Isotropic charged cosmologies in infrared-modified electrodynamics

It has long been known that the covariant formulation of quantum electrodynamics conflicts with the local description of states in the charged sector. Some of the solutions to this problem amount to modifications of the subsidiary conditions below some arbitrarily low photon frequency. Such infrared modified theories have been shown to be equivalent to standard Maxwell electrodynamics with an additional classical electromagnetic current induced by the quantum charges. The induced current only has support for very small frequencies and cancels the effects of the physical charges on large scales. In this work we explore the possibility that this de-electrification effect could allow for the existence of isotropic charged cosmologies, thus evading the stringent limits on the electric charge asymmetry of the universe. We consider a simple model of infrared-modified scalar electrodynamics in the cosmological context and find that the charged sector generates a new contribution to the energy-momentum tensor whose dominant contribution at late times is a cosmological constant-like term. If the charge asymmetry was generated during inflation, the limits on the asymmetry parameter in order not to produce a too-large cosmological constant are very stringent $\eta_Q <10^{-131}- 10^{-144}$ for a number of e-folds $N=50-60$ in typical models. However if the charge imbalance is produced after inflation, the limits are relaxed in such a way that \eta_Q<10^{-43}(100 \,\mbox{GeV}/T_Q), with $T_Q$ the temperature at which the asymmetry was generated. If the charge asymmetry has ever existed and the associated electromagnetic fields vanish in the asymptotic future, the limit can be further reduced to $\eta_Q<10^{-28}$.Comment: 10 pages, 6 figure

Cerebrospinal fluid shunting for the management of cryptococcal meningitis: a scoping review

Objective: This scoping review aimed to describe studies that evaluate the management of cryptococcal meningitis (CM) using cerebrospinal fluid (CSF) shunts, types of shunts used, and clinically relevant patient outcomes. Methods: We searched in the following databases: PubMed, Web of Science/Core collection, Embase, the Cochrane Library, and clinicaltrials.gov on 1 April 2022. We included two-arm and one-arm cohort studies that evaluated clinically relevant patient outcomes. Case reports were used to describe the type of CSF shunts used and the rationale behind its selection. The selection and extraction processes were independently performed by two authors. Results: This study included 20 cohort studies and 26 case reports. Only seven cohort studies compared two groups. Ventriculoperitoneal shunt was the most commonly used type of shunt (82.1%). The main indications for placing a shunt were persistently high opening pressure (57.1%) and persisting neurological symptoms or deterioration (54.3%). Cohort studies suggest that patients with shunt showed improvement in some outcomes such as neurological symptoms and hospital stay length. The most common shunt complications were post-operative fever (1–35.6%) and shunt obstruction (7–16%). Conclusion: CSF shunts may improve some clinically relevant outcomes in patients with CM, but the evidence is very uncertain.Revisión por pare

A Broadband Digital Spectrometer for the Deep Space Network

The Deep Space Network (DSN) enables NASA to communicate with its spacecraft in deep space. By virtue of its large antennas, the DSN can also be used as a powerful instrument for radio astronomy. Specifically, the Deep Space Station (DSS)-43, the 70 m antenna at the Canberra Deep Space Communications Complex (CDSCC), has a K-band radio astronomy system covering a 10 GHz bandwidth at 17–27 GHz. This spectral range covers a number of atomic and molecular lines, produced in a rich variety of interstellar gas conditions. Lines include hydrogen radio recombination lines (RRLs), cyclopropenylidene (C₃H₂), water masers (H₂O), and ammonia (NH₃). A new high-resolution spectrometer was deployed at CDSCC in 2019 November and connected to the K-band down converter. The spectrometer has a total bandwidth of 16 GHz. Such a large total bandwidth enables, for example, the simultaneous observations of a large number of RRLs, which can be combined together to significantly improve the sensitivity of these observations. The system has two firmware modes: (1) a 65k-pt fast Fourier transform to provide 32,768 spectral channels at 30.5 kHz and (2) a 16k-pt polyphase filter bank to provide 8192 spectral channels with a 122 kHz resolution. The observation process is designed to maximize autonomy, from the principle investigator's inputs to the output data in FITS file format. We present preliminary mapping observations of hydrogen RRLs in Orion KL mapping taken using the new spectrometer

Compressive strength and microstructure of alkali-activated mortars with high ceramic waste content

