents used for subsequent runs are the same as in the first run it is called multiple or repeated development, but when the solvents are different in the first and later runs, the technique is called stepwise development. These techniques are specially useful for mixtures which contain polar as well as non-polar substances. Polar solvent systems are usually employed for the first run and a non-polar solvent system for the later runs. 

Franz, R., M. Ruhnke, D.C. Lamb, S.L. Kelly, and J. Morschhauser (1998). Multiple molecular mechanisms contribute to a stepwise development of fluconazole resistance in clinical Candida albicans strains. Antimicrob. Agents Chemother. 42, 3065-3072. 

In TLC, although continuous solvent programming is feasible, it is seldom used because it is experimentally inconvenient. Stepwise development or two-dimensional TLC is used instead. More recently, programmed multiple development with the same solvent system has been introduced. 

Previous sections have attanpted to provide a rational, basic understanding of the processes that occur in the mass spectrometer following electron bombardment. A stepwise development of the chemistry of fragmentation and a short introduction to the principles and instrumentation were deemed prerequisite to the fuU use of mass spectrometric data. We can now begin to examine mass spectra with the intention of elucidating the structures of unknown compounds. In this chapter, a general format for examining mass spectra is developed, or, more correctly, several formats... 

Although the concepts of justification of practices, optimization of protection, dose commitment, and collective dose were all already treated and considered in the ICRP Publication 9 (1965), they were explicitly expressed not until in the ICRP Publication 26 (1977). The implementation of the new approach after 50 years of stepwise development meant adaptation of a modem protection concept which in a refined and addended form is continuously iqiplicable. 

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