Reproducibility using computer control

An example of the LWC reproducibility using computer control is shown in Figure 2 for a set of un-normalized traces. This represents much improvement over earlier results where manual controls were used. The improvement in LWC variability can be compared with that expected from the theoretically derived uncertainty using a model of... 

Along with the mill, the lathe is also a basic and useful tool, frequently used to build devices precisely. When a large number of replicates have to be built, it is almost mandatory to use computer controlled systems. By this, the desired device is easily reproduced. Computer-controlled CNC mills with a software CAD/CAM that allows the piece design, programming, and executing the movement of the cutting tool are very useful. 

MWNTs favored the detection of insecticide from 1.5 to 80 nM with a detection limit of InM at an inhibition of 10% (Fig. 2.7). Bucur et al. [58] employed two kinds of AChE, wild type Drosophila melanogaster and a mutant E69W, for the pesticide detection using flow injection analysis. Mutant AChE showed lower detection limit (1 X 10-7 M) than the wild type (1 X 10 6 M) for omethoate. An amperometric FIA biosensor was reported by immobilizing OPH on aminopropyl control pore glass beads [27], The amperometric response of the biosensor was linear up to 120 and 140 pM for paraoxon and methyl-parathion, respectively, with a detection limit of 20 nM (for both the pesticides). Neufeld et al. [59] reported a sensitive, rapid, small, and inexpensive amperometric microflow injection electrochemical biosensor for the identification and quantification of dimethyl 2,2 -dichlorovinyl phosphate (DDVP) on the spot. The electrochemical cell was made up of a screen-printed electrode covered with an enzymatic membrane and combined with a flow cell and computer-controlled potentiostat. Potassium hexacyanoferrate (III) was used as mediator to generate very sharp, rapid, and reproducible electric signals. Other reports on pesticide biosensors could be found in review [17],... 

Fig. 11.8. The essential elements of a computer-controlled STM. The feedback electronics is replaced by a single-CPU computer. A Motorola 68020 microprocessor and a 68881 math coprocessor are used to perform the feedback control. A commercial VME crate is applied. The versatility of the software-controlled system facilitates the optimization of the transient response of the STM. (Reproduced from Piner and Reifenberger, 1989, with permission.)...

Quantitative somatosensory testing (QST) uses calibrated tools to assess the function of all the sensory modalities. The smaller caliber nerves are evaluated by measuring pain and temperature (hot and cold) thresholds, and larger caliber nerves are evaluated by measuring the thresholds for perception of vibration, joint position, and touch. This is done by touching the patients skin with stimuli of defined characteristics, such as a computer-controlled probe that can heat or cool to specific temperatures. The effectiveness of QST is limited because it requires subject cooperation and is inherently subjective, as it relies on the reported interpretation of sensory stimulation from the subject. This also influences reproducibility of this sensory test (Fink and Qaklander, 2006). 

Reproducible timing is fundamental to flow analysis and is most effectively achieved by automation, which also allows unattended operation. An on-board computer can be used to control pumps, injection devices and ancillary devices such as switching valves and also for system operation, data acquisition and processing. 

Figure 12. Cell motility assay using the computer-controlled LCD images, (a) An image to measure the ratio of Tetrahymena trap. Trapped cells were marked with black arrows, (b) The ratios of aligned Tetrahymena according to the light contrast. At least five rephcates were conducted. (Reproduced with permission from Ref [25] Copyright 2008, American Institute of Physics.)...

Figure 20.2 A schematic diagram of the set-up using a filtration probe for continuous withdrawal of sample from a fermentor. The filtered sample is led to the FIA system with the heat-sensitive split-flow biosensor. A personal computer was used for controlling the system and for calculation of concentrations. (Reproduced from [25] with permission.)... 

It is seen from figure 22.4 that the peaks are sharp and reproducible. The interpretation of the analytical result may be achieved by measuring either the peak height or the slope of the rising part of the peak, or by integrating the area under the peak. When evaluated manually peak height is the most convenient, and when computer-controlled evaluation is used peak area integration is preferred. 

The procedure and the equipment are simpler than those of FIA. The consumption of buffer is substantially reduced. When working with expensive reagents SIA seems to be preferred over FIA, since much less chemicals are used. There is a need for computer control of the pump in order to achieve a high reproducibility. Most of the work with this method was initially carried out on soluble reagents, but in analogy with FIA it also ought to be useful for immobilized preparations. 

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