[EN] The present work investigated alkali-activated mortars with high ceramic waste contents. Tile ceramic waste (TCW) was used as both a recycled aggregate (TCWA) and a precursor (TCWP) to obtain a binding matrix by the alkali-activation process. Mortars with natural siliceous (quartz) and calcareous (limestone) aggregates, and with other ceramic waste materials (red clay brick RCB and ceramic sanitaryware CSW waste), were also prepared for comparison purposes. Given the lower density and higher water absorption values of the ceramic aggregates, compared to the natural ones, it was necessary to adapt the preparation process of the recycled mortars by presaturating the aggregate with water before mixing with the TCWP alkali-activated paste. Aggregate type considerably determined the mechanical behaviour of the samples cured at 65 °C for 3 days. The mortars prepared with the siliceous aggregate presented poor mechanical properties, even when cured at 65 °C. The behaviour of the limestone aggregate mortars depended heavily on the applied curing temperature and, although they presented the best mechanical properties of all those cured at room temperature, their compressive strength reached a maximum when cured at 65 °C, and then decreased. The mechanical properties of the mortars prepared with TCWA progressively increased with curing time (53 MPa at 65 °C for 28 days). An optimum 50 wt% proportion was observed for the limestone/TCWA mortars (¿43 MPa, 3 days at 65 °C), whereas the mechanical properties of that prepared with siliceous particles (10 MPa) progressively increased with the TCWA content, up to 100 wt% substitution (23 MPa). Limestone particles interacted with the binding matrix, and played an interesting beneficial role at the 20 °C curing temperature, with a slight reduction when cured long term (28 days) at 65 °C. The results demonstrated a potential added value for these ceramic waste materials.The authors would like to thank the Spanish Ministry of Science and Innovation and the Spanish Ministry of Economy and Competitiveness for supporting this study through Projects GEOCEDEM BIA 2011-26947 and BIA2015 70107-R, respectively. They also thank FEDER funding.Reig, L.; Sanz, M.; Borrachero Rosado, MV.; Monzó Balbuena, JM.; Soriano Martínez, L.; Paya Bernabeu, JJ. (2017). Compressive strength and microstructure of alkali-activated mortars with high ceramic waste content. Ceramics International. 43(16):16322-16334. https://doi.org/10.1016/j.ceramint.2017.07.072S1632216334431

Evaluation of the long-term compressive strength development of the sewage sludge ash/metakaolin-based geopolymer

[EN] This paper aimed to evaluate the long-term compressive strength development of the sewage sludge ash/metakaolin (SSA/MK)¿based geopolymer. SSA/MK¿based geopolymeric mortars and pastes were produced at 25ºC with different SSA contents (0 - 30 wt.%). Compressive strength tests were run within the 3-720 curing days range. A physicochemical characterisation (X-ray diffraction and scanning electron microscopy) was performed in geopolymeric pastes. All the geopolymeric mortars presented a compressive strength gain with curing time. The mortars with all the SSA evaluated contents (10, 20, 30 wt.%) developed a compressive strength over 40 MPa after 720 curing days at 25ºC. The maximum compressive strength of the mortars with SSA was approximately 61 MPa (10 wt.% of SSA), similarly to the reference mortar (100% MK-based geopolymer). The microstructure analyses showed that the SSA/MK¿based geopolymer presented a dense microstructure with N-A-S-H gel formation.This study was financed partly by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Su-perior -Brasil (CAPES) -(Finance Code 001 and CAPES/DGU n. 266/12), and the National Council of Scientific and Technological Development -Bra-sil (CNPq) -(n. 14/2013, process 478057/2013-0 and 309015/2015-4). The authors would like to thank Programa Institucional de Internacionalizacao - CAPES -PrInt. The authors acknowledge the Scanning Electron Microscopy Service of FEIS/UN-ESP, Servico Municipal Autonomo de Agua e Es-goto (SEMAE) from the Sao Jose do Rio Preto city -SP, Brazil and Diatom Mineracao Ltda. The authors would like to thank Programa Institucional de Internacionalizacao CAPES -PrInt.Istuque, D.; Soriano Martinez, L.; Borrachero Rosado, MV.; Paya Bernabeu, JJ.; Akasaki, JL.; Melges, JLP.; Tashima, MM. (2021). Evaluation of the long-term compressive strength development of the sewage sludge ash/metakaolin-based geopolymer. Materiales de Construcción. 71(343):1-10. https://doi.org/10.3989/mc.2021.13220S1107134

Asociación entre preocupación frente a la COVID-19, el apoyo social y el conocimiento sobre tuberculosis con el cumplimiento del tratamiento antituberculoso en Lima, Perú

