Some advantages

One major advantage offered by cultured cells which cell biologists make full use of but which is often ignored by biochemists is that the living cells may be watched under the microscope. It is essential that healthy cells are used in an experiment and that they remain alive throughout the experiment. That this is the case may be monitored regularly and moreover quantitative estimates of the proportion of viable cells are readily obtained. It is often impossible to know the state of an animal s kidney until the end of the experiment and then usually only in a qualitative manner. 

Cells in culture offer a homogeneous population of cells of virtually identical genetic make-up, growing in a constant environment. Moreover, the environment may be changed, within limits, at 

Moreover, significant results may be obtained with very few cells. An experiment which may require 100 rats or 1000 humans in order to clarify some point may be statistically equally valid if 100 coverslip cultures or one microwell plate are used. If each cell is regarded as an independent experiment then one coverslip culture may yield more reliable results than a hospital full of people. This is obviously a major advantage as far as man is concerned but also overcomes the ethical problems which often arise when large numbers of animals are used for experimental purposes. However, in the final analysis, many experiments must be performed on whole animals, but this is no justification for not using cultured cells for the preliminary work. 

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The density of heavy fuels is greater than 0.920 kg/1 at 15°C. The marine diesel consumers focus close attention on the fuel density because of having to centrifuge water out of the fuel. Beyond 0.991 kg/1, the density difference between the two phases —aqueous and hydrocarbon— becomes too small for correct operation of conventional centrifuges technical improvements are possible but costly. In extreme cases of fuels being too heavy, it is possible to rely on water-fuel emulsions, which can have some advantages of better atomization in the injection nozzle and a reduction of pollutant emissions such as smoke and nitrogen oxides. 

Here fg is the centre frequeney and Af the 6 dB bandwidth. Apart from being simple, this spectmm has Some advantages. With a given bandwidth only a frequency band that is twice the bandwidth need to be computed and this is very important as it leads to a minimal number of... 

On a larger scale, deuterium oxide has been used as a moderator in nuclear reactors, having some advantages over graphite. 

The alicyclic secondary alcohol, cycZohexanol, may be dehydrated by concentrated sulphuric acid or by 85 per cent, phosphoric acid to cyciohexene. It has a higher boiling point (82-83°) than amylene and therefore possesses some advantage over the latter in.the study of the reactions of unsaturated hydrocarbons. 

The MTG process accomplishes the same end as the Eischer-Tropsch process, but each method has some advantages. The Eischer-Tropsch... 

Ultrasonic Microhardness. A new microhardness test using ultrasonic vibrations has been developed and offers some advantages over conventional microhardness tests that rely on physical measurement of the remaining indentation size (6). The ultrasonic method uses the DPH diamond indenter under a constant load of 7.8 N (800 gf) or less. The hardness number is derived from a comparison of the natural frequency of the diamond indenter when free or loaded. Knowledge of the modulus of elasticity of the material under test and a smooth surface finish is required. The technique is fast and direct-reading, making it useful for production testing of similarly shaped parts. 

The compound was first made commercially in England during World War II as a substitute for sodium peroxoborate, which could no longer be made because of a shortage of borax. It offers some advantages over the peroxoborate and has grown to be an important industrial chemical. 

Chemical Processing Intermediates and Other Applications. Monoethanolamine can be used as a raw material to produce ethylenedianiine. This technology has some advantages over the ethylene dichloride process in that salts are not a by-product. Additional reactions are requked to produce the higher ethyleneamines that are normally produced in the ethylene dichloride process. 

The need for low levels of 3-isomer in 2-thiophenecarboxyhc acid [527-72-0] which is produced by oxidation of 2-acetylthiophene [88-15-3] and used in dmg appHcations, has been the driving force to find improved acylation catalysts. The most widely used oxidant is sodium hypochlorite, which produces a quantity of chloroform as by-product, a consequence that detracts from its simplicity. Separation of the phases and acidification of the aqueous phase precipitate the product which is filtered off. Alternative oxidants have included sodium nitrite in acid solution, which has some advantages, but, like the hypochlorite method, also involves very dilute solutions and low throughput volumes. 

The cervical cap birth control device has been available in Europe for many years and in the U.S. since late 1988. It is a small, mbber, dome-shaped device that fits snugly over the cervix. The cervical cap has some advantages over the diaphragm, but has not Hved up to widespread expectations that it would become an overwhelmingly popular method of contraception (100). 

E. Basolo and R. G. Pearson, Mechanisms of Inorganic Reactions, 2nd ed., John Wiley Sons, Inc., New York, 1967. An excellent volume that stresses the reactions of complexes ia solution a background and a detailed theory section is iacluded that is largely crystal field theory, but some advantages and disadvantages of molecular orbital theory are iacluded. 

The choice of initiator system depends on the polymerization temperature, which is an important factor in determining final product properties. Cold polymers are generally easier to process than hot polymers and in conventional cured mbber parts have superior properties. The hot polymers are more highly branched and have some advantages in solution appHcations such as adhesives, where the branching results in lower solution viscosity and better cohesion in the final adhesive bond. 

Some advantages of paper in electrophoresis are that paper is readily available, easy to handle, and new methodologies can be developed rapidly. The disadvantages of paper electrophoresis are that the porosity of paper caimot be controlled, the technique is not very sensitive, and it is not easily reproducible. 

A recent addition to the model-based tuning correlations is Internal Model Control (Rivera, Morari, and Skogestad, Internal Model Control 4 PID Controller Design, lEC Proc. Des. Dev., 25, 252, 1986), which offers some advantages over the other methods described here. However, the correlations are similar to the ones discussed above. Other plant testing and controller design approaches such as frequency response can be used for more complicated models. 

Some advantages of the Fmoc protective group are that it has excellent acid stability thus BOC and benzyl-based groups can be removed in its presence. It is readily cleaved, nonhydrolytically, by simple amines, and the protected amine is liberated as its free base. The Fmoc group is generally considered to be stable to hydrogenation conditions, but it has been shown that under some circumstances it can be cleaved with H2/Pd-C, AcOH, MeOH, (t /2 = 3-33 h). ... 

Some advantages of vticutim circuit breakers are summarized below ... 

Some advantages and disadvantages of SSI analysis have also been summarized (Sadlon, 1993) ... 

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