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Abstract Synthesis of the cyclopentene carbocyclic analogue of the naturally occurring nucleoside clitocine ( 1 ) is reported. Starting with racemic cyclopentenylamine ( 10 ), the heterocyclic moieties of the clitocine analogue 4 and related 1,6‐dihydro‐6‐oxo, 5 , and 2‐amino‐1,6‐dihydro‐6‐oxo, 6 , analogues were constructed. These compounds were respectively converted to 8‐aza‐neplanocin A (7) , 8‐aza‐neplanocin D ( 8 , the inosine analogue), and the corresponding 8‐aza‐guanosine analogue 9 after reduction of the nitro group followed by nitrous acid cyclization. Extensive antiviral evaluation revealed that only 8‐aza‐neplanocin A ( 7 ) had enough antiviral activity to warrant further studies. This compound showed weak antiviral activity against HSV‐1, HSV‐20 and the thymidine kinase deficient (TK‐) HSV‐1. However, it displayed good antiviral activity against human cytomegalovirus (HCMV) at a concentration of 0.40–2.50 μg/ml, well below the cytotoxicity threshold. This activity profile is consistent with a mechanism of action involving the inhibition of the enzyme adenosylhomo‐cysteine hydrolase.
Topical BVDU [(E)-5-(2-bromovinyl)-2′-deoxyuridine] application (i.e. 0.1% BVDU eye drops) has proven to be highly efficacious in the treatment of both epithelial and stromal herpes simplex keratitis, both in rabbits and humans.
In product design, a CAD model often needs to be constructed from a physical part. This process is called reverse engineering and is performed through dimensional digitising and CAD modelling. The dimensional digitising results in a cloud of points, which are input for the CAD modelling of surfaces corresponding to the object's features. Consistent with these features, some of the modelled surfaces need to join with positional, tangential or curvature continuity. This paper reports on the incorporation of these geometric boundary conditions in the CAD modelling of free-form surfaces from a cloud of points with non-uniform rational B-splines (NURBS). The described methods are illustrated with some practical, industrial examples and some alternative solutions are briefly described.
No abstract is provided for this article.
The paper describes the experiences with a Belgian Primary Care data Network from 1999 till 2002. Three cycles of data collection have been performed. The network involves about 300 general practitioners (GPs) and up to 8 different software packages. This network is semi-anonymous, semi-automatic and mixed (paper and electronic with various software's). For the coming next years, efforts should be focused on solving some frequently occurring problems with the data collection through the EPR, such as a considerable number of data lacking and the fact that GPs do not always use the problem oriented structure of the EPR (Electronic Patient Record). Afterwards, more promising usage could be considered and developed such as repeated data collection using a same GPs' sample, long-term recording studies, usage of larger GPs' samples, etc.