1,058 research outputs found
The relation between adult height and haemorrhagic and ischaemic stroke in the Renfrew/Paisley study
Adult height is a useful marker of fetal growth, growth and nutrition in childhood and childhood infections. Studies reporting inverse associations between height and stroke therefore provide support for the hypothesis that exposures acting in early life are important determinants of risk of stroke. However, few studies have been able to examine the association between height and stroke subtype. We recently showed that height is inversely related to ischaemic stroke, but because of small numbers it was not possible to robustly analyse the association between height and haemorrhagic stroke. A Norwegian study has shown a stronger inverse association with haemorrhagic compared with ischaemic stroke, but adjustment for socioeconomic position was not possible. We recently reported a significant inverse association between height and stroke mortality in both men and women in the Renfrew/Paisley cohort. Here we examine the association between height and subtype of incident stroke in this cohort
Kirigami Actuators
Thin elastic sheets bend easily and, if they are patterned with cuts, can
deform in sophisticated ways. Here we show that carefully tuning the location
and arrangement of cuts within thin sheets enables the design of mechanical
actuators that scale down to atomically-thin 2D materials. We first show that
by understanding the mechanics of a single, non-propagating crack in a sheet we
can generate four fundamental forms of linear actuation: roll, pitch, yaw, and
lift. Our analytical model shows that these deformations are only weakly
dependent on thickness, which we confirm with experiments at centimeter scale
objects and molecular dynamics simulations of graphene and MoS nanoscale
sheets. We show how the interactions between non-propagating cracks can enable
either lift or rotation, and we use a combination of experiments, theory,
continuum computational analysis, and molecular dynamics simulations to provide
mechanistic insights into the geometric and topological design of kirigami
actuators.Comment: Soft Matter, 201
Magnetization of undoped 2-leg S = 1/2 spin ladders in La4Sr10Cu24O41
Magnetization data of single crystalline La4Sr10Cu24O41 are presented. In
this compound, doped spin chains and undoped spin ladders are realized. The
magnetization, at low temperatures, is governed by the chain subsystem with a
finite interchain coupling which leads to short range antiferromagnetic spin
correlations. At higher temperatures, the response of the chains can be
estimated in terms of a Curie-Weiss law. For the ladders, we apply the
low-temperature approximation for a S=1/2 2-leg spin ladder by Troyer et al.Comment: 2 pages, 2 figure
Mechanisms of Electrical Conductivity in Y(1-x)CaxBa2Cu3O6.1 System
Systematic studies of transport properties in deoxygenated
Y(1-x)CaxBa2Cu3O6.1 series allowed to propose a diagram of conductivity
mechanisms for this system. At intermediate temperature a variable range
hopping (VRH) in 2 dimensions prevails. At lower temperature VRH in the
presence of a Coulomb gap for smaller x and VRH in 2 dimensions for larger x
are found. In a vicinity of superconductivity we observe conductivity
proportional to \sqrt{T}. Thermally activated conductivity dominates at higher
temperature. This diagram may be universal for the whole family of undoped high
Tc related cuprates.Comment: 5 page
- …