The
generation of tertiary, secondary, and primary alkyl radicals
has been achieved by the direct visible-light excitation of a boracene-based
alkylborate. This system is based on the photophysical properties
of the organoboron molecule. The protocol is applicable to decyanoalkylation,
Giese addition, and nickel-catalyzed carbon–carbon bond formations
such as alkyl–aryl cross-coupling or vicinal alkylarylation
of alkenes, enabling the introduction of various C(sp3)
fragments to organic molecules.
Radical–radical
coupling, the selective reaction between
two different radical species, has contributed to the methodology
for connecting bulky units. Light-driven N-heterocyclic
carbene (NHC) organocatalysis is recognized as a state-of-the-art
methodology enabling radical–radical coupling. The catalytic
process involves forming an acyl azolium intermediate from the NHC
catalyst and an acyl donor, followed by single electron reduction
of this key intermediate, which is largely dependent on the photoredox
catalyst. We designed a radical NHC catalysis in which the direct
photoexcitation of a borate to form a high reducing agent facilitated
the single electron reduction event. The borate produces an alkyl
radical for the single electron transfer process to accomplish the
radical–radical coupling. This protocol enables cross-coupling
between alkylborates and acyl imidazoles in addition to radical relay-type
alkylacylations of alkenes with alkylborates and acyl imidazoles,
affording ketones with a broad scope.
The boracene-based alkylborate enabled visible light-mediated metallaphotoredox catalysis. The directly excited borate was easily oxidatively quenched by the excited Ir photoredox catalyst. The Ni/Ir hybrid catalysis afforded the products under...
Concentration of myoglobin in serum was measured from 114 patients with acute cerebrovascular diseases and compared with serum creatine phosphokinase (CPK) and aldolase activities. The results obtained were as follows : (1) Elevated activity of myoglobin was observed in various types of stroke as well as CPK and aldolase. (2) The myoglobin level was significantly higher in patients with thalamic hemorrhage than in those with cortical infarction, while no difference was observed in other types of stroke. (3) The level of myoglobin was correlated well with the CPK level, but not with aldolase. (4) Correlation between myoglobin and level of consciousness was not observed. (5) No difference in myoglobin concentration in patients was observed between the died within four weeks and the survived. These results indicated that measurement of serum myoglobin in acute cerebrovascular diseases would not be useful for determining the type, severity and prognosis of the diseases.
Adults with cerebral palsy often use a cane as a walking aid because of their decreased gait ability. However, it is unclear whether this affects lower limb muscle activity during walking. The purpose of this study was to clarify the influence of using a cane during walking on the spatio-temporal parameters of walking, lower limb muscle activity, and lower limb muscle coactivation in adults with spastic cerebral palsy. [Participants and Methods] Eleven participants with cerebral palsy were included. The spatio-temporal parameters of walking, lower limb muscle activity, and coactivation of lower limb muscle were measured during a 10 m trial with no cane, one cane, and two canes. [Results] Walking speed was lower and the stride time longer when using two canes than when using no cane. All muscle activities significantly reduced when using two canes. No significant difference was observed between using no cane and one cane, except for walking speed. In addition, there was no significant difference in coactivation between the conditions. [Conclusion] This study revealed that when two canes were used, the walking speed was reduced, and lower limb muscle activity was reduced, reducing the burden. In contrast, the movement pattern was not suggested to have changed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.