PubMed · 11244429
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R P Scholz. 2001. Orthodontic technolocity.. https://doi.org/10.1067/mod.2001.114737
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This technical note describes a new software environment (HIPCOM design environment, HIDE) for the design of custom-made total hip replacements. These devices are frequently designed using general-purpose mechanical computer-aided design (CAD) programs using a set of bone contours extracted from the computer tomography (CT) images as anatomical reference. On the contrary, the HIDE system was developed to let the operator directly design the stem shape onto the CT images in a single-step operation. The operator can directly import CT data in DICOM format or use special functions to reconvert to a digital stack, the CT images printed on a radiological film. Once the stack of CT images is loaded, the operator can design the implant shape by imposing control sections directly on the CT images. The interpolation of these control sections produces the basic 3D shape of the custom-made stem. The shape is then exported to the CAD-computer-aided manufacturing (CAM) program to refine the design and to generate the part program to manufacture the implant with a CNC tooling machine. Using HIDE, the duration of design steps it affected was reduced by more than 50% with respect to the standard method in use at the manufacturer site. HIDE also improved the accuracy and the repeatability of the whole procedure. The learning curve became flat after only ten cases. These good results were achieved because of the integration of the vectorial description of the prosthetic component with the raster description of the CT data that allowed the designer to use all details available in the CT images.
Lipophilicity is a major determinant of pharmacokinetic and pharmacodynamic properties of drug molecules. Correspondingly, there is great interest in medicinal chemistry in developing methods of deriving the quantitative descriptor of lipophilicity, the partition coefficient P, from molecular structure. Roughly, methods for calculating log P can be divided into two major classes: Substructure approaches have in common that molecules are cut into atoms (atom contribution methods) or groups (fragmental methods); summing the single-atom or fragmental contributions (supplemented by applying correction rules in the latter case) results in the final log P. Whole molecule approaches inspect the entire molecule; they use for instance molecular lipophilicity potentials (MLP), topological indices or molecular properties to quantify log P. In this review, representative members of substructure and whole molecule approaches for calculating log P are described; their advantages and shortcomings are discussed. Finally, the predictive power of some calculation methods is compared and a scheme for classifying calculation methods is proposed.
SETTING: This innovative educational programme was developed in the South African context for general practitioners (GPs). AIM: This short report describes the process of designing an Internet-based distance education programme Mental Disorders in Primary Care. LEARNING METHODS: The article discusses relevant educational principles and then describes four stages in the instructional design process: design, development, evaluation and revision. CONCLUSION: The design and development of an Internet-based distance education programme for GPs in South Africa was a potent learning experience for me as an academic family physician with no prior experience in this area. I hope that this short report will assist other people and contribute to an ongoing dialogue on this topic.