Light Collimation and Focussing by a Thin Flat Metallic Slab

We present experimental and theoretical work showing that a flat metallic slab can collimate and focus light impinging on the slab from a punctual source. The effect is optimised when the radiation is around the bulk, not at the surface, plasma frequency. And the smaller the imaginary part of the permittivity is, the better the collimation. Experiments for Ag in the visible as well as calculations are presented. We also discuss the interesting case of the Aluminium whose imaginary part of the permittivity is very small at the plasma frequency in UV radiation. Generalization to other materials and radiations are also discussed.Comment: 6 pages, 3 figures. To be published on Optics Lette

Engineering physiological environments to advance kidney organoid models from human pluripotent stem cells

During embryogenesis, the mammalian kidney arises because of reciprocal interactions between the ureteric bud (UB) and the metanephric mesenchyme (MM), driving UB branching and nephron induction. These morphogenetic processes involve a series of cellular rearrangements that are tightly controlled by gene regulatory networks and signaling cascades. Here, we discuss how kidney developmental studies have informed the definition of procedures to obtain kidney organoids from human pluripotent stem cells (hPSCs). Moreover, bioengineering techniques have emerged as potential solutions to externally impose controlled microenvironments for organoid generation from hPSCs. Next, we summarize some of these advances with major focus On recent works merging hPSC-derived kidney organoids (hPSC-kidney organoids) with organ-on-chip to develop robust models for drug discovery and disease modeling applications. We foresee that, in the near future, coupling of different organoid models through bioengineering approaches will help advancing to recreate organ-to-organ crosstalk to increase our understanding on kidney disease progression in the human context and search for new therapeutics

Fiber sensors for the high-speed railway environment

Specialty Optical Fibers 2014, Barcelona, Spain, 27–31 July 2014We review some recent work on fiber-optic sensors for the high-speed railway environment. In particular, we show convenient fiber-optic solutions for rail and wheel monitoring, perimeter security and catenary protection in changeover section

Effect of extended short-circuiting in proton exchange membrane fuel cells

Short-circuiting is regularly utilized in Proton Exchange Membrane Fuel Cells (PEMFCs) to reverse short-term reversible catalyst degradation. However, do these improvements in fuel cell performance and durability still exist after extended operation? We provide an answer to this question by comparing the performance and durability of a PEMFC under open-circuit voltage (OCV) and a commercial short-circuiting protocol, against a PEMFC under OCV without short-circuiting for the same extended period (∼144 h). The experimental results demonstrate the detrimental effect of extended short-circuiting on the durability of the catalyst and the performance of the fuel cell. Electrochemically active surface area losses reach ∼46% for the short-circuiting case, compared to only ∼18% losses for the OCV without short-circuiting. TEM and XPS measurements are employed to monitor the morphological changes of the catalyst layer, revealing that Ostwald ripening, carbon corrosion, and Pt migration and precipitation into the polymer membrane are the main degradation mechanisms of the cathode catalyst layer. At the end of PEMFC operation, XPS measurements reveal that only ∼0.1% (atomic) of Pt remains on the surface of the cathode catalyst layer after OCV with short-circuiting, compared to the initial ∼0.4% Pt of the unused cathode MEA and ∼0.3% Pt for the cathode MEA after OCV without short-circuiting. These results show that short-circuiting can cause facile degradation of the catalyst layer and significant decrease in fuel cell performance, rendering this technique non-beneficial for extended operation

Análisis del efecto de materiales de cambio de fase sobre la demanda de calefacción en una casa fotovoltaica

