300 research outputs found
Caveolae: Mechanosensing and mechanotransduction devices linking membrane trafficking to mechanoadaptation.
Mechanical forces (extracellular matrix stiffness, vascular shear stress, and muscle stretching) reaching the plasma membrane (PM) determine cell behavior. Caveolae are PM-invaginated nanodomains with specific lipid and protein composition. Being highly abundant in mechanically challenged tissues (muscles, lungs, vessels, and adipose tissues), they protect cells from mechanical stress damage. Caveolae flatten upon increased PM tension, enabling both force sensing and accommodation, critical for cell mechanoprotection and homeostasis. Thus, caveolae are highly plastic, ranging in complexity from flattened membranes to vacuolar invaginations surrounded by caveolae-rosettes-which also contribute to mechanoprotection. Caveolar components crosstalk with mechanotransduction pathways and recent studies show that they translocate from the PM to the nucleus to convey stress information. Furthermore, caveolae components can regulate membrane traffic from/to the PM to adapt to environmental mechanical forces. The interdependence between lipids and caveolae starts to be understood, and the relevance of caveolae-dependent membrane trafficking linked to mechanoadaption to different physiopathological processes is emerging.This study was supported by grants from the Spanish Ministry of Science and Innovation(MICIIN)/Agencia Estatal de Investigación (AEI)/European Regional Development Fund (ERDF/FEDER) “A way to make Europe” – (SAF2014-51876-R, SAF2017-83130-R, IGP-SO grant MINSEV1512-07-2016, CSD2009-0016 and BFU2016-81912-REDC), Comunidad Autónoma de Madrid (Tec4Bio-CM, S2018/NMT¬4443), Fundació La Marató de TV3 (385/C/2019) and the Worldwide Cancer Research Foundation (15-0404), all to M.A.d.P. We received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 641639. The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MICIIN) and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S
Water-Covered Roof Versus Inverted Flat Roof on the Mediterranean Coast: A Comparative Study of Thermal and Energy Behavior
Reservoir, or water-collecting roofs present greater thermal inertia than inverted flat roofs due to the mass of water they contain. This feature gives them better thermal performance and leads to greater stability in the indoor air temperature Ti and the wall surface temperatures. In the summer, they can dampen the effect of solar radiation and regulate external thermal loads thanks to their greater effusivity and thermal capacity. This research compares the thermal behavior of the roofs of two buildings located in Alicante on the Spanish Mediterranean coast: a loft flat in the city center and a water-covered roof in the Museum of the University of Alicante (MUA). Values for effusivity, diffusivity, thermal capacity, decrement factor, time lag and internal, as well as external thermal admittance were obtained. After monitoring both roofs during 2014, behavior simulations were performed in Design Builder using 6 different scenarios reflecting different combinations in both buildings of water-covered, inverted and conventional roofs and marble or terrazzo paving. The water-covered roof led to a higher decrement factor and time lag, as well as to a reduction of annual energy demands between 8.86% and 9.03%.This research was funded by the Vice-rectorate of Campus and Technology of the University of Alicante, in grants awarded by the Own Programme in 2014
Distrofia foveomacular viteliforme del adulto
Four cases of adult-onset foveomacular vitelliform dystrophy are shown. In two cases we were able to complete the exploration under optical coherence tomography. One of the patients developed spontaneous disappearance of the subfoveal deposit in her right eye along with an important decrease in her visual acuity.
Discussion: Adult-onset foveomacular vitelliform dystrophy is characterized by yellowish round-shaped bilateral, lesions in the subfoveal area. Optical coherence tomography reveal the presence of a slightly elevated lesion wich affects the retinal pigment epithelium and the external layers of neurosensory retin
Enhancement of nonlinear optical phenomena by localized resonances
Nonlinear optics at the nanoscale is severely limited by the small departure of available materials from linear behavior. Despite intense efforts placed into overcoming this problem using multiple strategies for enhancing the near-field light intensity, all-optical active nanodevices remain a challenge. Here we introduce a material-independent scheme for quantifying the enhancement of the nonlinear response in nanostructures assisted by proximal metallic or dielectric nanoresonators. The proposed figures of merit, which we apply to configurations of current interest incorporating 2D materials and dielectric cavities, can be generally used to optimize nonlinear nanoscale elements.Peer ReviewedPostprint (author's final draft
Amniotic membrane transplantation with fibrin glue as treatment of refractory conjunctivochalasis
Case report: A 63-year-old man with bilateral conjunctivochalasis
presented with tearing, irritation,
foreign body sensation and a delayed fluorescein
clearance test. After no symptomatic improvement
with topical treatment, surgery was carried out,
with amniotic membrane transplantation and fibrin
sealant.
Discussion: Conjunctivochalasis is a frequent
disorder that shares symptoms with dry eye syndrome.
When there is no response to topical treatment,
surgical treatment is needed. The surgical technique
described by Tseng, and based on amniotic membrane
transplantation without suture, resulted in a
very useful response, due to less inflammation and
a rapid resolution and improvement of symptom
Distrofia macular anular benigna
Clinical cases: Two cases of benign concentric macular dystrophy are described. In one case, ophthalmologic examination, fluorescein angiogram and visual field measurement were performed. The presence of a juxtafoveal fibrosis in the other patient, indicate that choroidal neovascularization may be associated with this type of macular dystrophy.
Discussion: Benign concentric macular dystrophy is an entity with well-defined ophthalmoscopic and angiographic characteristics. Usually the prognosis is good. Rarely, choroidal neovascularization can be associated with this macular dystroph
Theory of electron energy-loss spectroscopy in atomically thin metallic films
We study strongly confined plasmons in ultrathin gold and silver films by
simulating electron energy-loss spectroscopy (EELS). Plasmon dispersion
relations are directly retrieved from the energy- and momentum-resolved loss
probability under normal incidence conditions, whereas they can also be
inferred for aloof parallel beam trajectories from the evolution of the plasmon
features in the resulting loss spectra as we vary the impinging electron
energy. We find good agreement between nonlocal quantum-mechanical simulations
based on the random-phase approximation and a local classical dielectric
description for silver films of different thicknesses down to a few atomic
layers. We further observe only a minor dependence of quantum simulations for
these films on the confining out-of-plane electron potential when comparing
density-functional theory within the jellium model with a phenomenological
experimentally-fitted potential incorporating atomic layer periodicity and
in-plane parabolic bands of energy-dependent effective mass. The latter shows
also a small dependence on the crystallographic orientation of silver films,
while the unphysical assumption of energy-independent electron mass leads to
spurious features in the predicted spectra. Interestingly, we find electron
band effects to be more relevant in gold films, giving rise to blue shifts when
compared to classical or jellium model simulations. In contrast to the strong
nonlocal effects found in few-nanometer metal nanoparticles, our study reveals
that a local classical description provides excellent quantitative results in
both plasmon strength and dispersion when compared to quantum-mechanical
simulations down to silver films consisting of only a few atomic layers, thus
emphasizing the in-plane nearly-free conduction-electron motion associated with
plasmons in these structures.Comment: 15 pages, 13 figures, 76 reference
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