Developmental phases

Occasionally, especially in the developmental phase of catalyst research, it is necessary to determine the oxidation state, exact location, and dispersion of various elements in the catalyst. Eor these studies, either transmission electron microscopy (TEM) or scanning electron microscopy (SEM) combined with various high vacuum x-ray, electron, and ion spectroscopies are used routinely. 

During organ formation, cells are continuously lost from the SAM, and these cells have to be replaced through cell divisions in the stem cell zone in order to maintain a functional SAM. The rate of cell divisions and the size of the stem cell population has to be coordinated with the rate of organ formation, which may vary during different developmental phases. How is this coordination achieved, and how can cells in the SAM communicate their position and their fate to each other An... 

The effect of zearalenone on crop development may be connected to its influence on the status and functioning of the photosynthetic apparatus (Koscielniak et al. 2008). The after-effects of zearalenone on the growth of soybean and wheat plants, net photosynthesis and transpiration rates, stomatal conductance, photochemical efficiency of photosystem 2 and on final seeds yield were determined. Modifications in leaf area were more pronounced in soybean than in wheat, and this tendency increases in successive developmental phases. The net photosynthesis was stimulated during the juvenile phase and during that of the final one by about 13.6% (average) in soybean plants. Stimulation of transpiration was also observed after... 

Timing of compoxmds in various developmental phases affects resource requirements. 

Considering that LEH is still in a developmental phase, it is imperative that each batch of LEH is fully characterized for physicochemical and biological properties. Typically, lipid content, particle diameter, oxygen affinity, hemoglobin, methemoglobin, carbonyl-hemoglobin, oncotic pressure, viscosity, endotoxin, and osmolality are determined by conventional methods. Several issues that need specific attention in the case of LEH are as follows ... 

Additional factors may be applied if there are significant shortcomings in the available data that are a cause for concern. If, for example, data relating to the effects of a chemical during the developmental phase are absent, and there are reasons to suspect that the chemical could have such effects (it may, for example, be structurally related to a known developmental toxicant) an additional factor may be applied to the NOAEL. 

Dmg dehvery research in practice reqnires professional planning and careful avoidance of intrinsic pitfalls. Some essential guidelines, derived from our own experience, are hsted in Table 14.1. They shonld not only be taken into acconnt before embarking on a dmg dehvery project, bnt shonld also be integrated dnring the developmental phases of the dmg innovation process. 

Horton VL, Sleet RB,John-GreeneJA, etal Developmental phase-specific and dose-related teratogenic effects of ethylene glycol monomethyl ether in CD-I mice. Toxicol Appl Pharmacol 80 108-118, 1985... 

IN addition to covering traditional areas such as mechanism of action, structure-function relationships, and drug disposition and toxicity, this part of the volume reviews drug-specific data that are specifically pertinent to children and adolescents. Age and developmental phase as critical variables relevant to dosing schemes and side effect liabilities are two recurring themes. Clinical mechanics for using these... 

Terry KK, Elswick BA, Stedman DB, Welsch F (1994) Developmental phase alters dosimetry-teratogenicity relationship for 2-methoxyethanol in CD-1 mice. Teratology, 49 218-227. 

The extent to which intermediate precision should be established depends on the circumstances under which the procedure is intended to be used. The developing analyst should establish the effects of random events on the precision of the analytical procedure and identify which of the above factors contributes significant variability to the final result. The objective of intermediate precision validation is to verify that in the same laboratory the method will provide the same results once the developmental phase is over. 

The evaluation of robustness should be considered during the developmental phase of a method and depends on the type of procedure under study. If measurements are susceptible to variations in analytical conditions, the analytical conditions should be suitably controlled or a precautionary statement should be included in the procedure. Once tire robustness of a method has been established,... 

The suitability of a method for its intended use should be proven in initial experiments. These introductory studies should include the approximate precision, accuracy, detection limit, and working range. If these preliminary validation data appear to be inappropriate, either the method itself or the acceptance limits should be changed. The developer does not know whether the method conditions are acceptable until validation studies are performed. Results of validation studies may indicate that a change in the procedure is necessary, which may then require revalidation. In this way, method development and validation seems to be an iterative process during each developmental phase, key method parameters are determined and then used for all subsequent validation steps. 

The signals necessary to activate or increase the formation of a substance or a regulatory system depend on the point in time and intensity of a specific pathophysiological situation as well as on the respective liver disease and the developmental phase of the ascites. 

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