28 research outputs found

    Nitrene-carbene-carbene rearrangement. photolysis and thermolysis of tetrazolo[5,1- a ]phthalazine with formation of 1-phthalazinylnitrene, o-cyanophenylcarbene, and phenylcyanocarbene

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    1-Azidophthalazine 9A is generated in trace amount by mild FVT of tetrazolo[5,1-a]phthalazine 9T and is observable by its absorption at 2121 cm-1 in the Ar matrix IR spectrum. Ar matrix photolysis of 9T/9A at 254 nm causes ring opening to generate two conformers of (o-cyanophenyl) diazomethane 11 (2079 and 2075 cm-1), followed by (o-cyanophenyl)carbene 312, cyanocycloheptatetraene 13, and finally cyano(phenyl)carbene 314 as evaluated by IR spectroscopy. The two carbenes 312 and 314 were observed by ESR spectroscopy (D|hc = 0.5078, E|hc = 0.0236 and D|hc = 0.6488, E|hc = 0.0195 cm-1, respectively). The rearrangement of 12 â., 13 â., 14 constitutes a carbene-carbene rearrangement. 1-Phthalazinylnitrene 310 is observed by means of its UV-vis spectrum in Ar matrix following FVT of 9 above 550 C. Rearrangement to cyanophenylcarbenes also takes place on FVT of 9 as evidenced by observation of the products of ring contraction, viz., fulvenallenes and ethynylcyclopentadienes 16-18. Thus the overall rearrangement 10 → 11 → 12 â., 13 â., 14 can be formulated

    Perspectives in Pharmacological Research on Drug Dependence

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    Is older adults’ physical activity during transport compensated during other activities : comparing 4 study cohorts using GPS and accelerometer data

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    Introduction: Promoting active transport offers the potential to increase population physical activity levels. Compensation theories state that above-average physical activity in one activity is compensated in later activities; a mechanism that results in stable levels of total physical activity. Little is known about possible compensation of transport physical activity among older adults. Methods: GPS (Global Positioning System) and accelerometer data collected among older adults (65+) were pooled from four cohorts in Canada, Luxembourg, and France (n=636, collected between 2012 and 2016). Physical activity was measured as total volume of physical activity for trips and non-trip activities. Robust linear regressions on person-centered data were used to test within-person associations between transport and total physical activity. Results: 636 older adults-median age of 76 years, 49% women-provided accelerometer and GPS data for at least 4 days. 18% of the total volume of physical activity was related to transport. A positive association was found between physical activity during a trip and the physical activity during the next hour, among those with lower levels of regular physical activity. Negative associations -indicating partial compensation-were found between transport physical activity during a day, and both total physical activity during the next day and non-transport physical activity during the same day. No differences were found between the four study cohorts. Conclusions: Transport physical activity is compensated partially by older adults during nontransport physical activity. Given the presence of compensation, we strongly recommend evaluations of transport interventions to measure and analyze both non-transport and transport physical activity
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