Sensitivity to preservation

The choice between thermal and chemical disinfection depends, to a large extent, on the recommendation of the lens practitioners. Factors involved include the wearer s sensitivity to preservatives, needs, personal hygiene habits, and product cost. Today fewer heat disinfection units are available. 

The image is less sensitive to preserved elastic contrast in the EFTEM images. The ratio cancels out all elastic contrast information that is the same for both pre- and post-edge images. 

Preservatives combine both antimicrobials and antioxidants and are often added to water-containing products such as skin care ointments. In general, contact allergy to preservatives is considered rare. Sensitization to preservatives is often due to the use of products on damaged skin, e.g., eczema or leg ulcers. Patients often present with symptoms of dermatitis of the hands or face. The most frequently used preservatives in cosmetics and topical drugs are parabens, imidazolinidyl urea, quaternium-15, dimethylol-di-methyl (DMDM) hydantoin, phenoxyethanol, met-hylchloroisothiazolinone/methylisothiazolinone, dia-zolinidyl urea, 2-bromo-2-nitropropane-i,3-diol and sorbic acid (Schnuch et al. 1998). Preservatives and antimicrobials are also used in industrial products (called biocides), such as metalwork fluids. 

Creating a well designed, scenic and enhanced parkway that is both safe and beautiful, sensitive to preserving the best of which currently exists, to the maximum extent possible, and that once constructed, the road shall be permanently protected from development pressure so as to maintain the truly unique scenic and agricultural chtuacter of the area for the long term benefit of adjacent landowners, area residents and tourists. 

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