22 research outputs found
Engineering conductive protein films through nanoscale self-assembly and gold nanoparticles doping
This work was partially supported by the European Research
Council ERC-CoG-648071-ProNANO, ERC-PoC-841063-NIMM,
Agencia Estatal de Investigación, Spain (PID2019-
111649RB-I00; and MAT2017-88693-R), and the Basque
Government (Elkartek KK-2017/00008), E.L-M thanks the
Spanish Ministry of Science and Innovation for the FPI grant
(BES-2017-079646). This work was performed under the Maria
de Maeztu Units of Excellence Program from the Spanish State
Research Agency – Grant No. MDM-2017-0720 (CIC
biomaGUNE) and SEV-2016-0686 (IMDEA Nanociencia).Protein-based materials are usually considered as insulators, although conductivity has been recently shown in proteins. This fact opens the door to develop new biocompatible conductive materials. While there are emerging efforts in this area, there is an open challenge related to the limited conductivity of protein-based systems. This work shows a novel approach to tune the charge transport properties of protein-based materials by using electron-dense AuNPs. Two strategies are combined in a unique way to generate the conductive solid films: (1) the controlled self-assembly of a protein building block; (2) the templating of AuNPs by the engineered building block. This bottom-up approach allows controlling the structure of the films and the distribution of the AuNPs within, leading to enhanced conductivity. This work illustrates a promising strategy for the development of effective hybrid protein-based bioelectrical materials.European Research Council (ERC)
European Commission
ERC-CoG-648071-ProNANO
ERC-PoC-841063-NIMMAgencia Estatal de Investigacion, Spain
PID2019111649RB-I00
MAT2017-88693-RBasque Government
Elkartek KK-2017/00008Spanish Government
BES-2017-079646Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency
MDM-2017-0720
SEV-2016-068
Repeat protein scaffolds: ordering photo- and electroactive molecules in solution and solid state
The precise control over the organization of photoactive components at the nanoscale is one of the main challenges for the generation of new and sophisticated macroscopically ordered materials with enhanced properties. In this work we present a novel bioinspired approach using protein-based building blocks for the arrangement of photo and electroactive porphyrin
derivatives. We used a designed repeat protein scaffold with demonstrated unique features that allow for the control of their structure, functionality, and assembly. Our designed domains act as exact biomolecular templates to organize porphyrin molecules at the required distance. The hybrid conjugates retain the structure and assembly properties of the protein scaffold and display the spectroscopic features of orderly aggregated porphyrins along the protein structure. Finally,we achieved a solid ordered bio-organic hybrid thin film with anisotropic photoconductivity
Protein-directed crystalline 2D fullerene assemblies
Water soluble 2D crystalline monolayers of fullerenes grow on planar assemblies of engineered consensus tetratricopeptide repeat proteins. Designed fullerene-coordinating tyrosine clamps on the protein introduce specific fullerene binding sites, which facilitate fullerene nucleation. Through reciprocal interactions between the components, the hybrid material assembles into two-dimensional 2 nm thick structures with crystalline order, that conduct photo-generated charges. Thus, the protein-fullerene hybrid material is a demonstration of the developments toward functional materials with protein-based precision control of functional elements
Association of HLA-B*41:02 with Henoch-Schönlein Purpura (IgA Vasculitis) in Spanish individuals irrespective of the HLA-DRB1 status
Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU
Contains fulltext :
172380.pdf (publisher's version ) (Open Access
Broadband multi-wavelength properties of M87 during the 2017 Event Horizon Telescope campaign
In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the
center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations
for a weakly accreting supermassive black hole of mass ∼6.5 × 109Me. The EHTC also partnered with several
international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength
campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a
legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at
high energies, making it possible to combine core flux constraints with the more spatially precise very long
baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active
nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one
broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the
basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude
that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the
EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of
HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and
secondaries cannot yet be excluded.http://iopscience.iop.org/2041-8205am2022Physic
The Polarized Image of a Synchrotron-emitting Ring of Gas Orbiting a Black Hole
Abstract: Synchrotron radiation from hot gas near a black hole results in a polarized image. The image polarization is determined by effects including the orientation of the magnetic field in the emitting region, relativistic motion of the gas, strong gravitational lensing by the black hole, and parallel transport in the curved spacetime. We explore these effects using a simple model of an axisymmetric, equatorial accretion disk around a Schwarzschild black hole. By using an approximate expression for the null geodesics derived by Beloborodov and conservation of the Walker–Penrose constant, we provide analytic estimates for the image polarization. We test this model using currently favored general relativistic magnetohydrodynamic simulations of M87*, using ring parameters given by the simulations. For a subset of these with modest Faraday effects, we show that the ring model broadly reproduces the polarimetric image morphology. Our model also predicts the polarization evolution for compact flaring regions, such as those observed from Sgr A* with GRAVITY. With suitably chosen parameters, our simple model can reproduce the EVPA pattern and relative polarized intensity in Event Horizon Telescope images of M87*. Under the physically motivated assumption that the magnetic field trails the fluid velocity, this comparison is consistent with the clockwise rotation inferred from total intensity images
The polarized image of a synchrotron-emitting ring of gas orbiting a black hole
Synchrotron radiation from hot gas near a black hole results in a polarized image. The image polarization is
determined by effects including the orientation of the magnetic field in the emitting region, relativistic motion of
the gas, strong gravitational lensing by the black hole, and parallel transport in the curved spacetime. We explore
these effects using a simple model of an axisymmetric, equatorial accretion disk around a Schwarzschild black
hole. By using an approximate expression for the null geodesics derived by Beloborodov and conservation of the
Walker–Penrose constant, we provide analytic estimates for the image polarization. We test this model using
currently favored general relativistic magnetohydrodynamic simulations of M87*, using ring parameters given by
the simulations. For a subset of these with modest Faraday effects, we show that the ring model broadly reproduces
the polarimetric image morphology. Our model also predicts the polarization evolution for compact flaring regions,
such as those observed from Sgr A* with GRAVITY. With suitably chosen parameters, our simple model can
reproduce the EVPA pattern and relative polarized intensity in Event Horizon Telescope images of M87*. Under
the physically motivated assumption that the magnetic field trails the fluid velocity, this comparison is consistent
with the clockwise rotation inferred from total intensity images.http://iopscience.iop.org/0004-637Xam2023Physic
First M87 Event Horizon Telescope Results. VII. Polarization of the Ring
Abstract: In 2017 April, the Event Horizon Telescope (EHT) observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy. These 1.3 mm wavelength observations revealed a compact asymmetric ring-like source morphology. This structure originates from synchrotron emission produced by relativistic plasma located in the immediate vicinity of the black hole. Here we present the corresponding linear-polarimetric EHT images of the center of M87. We find that only a part of the ring is significantly polarized. The resolved fractional linear polarization has a maximum located in the southwest part of the ring, where it rises to the level of ∼15%. The polarization position angles are arranged in a nearly azimuthal pattern. We perform quantitative measurements of relevant polarimetric properties of the compact emission and find evidence for the temporal evolution of the polarized source structure over one week of EHT observations. The details of the polarimetric data reduction and calibration methodology are provided. We carry out the data analysis using multiple independent imaging and modeling techniques, each of which is validated against a suite of synthetic data sets. The gross polarimetric structure and its apparent evolution with time are insensitive to the method used to reconstruct the image. These polarimetric images carry information about the structure of the magnetic fields responsible for the synchrotron emission. Their physical interpretation is discussed in an accompanying publication