Sensitive detection of voltage transients using differential intensity surface plasmon resonance system

This paper describes theoretical and experimental study of the fundamentals of using surface plasmon resonance (SPR) for label-free detection of voltage. Plasmonic voltage sensing relies on the capacitive properties of metal-electrolyte interface that are governed by electrostatic interactions between charge carriers in both phases. Externally-applied voltage leads to changes in the free electron density in the surface of the metal, shifting the SPR position. The study shows the effects of the applied voltage on the shape of the SPR curve. It also provides a comparison between the theoretical and experimental response to the applied voltage. The response is presented in a universal term that can be used to assess the voltage sensitivity of different SPR instruments. Finally, it demonstrates the capacity of the SPR system in resolving dynamic voltage signals; a detection limit of 10mV with a temporal resolution of 5ms is achievable. These findings pave the way for the use of SPR systems in the detection of electrical activity of biological cells

Protein crystals in adenovirus type 5-infected cells: requirements for intranuclear crystallogenesis, structural and functional analysis

Intranuclear crystalline inclusions have been observed in the nucleus of epithelial cells infected with Adenovirus serotype 5 (Ad5) at late steps of the virus life cycle. Using immuno-electron microscopy and confocal microscopy of cells infected with various Ad5 recombinants modified in their penton base or fiber domains, we found that these inclusions represented crystals of penton capsomers, the heteromeric capsid protein formed of penton base and fiber subunits. The occurrence of protein crystals within the nucleus of infected cells required the integrity of the fiber knob and part of the shaft domain. In the knob domain, the region overlapping residues 489–492 in the FG loop was found to be essential for crystal formation. In the shaft, a large deletion of repeats 4 to 16 had no detrimental effect on crystal inclusions, whereas deletion of repeats 8 to 21 abolished crystal formation without altering the level of fiber protein expression. This suggested a crucial role of the five penultimate repeats in the crystallisation process. Chimeric pentons made of Ad5 penton base and fiber domains from different serotypes were analyzed with respect to crystal formation. No crystal was found when fiber consisted of shaft (S) from Ad5 and knob (K) from Ad3 (heterotypic S5-K3 fiber), but occurred with homotypic S3K3 fiber. However, less regular crystals were observed with homotypic S35-K35 fiber. TB5, a monoclonal antibody directed against the Ad5 fiber knob was found by immunofluorescence microscopy to react with high efficiency with the intranuclear protein crystals in situ. Data obtained with Ad fiber mutants indicated that the absence of crystalline inclusions correlated with a lower infectivity and/or lower yields of virus progeny, suggesting that the protein crystals might be involved in virion assembly. Thus, we propose that TB5 staining of Ad-infected 293 cells can be used as a prognostic assay for the viability and productivity of fiber-modified Ad5 vectors

Interventions to promote cost-effectiveness in adult Intensive care units: consensus statement and considerations for best practice from a multidisciplinary and multinational eDelphi study

Background There is limited evidence to guide interventions that promote cost-effectiveness in adult intensive care units (ICU). The aim of this consensus statement is to identify globally applicable interventions for best ICU practice and provide guidance for judicious use of resources. Methods A three-round modified online Delphi process, using a web-based platform, sought consensus from 61 multidisciplinary ICU experts (physicians, nurses, allied health, administrators) from 21 countries. Round 1 was qualitative to ascertain opinions on cost-effectiveness criteria based on four key domains of high-value healthcare (foundational elements; infrastructure fundamentals; care delivery priorities; reliability and feedback). Round 2 was qualitative and quantitative, while round 3 was quantitative to reiterate and establish criteria. Both rounds 2 and 3 utilized a five-point Likert scale for voting. Consensus was considered when > 70% of the experts voted for a proposed intervention. Thereafter, the steering committee endorsed interventions that were identified as ‘critical’ by more than 50% of steering committee members. These interventions and experts’ comments were summarized as final considerations for best practice. Results At the conclusion of round 3, consensus was obtained on 50 best practice considerations for cost-effectiveness in adult ICU. Finally, the steering committee endorsed 9 ‘critical’ best practice considerations. This included adoption of a multidisciplinary ICU model of care, focus on staff training and competency assessment, ongoing quality audits, thus ensuring high quality of critical care services whether within or outside the four walls of ICUs, implementation of a dynamic staff roster, multidisciplinary approach to implementing end-of-life care, early mobilization and promoting international consensus efforts on the Green ICU concept. Conclusions This Delphi study with international experts resulted in 9 consensus statements and best practice considerations promoting cost-effectiveness in adult ICUs. Stakeholders (government bodies, professional societies) must lead the efforts to identify locally applicable specifics while working within these best practice considerations with the available resources

