Liquid development disadvantages

We have developed a new method of interpretation of the photographs which does not suffer from this disadvantage. This radial distribution method, which is closely related to the method of interpretation of x-ray diffraction data developed by Zemike and Prins3 for the study of the structure of liquids and applied by Warren and Gingrich4 to crystals, consists in the calculation (from... 

The disadvantages of this type of toilet system are the high usage of sanitiser and high volume of liquids/solids for subsequent disposal. This led to the development of the vacuum toilet system. 

The NRTL equation developed by Renon and Prausnitz overcomes the disadvantage of the Wilson equation in that it is applicable to immiscible systems. If it can be used to predict phase compositions for vapour-liquid and liquid-liquid systems. 

Gel-Forming Solutions. One disadvantage of solutions is their relatively short residence time in the eye. This has been overcome to some degree by the development of solutions that are liquid in the container and thus can be instilled as eyedrops but gel on contact with the tear fluid and provide increased contact time with the possibility of improved drug absorption and increased duration of therapeutic effect. 

On the basis of the preceding discussion, it should be obvious that ultratrace elemental analysis can be performed without any major problems by atomic spectroscopy. A major disadvantage with elemental analysis is that it does not provide information on element speciation. Speciation has major significance since it can define whether the element can become bioavailable. For example, complexed iron will be metabolized more readily than unbound iron and the measure of total iron in the sample will not discriminate between the available and nonavailable forms. There are many other similar examples and analytical procedures that must be developed which will enable elemental speciation to be performed. Liquid chromatographic procedures (either ion-exchange, ion-pair, liquid-solid, or liquid-liquid chromatography) are the best methods to speciate samples since they can separate solutes on the basis of a number of parameters. Chromatographic separation can be used as part of the sample preparation step and the column effluent can be monitored with atomic spectroscopy. This mode of operation combines the excellent separation characteristics with the element selectivity of atomic spectroscopy. AAS with a flame as the atom reservoir or AES with an inductively coupled plasma have been used successfully to speciate various ultratrace elements. 

Traditionally, HAT activity is measured with a discontinuous radioactive filterbinding assay, which uses pH]acetyl-CoA as a histone acetyltransferase substrate [46]. The transfer of [ H]acetyl-groups to the histone substrate by histone acetyltransferases is detected by liquid scintillation counting of pHjacetylated histones, which are retained on a phosphocellulose disk. Due to its discontinuous character, this assay is technically problematic and not ideal for kinetic analysis. Hence, other assays that work with radiolabeled acetyl-CoA have been described that are suitable for a higher throughput. These work with streptavidin-covered beads [47] or a variant of the SPA with microtiter plates that contain a scintillant (FlashPlates) [48]. But as all these protocols are based on radioactively labeled substrates, they apparently show the same disadvantages that were described for the radioactive HDAC assay protocols. Therefore, nonradioactive assays have been developed to study histone acetyltransferase activity. 

---