Consecutive Transformations of Tetrafluoropropenes: Hydrogermylation and Catalytic C-F Activation Steps at a Lewis Acidic Aluminum Fluoride.

Functionalization reactions of the refrigerants HFO-1234yf (2,3,3,3-tetrafluoropropene) and HFO-1234ze (1,3,3,3-tetrafluoropropene) were developed. The selectivity and reactivity towards CF3 groups of C-F activation reactions can be controlled by employing either a germane or a silane as the hydrogen source. Unique transformations were designed to accomplish consecutive hydrogermylation and C-F activation steps. This allowed for an unprecedented transformation of an olefinic C-F bond into a C-H bond by heterogeneous catalysis. These reactions are catalyzed by nanoscopic aluminum chlorofluoride (ACF) under very mild conditions.

Subjective memory impairment in glioma patients with curative radiotherapy.

BACKGROUND: Radiotherapy in patients with primary brain tumors may affect hippocampal structure and cause dyscognitive side-effects. PATIENTS AND METHODS: Using structural MRI and comprehensive neurocognitive evaluation, we investigated associations between hippocampal structure and memory deficits in 15 patients with WHO grade 3 and grade 4 gliomas receiving standard radio(chemo)therapy. RESULTS: We did not find changes in hippocampal thickness or cognitive abilities three months after completing radiotherapy. However, subjective memory impairment was associated with symptoms of depression, but not with objective memory performance, cortical thickness of the hippocampus or radiation dose. CONCLUSIONS: Irrespective of whether there is a bidirectional relationship between affective changes and subjective cognitive dysfunction in these patients, depressive symptoms remain a target for intervention to improve their quality of life. The results of our pilot study highlight that future assessment of side effects of radiotherapy concerning memory should include assessments of depressive symptoms.

C-F activation reactions at germylium ions: dehydrofluorination of fluoralkanes.

Reactions of the trityl cations with germanes afford the germylium ions [R3Ge][B(C6F5)4] (1a: R = Et, 1b: R = Ph, 1c: R = nBu). These compounds react with germane or fluorogermane to give polynuclear species, which are sources of the mononuclear ions, The latter convert with phosphines to yield the [R3Ge-PR3]+ (4a: R = Et, 4b: R = Ph) cations. Catalytic dehydrofluorination reactions were observed for the C-F bond activation of fluoroalkanes when using germanes as hydrogen source.

Extrinsic and Intrinsic Help-Seeking Motivation in the Assessment of Cognitive Decline.

Diagnostic assessments for dementia include the evaluation of subjective memory impairment, dementia worries, or depressive symptoms. Data on the predictive value of these factors remain unclear, and varying help-seeking behavior may contribute to this finding. We investigate whether differentiating help-seeking motivation from other psychological factors associated with cognitive impairment would enhance the prediction of diagnostic outcomes in a memory clinic. We obtained information on help-seeking motivation from 171 patients who underwent routine diagnostic assessments. Utilizing a discriminant correspondence analysis, our results indicate that extrinsic motivation increases the likelihood of receiving a dementia diagnosis, whereas depression or the duration of deficits carries discriminatory information to further guide the differentiation of prodromal dementia. Recognizing motivational aspects of help-seeking behavior can complement the clinical evaluation of cognitive performance.