70 research outputs found
Daily Objective Physical Activity and Sedentary Time in Adults with COPD Using Spirometry Data from Canadian Measures Health Survey
Chronic obstructive pulmonary disease (COPD) is expected to be the third leading cause of premature death and disability in Canada and around the world by the year 2020. The study aims to compare objective physical activity (PA) and sedentary time in a population-based sample of adults with chronic obstructive pulmonary disease (COPD) and compare a group, and to investigate whether these behaviors differ according to COPD severity. From the 2007â2013 Canadian Health Measures Survey dataset, accelerometer and prebronchodilator spirometry data were available for 6441 participants, aged 35 to 79. Two weighted analyses of covariance were performed with adjustments for age, sex, body mass index, accelerometer wearing time, season, work, smoking (cotinine), education level, and income. A set of sensitivity analyses were carried out to examine the possible effect of COPD and type of control group. A cross-sectional weighted analysis indicated that 14.6% of study participants had a measured airflow obstruction consistent with COPD. Time in PA (moderate-vigorous and light PA), number of steps, and sedentary duration were not significantly different in participants with COPD, taken together, compared to controls. However, moderate to severe COPD participants (stages â„2) had a significantly lower daily time spent in PA of moderate and vigorous intensity level compared to controls. Canadian adults with COPD with all disease severity levels combined did not show lower daily duration of light, moderate, and vigorous PA, and number of steps and higher daily sedentary time than those without airflow obstruction. Both groups are extremely sedentary and have low PA duration. Thus, âmove more and sit lessâ public health strategy could equally target adults with or without COPD
Volume intensified dilution of a ringâclosing metathesis in ethyl acetate by means of a membraneâassisted process in solvent recycle
Computational Methods Enable the Prediction of Improved Catalysts for Nickel-Catalyzed Cross-Electrophile Coupling
Cross-electrophile coupling has emerged as an attractive
and efficient
method for the synthesis of C(sp2)âC(sp3) bonds. These reactions are most often catalyzed by nickel complexes
of nitrogenous ligands, especially 2,2âČ-bipyridines. Precise
prediction, selection, and design of optimal ligands remains challenging,
despite significant increases in reaction scope and mechanistic understanding.
Molecular parameterization and statistical modeling provide a path
to the development of improved bipyridine ligands that will enhance
the selectivity of existing reactions and broaden the scope of electrophiles
that can be coupled. Herein, we describe the generation of a computational
ligand library, correlation of observed reaction outcomes with features
of the ligands, and the in silico design of improved bipyridine ligands
for Ni-catalyzed cross-electrophile coupling. The new nitrogen-substituted
ligands display a 5-fold increase in selectivity for product formation
versus homodimerization when compared to the current state of the
art. This increase in selectivity and yield was general for several
cross-electrophile couplings, including the challenging coupling of
an aryl chloride with an N-alkylpyridinium salt
Computational Methods Enable the Prediction of Improved Catalysts for Nickel-Catalyzed Cross-Electrophile Coupling
Cross-electrophile coupling has emerged as an attractive
and efficient
method for the synthesis of C(sp2)âC(sp3) bonds. These reactions are most often catalyzed by nickel complexes
of nitrogenous ligands, especially 2,2âČ-bipyridines. Precise
prediction, selection, and design of optimal ligands remains challenging,
despite significant increases in reaction scope and mechanistic understanding.
Molecular parameterization and statistical modeling provide a path
to the development of improved bipyridine ligands that will enhance
the selectivity of existing reactions and broaden the scope of electrophiles
that can be coupled. Herein, we describe the generation of a computational
ligand library, correlation of observed reaction outcomes with features
of the ligands, and the in silico design of improved bipyridine ligands
for Ni-catalyzed cross-electrophile coupling. The new nitrogen-substituted
ligands display a 5-fold increase in selectivity for product formation
versus homodimerization when compared to the current state of the
art. This increase in selectivity and yield was general for several
cross-electrophile couplings, including the challenging coupling of
an aryl chloride with an N-alkylpyridinium salt
Computational Methods Enable the Prediction of Improved Catalysts for Nickel-Catalyzed Cross-Electrophile Coupling
Cross-electrophile coupling has emerged as an attractive
and efficient
method for the synthesis of C(sp2)âC(sp3) bonds. These reactions are most often catalyzed by nickel complexes
of nitrogenous ligands, especially 2,2âČ-bipyridines. Precise
prediction, selection, and design of optimal ligands remains challenging,
despite significant increases in reaction scope and mechanistic understanding.
Molecular parameterization and statistical modeling provide a path
to the development of improved bipyridine ligands that will enhance
the selectivity of existing reactions and broaden the scope of electrophiles
that can be coupled. Herein, we describe the generation of a computational
ligand library, correlation of observed reaction outcomes with features
of the ligands, and the in silico design of improved bipyridine ligands
for Ni-catalyzed cross-electrophile coupling. The new nitrogen-substituted
ligands display a 5-fold increase in selectivity for product formation
versus homodimerization when compared to the current state of the
art. This increase in selectivity and yield was general for several
cross-electrophile couplings, including the challenging coupling of
an aryl chloride with an N-alkylpyridinium salt
Computational Methods Enable the Prediction of Improved Catalysts for Nickel-Catalyzed Cross-Electrophile Coupling
Cross-electrophile coupling has emerged as an attractive
and efficient
method for the synthesis of C(sp2)âC(sp3) bonds. These reactions are most often catalyzed by nickel complexes
of nitrogenous ligands, especially 2,2âČ-bipyridines. Precise
prediction, selection, and design of optimal ligands remains challenging,
despite significant increases in reaction scope and mechanistic understanding.
Molecular parameterization and statistical modeling provide a path
to the development of improved bipyridine ligands that will enhance
the selectivity of existing reactions and broaden the scope of electrophiles
that can be coupled. Herein, we describe the generation of a computational
ligand library, correlation of observed reaction outcomes with features
of the ligands, and the in silico design of improved bipyridine ligands
for Ni-catalyzed cross-electrophile coupling. The new nitrogen-substituted
ligands display a 5-fold increase in selectivity for product formation
versus homodimerization when compared to the current state of the
art. This increase in selectivity and yield was general for several
cross-electrophile couplings, including the challenging coupling of
an aryl chloride with an N-alkylpyridinium salt
Three-month neoadjuvant hormonal therapy before radical prostatectomy: a 7-year follow-up of a randomized controlled trial
- âŠ