Introducción. En el contexto de la pandemia por la COVID-19 es escasa la información de factores asociados al cumplimiento del tratamiento antituberculoso en las zonas de alta prevalencia de tuberculosis. Objetivo. Evaluar si existe asociación entre el apoyo social, la preocupación por el contagio de COVID-19 y el conocimiento de la tuberculosis, frente al incumplimiento del tratamiento antituberculoso. Materiales y métodos. Se trata de un estudio transversal de pacientes en tratamiento antituberculoso durante los meses de enero a marzo del 2022 en centros ubicados en áreas de alta prevalencia de tuberculosis en Lima. Se utilizó el cuestionario de Morisky Green-Levine para evaluar el cumplimiento del tratamiento como variable dependiente; las variables independientes se evaluaron usando el Medical Outcomes Study Social Support Survey para determinar el apoyo social percibido y la preocupación por la infección de COVID-19, y el test de Batalla para evaluar el conocimiento del paciente sobre su enfermedad. Se utilizó la regresión de Poisson con varianza robusta para determinar la asociación entre las variables. Resultados. De un total de 101 participantes (73,3 % hombres y edad media 35,1 ± 16 años), el 51,5 % no observaron el tratamiento antituberculoso. El nivel de preocupación medio o alto de contagiarse y desarrollar COVID-19 se asoció con una mayor prevalencia de incumplimiento del tratamiento (razón de prevalencia: 1,68; intervalo de confianza del 95 %: 1,09-2,57) (ajustada por las variables de confusión consideradas). Conclusiones. El incumplimiento del tratamiento antituberculoso es una condición frecuente entre los pacientes de una zona de alta prevalencia de tuberculosis en Lima especialmente entre aquellos con mayor preocupación al contagio por el virus de SARSCoV-2, causante de la COVID-19

Pozzolanic reactivity studies on a miomass-derived waste from sugar cane production: sugar cane straw ash (SCSA)

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Sustainable Chemistry & Engineering, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021%2Facssuschemeng.6b00770.”Biomass has gained in importance as an energy source in recent years. One of the crops that presents interesting opportunities with regard to biomass is sugar cane. In Brazil, sugar cane production is increasing for alcohol and sugar manufacture. Some by-products, such as sugar cane straw, also are obtained during harvesting. Due the calorific value of the sugar cane straw, its use as biomass is increasing. After the straw is burned to produce energy, an ash is obtained: sugar cane straw ash (SCSA). This waste needs an appropriate destination and, since the recent publication of successful studies using biomass derived-ashes as pozzolanic material, the present study aimed to assess the pozzolanic reactivity of sugar cane straw ash. The pozzolanic activity was assessed using a new and simple recently proposed method: evaluation of the electrical conductivity of calcium hydroxide (CH) and pozzolan suspensions, in which solid CH is initially present. These results were compared to those of two other well-established techniques: Fourier transformed infrared spectroscopy and thermogravimetric analysis. The evaluation by all three techniques is similar and shows that sugar cane straw ash is a good pozzolanic material: high lime fixation values for CH:SCSA mixes were determined by thermogravimetric analysis and unsaturation respect to CH in 3.5:6.5 CH:SCSA suspension was achieved at 60ºC. According to this behaviour, a bright future for SCSA as a replacement for Portland cement is expected.We thank CNPq (processo no. 401724/2013-1) and the "Ministerio de Education, Cultura y Deporte" of Spain ("Cooperacion Interuniversitaria" program with Brazil PHB-2011-0016-PC). Thanks are also due to the Electron Microscopy Service of the Universitat Politecnica de ValenciaMoraes, J.; Melges, JLP.; Akasaki, JL.; Tashima, MM.; Soriano Martínez, L.; Monzó Balbuena, JM.; Borrachero Rosado, MV.... (2016). Pozzolanic reactivity studies on a miomass-derived waste from sugar cane production: sugar cane straw ash (SCSA). ACS Sustainable Chemistry and Engineering. 4(8):4273-4279. https://doi.org/10.1021/acssuschemeng.6b00770S427342794

Surface modification of microparticles causes differential uptake responses in normal and tumoral human breast epithelial cells

Altres ajuts: FI-DGR 2013 de la Generalitat de CatalunyaThe use of micro- and nanodevices as multifunctional systems for biomedical applications has experienced an exponential growth during the past decades. Although a large number of studies have focused on the design and fabrication of new micro- and nanosystems capable of developing multiple functions, a deeper understanding of their interaction with cells is required. In the present study, we evaluated the effect of different microparticle surfaces on their interaction with normal and tumoral human breast epithelial cell lines. For this, AlexaFluor488 IgG functionalized polystyrene microparticles (3 μm) were coated with Polyethyleneimine (PEI) at two different molecular weights, 25 and 750 kDa. The effect of microparticle surface properties on cytotoxicity, cellular uptake and endocytic pathways were assessed for both normal and tumoral cell lines. Results showed a differential response between the two cell lines regarding uptake efficiency and mechanisms of endocytosis, highlighting the potential role of microparticle surface tunning for specific cell targeting