The cos 2 phi asymmetry of Drell-Yan and J/psi production in unpolarized ppbar scattering

We investigate the cos 2 phi azimuthal asymmetry in Drell--Yan and J/psi production from unpolarized ppbar scattering at GSI-HESR energies. The contribution to this asymmetry arising from the leading-twist Boer-Mulders function h_1^perp(x, k_T^2), which describes a correlation between the transverse momentum and the transverse spin of quarks in an unpolarized hadron, is explicitly evaluated, and predictions for the GSI-HESR kinematic regime are presented. We show that the cos 2 phi asymmetry is quite sizable both on the J/psi peak and in the Drell-Yan continuum region. Therefore these processes may offer an experimentally viable access to the Boer-Mulders function in the early unpolarized stage of GSI experiments.Comment: 5 pages, 3 figures, to be published in Eur. Phys.

Estudio de resistencia al desgaste y corrosión de recubrimientos de CrSiN sometidos a la acción de un fluido dinámico

Spa: El presente trabajo busca evaluar el comportamiento de recubrimientos de CrSiN depositados vía PVD sobre sustratos de acero API 5CT N80, sometidas a la acción de un fluido dinámico agresivo conformado por material particulado de alta dureza y baja solubilidad (sílice de tamaño de partícula entre 50 y 150 μm) y adición de NaCl, empleando las técnicas de Pin on Disc y Electrodo de Cilindro Rotatorio, con el fin de establecer su respuesta a los fenómenos de desgaste y corrosión, la cual estará soportada, para la última técnica por el análisis hidrodinámico del fluido (velocidad de rotación) y su relación con el comportamiento del material empleado, para ser utilizado como recubrimiento en sistemas de tuberías para instalaciones industriales de transporte de fluidos, buscando nuevas alternativas que permitan aumentar tanto la confiabilidad como la vida útil de estas instalaciones.DoctoradoDoctorado en Ingeniería y Ciencia de los Materiale

First Sagittarius A* Event Horizon Telescope Results. VII. Polarization of the Ring

The Event Horizon Telescope observed the horizon-scale synchrotron emission region around the Galactic center supermassive black hole, Sagittarius A* (Sgr A*), in 2017. These observations revealed a bright, thick ring morphology with a diameter of 51.8 ± 2.3 μas and modest azimuthal brightness asymmetry, consistent with the expected appearance of a black hole with mass M ≈ 4 × 106 M ⊙. From these observations, we present the first resolved linear and circular polarimetric images of Sgr A*. The linear polarization images demonstrate that the emission ring is highly polarized, exhibiting a prominent spiral electric vector polarization angle pattern with a peak fractional polarization of ∼40% in the western portion of the ring. The circular polarization images feature a modestly (∼5%–10%) polarized dipole structure along the emission ring, with negative circular polarization in the western region and positive circular polarization in the eastern region, although our methods exhibit stronger disagreement than for linear polarization. We analyze the data using multiple independent imaging and modeling methods, each of which is validated using a standardized suite of synthetic data sets. While the detailed spatial distribution of the linear polarization along the ring remains uncertain owing to the intrinsic variability of the source, the spiraling polarization structure is robust to methodological choices. The degree and orientation of the linear polarization provide stringent constraints for the black hole and its surrounding magnetic fields, which we discuss in an accompanying publication