Abstract: The silicon or silica substrates described have a modified surface of a new type occupied by the alcohol fraction of an orthoester. The alcohol fraction may be saturated or unsaturated. The surface of the substrate is modified by being treated with an orthoester, the water being eliminated from the surface by hydrolysis and then replaced by the resulting alcohol or silylether. Besides many other compounds, new orthoesters having the formula R.sup.1 C?OCH.sub.2 --CH.sub.2 --O--CO--CH.dbd.CH.sub.2 !.sub.3, in which R.sup.1 stands for hydrogen or for a clearable organic residue, R stands for (CH.sub.2).sub.n, in which n stands for an integer between 1 and 18, and new orthoesters having the formula (I), are particularly appropriate. In the formula (I), R.sup.1 stands for hydrogen or an organic residue, R.sup.3 stands for hydrogen or an alkyl group with 1 to 6 carbon atoms; and R.sup.4 stands for hydrogen, an alkyl group or an alkyl group or a phenyl group.

Abstract: The present invention relates to chimeric neurotrophic factors which comprise at least a portion of a naturally occurring cellular factor and a portion of at least one other molecule such that the resulting chimeric molecule has neurotrophic activity. It is based, in part, on the discovery that chimeric molecules comprising portions of both NGF and BDNF are likely to possess neurotrotrophic activity, and in some cases exhibit a spectrum of activity larger than that of either parent molecule. It is further based on the discovery that chimeric molecules comprising neurotrophic factor sequences as well as additional peptide sequences may retain neurotrophic activity, and in some cases may exhibit a more potent activity than the parent factor. The chimeric neurotrophic factor molecules of the invention provide a number of advantages relative to naturally occurring neurotrophic factors.

Abstract: The present invention relates to chimeric neurotrophic factors which comprise at least a portion of a naturally occurring cellular factor and a portion of at least one other molecule such that the resulting chimeric molecule has neurotrophic activity. It is based, in part, on the discovery that chimeric molecules comprising portions of both NGF and BDNF are likely to possess neurotrotrophic activity, and in some cases exhibit a spectrum of activity larger than that of either parent molecule. It is further based on the discovery that chimeric molecules comprising neurotrophic factor sequences as well as additional peptide sequences may retain neurotrophic activity, and in some cases may exhibit a more potent activity than the parent factor. The chimeric neurotrophic factor molecules of the invention provide a number of advantages relative to naturally occurring neurotrophic factors.