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: Este trabajo evalúa el efecto que tiene la integración de materiales de cambio de fase (MCF) en la envolvente de los edificios, sobre la operación de un sistema de generación solar fotovoltaica acoplado con bomba de calor para cubrir las necesidades térmicas de dicho edificio. A partir de una instalación a escala real, se han realizado modelos en EnergyPlus de diferentes escenarios de estudio intermedios, teniendo en cuenta que la aplicación de los MCF microencapsulados como revestimiento de paredes interiores, requiere de un material de sustrato y un mortero para que se incorpore, evaluando de esta forma el efecto que tiene cada uno de los elementos. Se ha simulado y evaluado el efecto en cada escenario de estudio sobre la demanda energética del demostrador, desde la solución constructiva del fabricante hasta la solución con el mortero aditivado con MCF aplicado como recubrimiento interior de las paredes. En paralelo se ha realizado la simulación mediante TRNSYS de una instalación fotovoltaica de 50, 100, 200 y 300 W conectadas a una bomba de calor sobre la que se ha considerado que tiene un rendimiento en calefacción de 3 y un rendimiento de refrigeración de 2. Los resultados muestran que hay una gran cantidad de energía de calefacción que se pierde en los momentos en los que la demanda de calefacción es reducida y la disponibilidad de energía solar es alta. También se ha podido comprobar que el dimensionado para refrigeración es más crítico que para calefacción. Finalmente cabe indicar que el presente trabajo se ha realizado dentro del marco del proyecto SUDOKET financiado por la convocatoria Interreg SUDOE.ABSTRACT: The present work evaluates the effect that the incorporation of Phase Change Materials (PCM) in the building envelope has in the operation of a solar photovoltaic (PV) generation system coupled with a heat pump for covering the thermal demand of a building. Based on data from a real scale facility, the EnergyPlus models of different case scenarios have been performed, taking into account that the application of microencapsulated PCM as an interior wall coating requires a substrate material and a mortar matrix to be embedded into. The effect on each case scenario on the buildings energy demand, from the manufacturer constructive walls solution until the PCM enhanced mortar applied as the interior wall coating, has been simulated and evaluated. In parallel, the TRNSYS simulation of a solar photovoltaic (PV) system has been performed, considering 50, 100, 200 and 300 W connected to a heat pump with a heating performance of 3 and a cooling performance of 2. The obtained results show that there is a large amount of heating energy that is wasted when the demand for heating is low and the availability of solar energy is high. It has also been demonstrated that sizing for cooling is more critical than for heating. Finally, it should be indicated that this work has been carried out within the SUDOKET project financed by the Interreg SUDOE programme.info:eu-repo/semantics/publishedVersio

Direct determination of a low-pass components of a band-pass signal from samples of it and delayed versions of it

Peer ReviewedPostprint (published version

Nanomechanical Phenotypes in Cardiac Myosin-Binding Protein C Mutants That Cause Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a disease of the myocardium caused by mutations in sarcomeric proteins with mechanical roles, such as the molecular motor myosin. Around half of the HCM-causing genetic variants target contraction modulator cardiac myosin-binding protein C (cMyBP-C), although the underlying pathogenic mechanisms remain unclear since many of these mutations cause no alterations in protein structure and stability. As an alternative pathomechanism, here we have examined whether pathogenic mutations perturb the nanomechanics of cMyBP-C, which would compromise its modulatory mechanical tethers across sliding actomyosin filaments. Using single-molecule atomic force spectroscopy, we have quantified mechanical folding and unfolding transitions in cMyBP-C domains targeted by HCM mutations that do not induce RNA splicing alterations or protein thermodynamic destabilization. Our results show that domains containing mutation R495W are mechanically weaker than wild-type at forces below 40 pN and that R502Q mutant domains fold faster than wild-type. None of these alterations are found in control, nonpathogenic variants, suggesting that nanomechanical phenotypes induced by pathogenic cMyBP-C mutations contribute to HCM development. We propose that mutation-induced nanomechanical alterations may be common in mechanical proteins involved in human pathologies.J.A.C. acknowledges funding from the Ministerio de Ciencia e Innovación (MCIN) through grants BIO2014– 54768-P, BIO2017–83640-P (AEI/FEDER, UE), EIN2019–102966, RYC-2014–16604, and BFU2017–90692­ REDT, the European Research Area Network on Cardiovascular Diseases (ERA-CVD/ISCIII, MINOTAUR, AC16/00045), and the Comunidad de Madrid (consortium Tec4Bio-CM, S2018/NMT-4443, FEDER). This work was supported by NIH grants RM1 GM33289 and HL117138 to J.A.S.; a Stanford Dean’s Postdoctoral Fellowship to D.P. and N.N.; and a Stanford Maternal and Child Health Research Institute (MCHRI) Postdoctoral Fellowship (1220552–140-DHPEU) to N.N. Financial support to D.D.S. comes from Eusko Jaurlaritza (Basque Government) through the project IT1254–19, and grants RYC-2016–19590 and PGC2018–099321-B-I00 from the MCIN (FEDER). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), MCIN, and the Pro CNIC Foundation and was a Severo Ochoa Center of Excellence (SEV-2015–0505). We acknowledge funding from ISCIII to the Centro de Investigación Biomédica en Red (CIBERCV), CB16/11/00425. C.S.C. is the recipient of an FPI-SO predoctoral fellowship, BES-2016–076638. M.R.P. was the recipient of a Ph.D. fellowship from the Italian Ministry of Education, Universities and Research (MIUR). C.P.L. was a recipient of a CNIC Master Fellowship. We thank N. Vicente for excellent technical support (through grant PEJ16/MED/TL-1593 from Consejería de Educación, Juventud y Deporte de la Comunidad de Madrid and the European Social Fund). We thank the Spectroscopy and Nuclear Magnetic Resonance Core Unit at CNIO for access to CD instrumentation and discussion about protein binding assays. We thank A. Thompson and S. Day for their insights. We thank all members of the Molecular Mechanics of the Cardiovascular System team for helpful discussions and the contribution of five anonymous reviewers.S

