1,117 research outputs found
Efficient and Practical Transfer Hydrogenation of Ketones Catalyzed by a Simple Bidentate MnâNHC Complex
Catalytic reductions of carbonylâcontaining compounds are highly important for the safe, sustainable, and economical production of alcohols. Herein, we report on the efficient transfer hydrogenation of ketones catalyzed by a highly potent Mn(I)âNHC complex. MnâNHC 1 is practical at metal concentrations as low as 75â
ppm, thus approaching loadings more conventionally reserved for noble metal based systems. With these low Mn concentrations, catalyst deactivation is found to be highly temperature dependent and becomes especially prominent at increased reaction temperature. Ultimately, understanding of deactivation pathways could help close the activity/stabilityâgap with Ru and Ir catalysts towards the practical implementation of sustainable earthâabundant Mnâcomplexes
Desynchronization during anticipatory attention for an upcoming stimulus: A comparative EEG/MEG study
Objectives: Our neurophysiological model of anticipatory behaviour (e.g. Acta Psychol 101 (1999) 213; Bastiaansen et al., 1999a) predicts an activation of (primary) sensory cortex during anticipatory attention for an upcoming stimulus. In this paper we attempt to demonstrate this by means of event-related desynchronization (ERD). Methods: Five subjects performed a time estimation task, and were informed about the quality of their time estimation by either visual or auditory stimuli providing Knowledge of Results (KR). EEG and MEG were recorded in separate sessions, and ERD was computed in the 8± 10 and 10±12 Hz frequency bands for both datasets. Results: Both in the EEG and the MEG we found an occipitally maximal ERD preceding the visual KR for all subjects. Preceding the auditory KR, no ERD was present in the EEG, whereas in the MEG we found an ERD over the temporal cortex in two of the 5 subjects. These subjects were also found to have higher levels of absolute power over temporal recording sites in the MEG than the other subjects, which we consider to be an indication of the presence of a `tau' rhythm (e.g. Neurosci Lett 222 (1997) 111). Conclusions: It is concluded that the results are in line with the predictions of our neurophysiological model
Vegetation succession and herbivory in a salt marsh:Changes induced by sea level rise and silt deposition along an elevational gradient
Vegetation succession and herbivory in a salt marsh:Changes induced by sea level rise and silt deposition along an elevational gradient
The use of the asymptotic expansion to speed up the computation of a series of spherical harmonics
Impact of mammographic screening and advanced cancer definition on the percentage of advanced-stage cancers in a steady-state breast screening programme in the Netherlands
Background: To estimate the percentages of advanced-stage breast cancers (BCs) detected during the course of a steady-state screening programme when using different definitions of advanced BC. Methods: Data of women aged 49â74 years, diagnosed with BC in 2006â2015, were selected from the Netherlands Cancer Registry and linked to the screening registry. BCs were classified as screen-detected, interval or non-screened. Three definitions of advanced BC were used for comparison: TNM stage (IIIâIV), NM stage (N+ and/or M+) and T size (invasive tumour â„15 mm). Analyses were performed assuming a 10% overdiagnosis rate. In sensitivity analyses, this assumption varied from 0 to 30%. Results: We included 46,734 screen-detected, 17,362 interval and 24,189 non-screened BCs. By TNM stage, 4.9% of screen-detected BCs were advanced, compared with 19.4% and 22.8% of interval and non-screened BCs, respectively (p < 0.001). Applying the other definitions led to higher percentages of advanced BC being detected. Depending on the definition interval, non-screened BCs had a 2â5-times risk of being advanced. Conclusion: Irrespective of the definition, screen-detected BCs were less frequently in the advanced stage. These findings provide evidence of a stage shift to early detection and support the potential of mammographic screening to reduce treatment-related burdens and the mortality associated with BC
WS1.1 The effect of ivacaftor, a CFTR potentiator, in patients with cystic fibrosis and a non-G551D-CFTR gating mutation, the KONNECTION study
The method of detection of ductal carcinoma in situ has no therapeutic implications: results of a population-based cohort study
Multivariable-adjusted Cox regression analysis of ipsilateral and contralateral invasive breast cancer in women aged 49â75 years at DCIS diagnosis (DCIS diagnostic period 1989â2004). Age was the primary time scale, time since DCIS diagnosis (0â5, 5â10, and â„10Â years) the secondary time scale, and DCIS treatment a time-varying covariable (DOCX 22 kb
Spherical harmonic decomposition applied to spatial-temporal analysis of human high-density EEG
We demonstrate an application of spherical harmonic decomposition to analysis
of the human electroencephalogram (EEG). We implement two methods and discuss
issues specific to analysis of hemispherical, irregularly sampled data.
Performance of the methods and spatial sampling requirements are quantified
using simulated data. The analysis is applied to experimental EEG data,
confirming earlier reports of an approximate frequency-wavenumber relationship
in some bands.Comment: 12 pages, 8 figures, submitted to Phys. Rev. E, uses APS RevTeX
style
Impact of Older Age and Comorbidity on Locoregional and Distant Breast Cancer Recurrence:A Large PopulationâBased Study
- âŠ