15 research outputs found
Funneling Light Through a Subwavelength Aperture with Epsilon-Near-Zero Materials
Integration of the next generation of photonic structures with electronic and
optical on-chip components requires the development of effective methods for
confining and controlling light in subwavelength volumes. Several techniques
enabling light coupling to sub-wavelength objects have recently been proposed,
including grating-, and composite-based solutions. However, experi-mental
realization of these couplers involves complex fabrication with \sim 10nm
resolution in three dimensions. One promising alternative to complex coupling
structures involves materials with vanishingly small dielectric permittivity,
also known as epsilon-near-zero (ENZ) materials. In contrast to the previously
referenced approaches, a single at layer of ENZ-material is expected to provide
effcient coupling between free-space radiation and sub-wavelength guiding
structures. Here we report the first direct observation of bulk-ENZ-enhanced
transmission through a subwavelength slit, accompanied by a theoretical study
of this phenomenon. Our study opens the door to multiple practical applications
of ENZ materials and ENZ-based photonic systems
Geckos decouple fore- and hind limb kinematics in response to changes in incline
This work is supported by an NSF grant (NSF IOS-1147043) to TE
Consent for brain tissue donation after intracerebral haemorrhage: a community-based study
BACKGROUND:Spontaneous intracerebral haemorrhage is a devastating form of stroke and its incidence increases with age. Obtaining brain tissue following intracerebral haemorrhage helps to understand its cause. Given declining autopsy rates worldwide, the feasibility of establishing an autopsy-based collection and its generalisability are uncertain. METHODS:We used multiple overlapping sources of case ascertainment to identify every adult diagnosed with intracerebral haemorrhage between 1st June 2010-31st May 2012, whilst resident in the Lothian region of Scotland. We sought consent from patients with intracerebral haemorrhage (or their nearest relative if the patient lacked mental capacity) to conduct a research autopsy. RESULTS:Of 295 adults with acute intracerebral haemorrhage, 110 (37%) could not be approached to consider donation. Of 185 adults/relatives approached, 91 (49%) consented to research autopsy. There were no differences in baseline demographic variables or markers of intracerebral haemorrhage severity between consenters and non-consenters. Adults who died and became donors (n = 46) differed from the rest of the cohort (n = 249) by being older (median age 80, IQR 76-86 vs. 75, IQR 65-83, p = 0.002) and having larger haemorrhages (median volume 23 ml, IQR 13-50 vs. 13 ml, IQR 4-40; p = 0.002). CONCLUSIONS:Nearly half of those approached consent to brain tissue donation after acute intracerebral haemorrhage. The characteristics of adults who gave consent were comparable to those in an entire community, although those who donate early are older and have larger haemorrhage volumes