Extending the Real Remoteness of Long-Range Brillouin Optical Time-Domain Fiber Analyzers

The real remoteness of a distributed optical fiber sensor based on Brillouin optical time-domain analysis is considerably extended in this paper using seeded second-order Raman amplification and optical pulse coding. The presented analysis and the experimental results demonstrate that a proper optimization of both methods combined with a well-equalized two-sideband probe wave provide a suitable solution to enhance the signal-to-noise ratio of the measurements when an ultra-long sensing fiber is used. In particular, the implemented system is based on an extended optical fiber length, in which half of the fiber is used for sensing purposes, and the other half is used to carry the optical signals to the most distant sensing point, providing also a long fiber for distributed Raman amplification. Power levels of all signals launched into the fiber are properly optimized in order to avoid nonlinear effects, pump depletion, and especially any power imbalance between the two sidebands of the probe wave. This last issue turns out to be extremely important in ultra-long Brillouin sensing to provide strong robustness of the system against pump depletion. This way, by employing a 240 km-long optical fiber-loop, sensing from the interrogation unit up to a 120 km remote position (i.e., corresponding to the real sensing distance away from the sensor unit) is experimentally demonstrated with a spatial resolution of 5 m. Furthermore, this implementation requires no powered element in the whole 240 km fiber loop, providing considerable advantages in situations where the sensing cable crosses large unmanned areas

Líneas de investigación experimentales del grupo de dinámica no lineal y fibras ópticas del Instituto de Óptica "Daza de Valdes del CSIC"

Se presenta y describen las líneas de trabajo experimentales que se vienen cultivando en el Grupo de investigación en Dinámica no Lineal y Fibras ópticas, recientemente creado en el Instituto de Óptica del CSIC. We present the experimental lines developed in last years in the Nonlinear Dynamics and Fiber Optics Group (NDFO) of the Optics Institute "Daza de Valdés" (IO-CSIC)

Germline sequence variants in TGM3 and RGS22 confer risk of basal cell carcinoma.

To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field.To search for new sequence variants that confer risk of cutaneous basal cell carcinoma (BCC), we conducted a genome-wide association study of 38.5 million single nucleotide polymorphisms (SNPs) and small indels identified through whole-genome sequencing of 2230 Icelanders. We imputed genotypes for 4208 BCC patients and 109 408 controls using Illumina SNP chip typing data, carried out association tests and replicated the findings in independent population samples. We found new BCC susceptibility loci at TGM3 (rs214782[G], P = 5.5 × 10(-17), OR = 1.29) and RGS22 (rs7006527[C], P = 8.7 × 10(-13), OR = 0.77). TGM3 encodes transglutaminase type 3, which plays a key role in production of the cornified envelope during epidermal differentiation.Red Tematica de Investigacion Cooperative en Cancer RD06/0020/1054 Danish Cancer Society "Europe Against Cancer": European Prospective Investigation into Cancer and Nutrition (EPIC) deCODE Genetics/AMGE