16 research outputs found
Spectroscopic scanning tunneling microscopy insights into Fe-based superconductors
In the first three years since the discovery of Fe-based high Tc
superconductors, scanning tunneling microscopy (STM) and spectroscopy have shed
light on three important questions. First, STM has demonstrated the complexity
of the pairing symmetry in Fe-based materials. Phase-sensitive quasiparticle
interference (QPI) imaging and low temperature spectroscopy have shown that the
pairing order parameter varies from nodal to nodeless s\pm within a single
family, FeTe1-xSex. Second, STM has imaged C4 -> C2 symmetry breaking in the
electronic states of both parent and superconducting materials. As a local
probe, STM is in a strong position to understand the interactions between these
broken symmetry states and superconductivity. Finally, STM has been used to
image the vortex state, giving insights into the technical problem of vortex
pinning, and the fundamental problem of the competing states introduced when
superconductivity is locally quenched by a magnetic field. Here we give a
pedagogical introduction to STM and QPI imaging, discuss the specific
challenges associated with extracting bulk properties from the study of
surfaces, and report on progress made in understanding Fe-based superconductors
using STM techniques.Comment: 36 pages, 23 figures, 229 reference
HEMODYNAMIC AND STRUCTURAL MODIFICATIONS IN CONTINUOUS INFUSION WITH ANGIOTENSIN. II. AN EXPERIMENTAL STUDY
The renin-angiotensin-aldosterone system (RAAS) is
a hormonal system which contributes to the regulation of
both arterial pressure and extra cellular fluids volume.
The increase of RAAS, especially at angiotensin II (Ang
II) level, affects the target organs and increases the risk of
cardio-vascular issues, by increasing arterial pressure and
through the direct effect of Ang II upon the vascular endothelium
and the renal and cardiac tissue. Ang II reduces
the renal capacity of sodium excretion and initiates
a set of events which increase arterial pressure. Increase
of arterial pressure is necessary for re-establishing sodium
excretion, being realized by the pressure-natriuresis
relationship. Arterial hypertension affects the target
organs (heart, kidneys) and leads to a vicious circle which
contributes to maintaining a high arterial pressure.
Materials and Method: Male Wistar rats subjected on
a normal diet, received either a sham operation (n=9) or
continuous angiotensin II (Ang II) infusion (300ng/kgc/
min) subcutaneously, via mini pumps. Water ingestion
and systolic blood pressure were measured for 14 days,
after which the animals were sacrificed under anesthesia
with ketamin, and the xylasin body weight, water ingestion,
heart mass, right and left ventricular mass, right
and left kidney mass were measured.
Results: After 14 days of Ang II infusion, bodily
weight decreased, systolic blood pressure increased, heart
and left ventricular mass indexed to body weight were
significantly enhanced compared with the sham group,
and kidneys mass indexed to body weight was similar in
the two groups
Supplement 1. SEM micrographs of the scent gland channel of Dysodius lunatus’ cuticle under the wing. In the left column of the figure, several images are stitched together showing the whole channel length with the three liquid secreting pores (indicated by white arrows). The middle and the right column show magnified details with oriented pointed microstructures. from Bioinspired polymer microstructures for directional transport of oily liquids
Nature has always served as an inspiration for scientists, helping them to solve a large diversity of technical problems. In our case, we are interested in the directional transport of oily liquids and as a role model for this application we used the flat bug <i>Dysodius lunatus</i>. In this report, we present arrays of drops looking like polymer microstructures produced by the two-photon polymerization technique that mimic the micro-ornamentation from the bug's cuticle. A good directionality of oil transport was achieved, directly controlled by the direction of the pointed microstructures at the surface. If the tips of the drop-like microstructures are pointing towards the left side, the liquid front moves to the right and vice versa. Similar effects could be expected for the transport of oily lubricants. These results could, therefore, be interesting for applications in friction and wear reduction
Supplement 3. Video of oily liquid dynamics on the polymer microstructures array (tips oriented to the right) enclosed in between the glass slide and the cover slip. The video is speeded up 10 times. from Bioinspired polymer microstructures for directional transport of oily liquids
Nature has always served as an inspiration for scientists, helping them to solve a large diversity of technical problems. In our case, we are interested in the directional transport of oily liquids and as a role model for this application we used the flat bug <i>Dysodius lunatus</i>. In this report, we present arrays of drops looking like polymer microstructures produced by the two-photon polymerization technique that mimic the micro-ornamentation from the bug's cuticle. A good directionality of oil transport was achieved, directly controlled by the direction of the pointed microstructures at the surface. If the tips of the drop-like microstructures are pointing towards the left side, the liquid front moves to the right and vice versa. Similar effects could be expected for the transport of oily lubricants. These results could, therefore, be interesting for applications in friction and wear reduction