Synthesis and chemistry of silicon and acetylene containing compounds

Cyclic compounds containing silicon-silicon bonds and diacetylene units were synthesized. The photochemical and thermochemical reactions of these compounds were carried out. The cyclic diacetylene, 7,7,8,8,9,9-hexamethyl-7,8,9-trisiladibenzo[e;j]-cycloundeca-1,3-diyne, produced two isomers during these studies. The cyclic diacetylene, 7,7,8,8,9,9,10,10-octamethyl-7,8,9,10-tetrasiladibenzo[e;k]cyclododeca-1,3-diyne, produced four isomers, two of which could not be separated in order to be fully characterized. Single crystal x-ray structures were provided for several of these compounds. The silicon-silicon bonds in these compounds underwent trans-addition across the acetylenes in these cyclic compounds, which differs from the cis-product of the catalytic addition. Possible mechanisms for the reactions also are proposed

A 10-item smell identification scale related to risk for Alzheimer's disease

University of Pennsylvania Smell Identification Test data from control subjects (n = 63), patients with mild cognitive impairment (n = 147), and patients with Alzheimer's disease (n = 100) were analyzed to derive an optimal subset of items related to risk for Alzheimer's disease (ie, healthy through mild cognitive impairment to early and moderate disease stages). The derived 10-item scale performed comparably with the University of Pennsylvania Smell Identification Test in classifying subjects, and it strongly predicted conversion to Alzheimer's disease on follow-up evaluation in patients with mild cognitive impairment. Independent replication is needed to validate these findings

Methylphenidate-Induced Obsessive-Compulsive Symptoms in an Elderly Man

ABSTRACTAn 82-year-old man with treatment-resistant depression and early Alzheimer's disease was started on methylphenidate. Significant obsessive-compulsive behavior ensued but diminished over several weeks when methylphenidate was replaced by fluvoxamine. The patient had no prior psychiatric history, but he had a sister with obsessive-compulsive disorder. It appears that methylphenidate precipitated the patient's pathological behavior.</jats:p