DC-Voltage-Ratio Control Strategy for Multilevel Cascaded Converters Fed With a Single DC Source

Recently, a multilevel cascaded converter fed with a single DC source has been presented. An analysis of the steady-state working limits of this type of converter is presented in this paper. Limits of the maximum output voltage and the minimum and maximum loading conditions for stable operation of the converter are addressed. In this paper, a way to achieve any DC voltage ratio (inside the stable operation area of the converter) between the H-bridges of the single-DC-source cascaded H-bridge converter is presented. The proposed DC-voltage-ratio control is based on a time-domain modulation strategy that avoids the use of inappropriate states to achieve the DC-voltage-ratio control. The proposed technique is a feedforward-modulation technique which takes into account the actual DC voltage of each H-bridge of the converter, leading to output waveforms with low distortion. In this way, the dc voltage of the floating H-bridge can be controlled while the output voltage has low distortion independently of the desired DC voltage ratio. Experimental results from a two-cell cascaded converter are presented in order to validate the proposed DC-voltage-ratio control strategy and the introduced concepts.Ministerio de Ciencia y Tecnología TEC2006-03863Junta de Andalucía EXC/2005/TIC-117

La libertad que existe. Bioética internacional durante el estado de emergencia por covid–19

A través de la revisión de 40 de las 51 guías bioéticas de 28 países publicadas por la Organización Mundial de la Salud en sus contenidos sobre covid–19 en el primer semestre de 2020, se hace una reflexión crítica del accionar ético de tres gobiernos durante el estado de emergencia sanitario: el alemán, el inglés y el jalisciense, para después realizar una valoración de los aportes normativos de estas guías y plantear líneas de reflexión para la deliberación médica, política, jurídica y bioética, útiles en posibles estados de emergencia futuros.ITESO, A.C

Dark matter from primordial black holes would hold charge

We explore the possibility that primordial black holes (PBHs), formed early in the history of the Universe, contain electric charge down to the present day. We find that PBHs should hold a non-zero charge at their formation, sourced by both Poisson fluctuations and collisions of charged particles in the early universe. Although initial charges could be of either sign and are thought to be subject to fast discharge processes, we show that dipolar magnetic fields from rotating black holes can deviate them, avoiding their accretion or emission to infinity, regardless of the PBH mass. Moreover, we find that charged, maximally rotating PBHs produce magnetic fields able to cancel the Schwinger effect for all masses, and the Hawking emission for PBHs with M>1\,\mbox{kg}. These mechanisms could allow PBHs to maintain their charge for extended periods. At late times, we conclude that the plasma within virialised dark matter haloes can endow PBHs with a net average negative charge. We report resulting charges Q/M \sim -10^{-32}\,C/\mbox{kg} and Q/M \sim -10^{-22}\,C/\mbox{kg} for two current windows where PBHs can make up all of the dark matter; being respectively M\sim 10^{20}\,\mbox{kg} and M\sim 10^{30}\,\mbox{kg}. The charge of PBHs in haloes lies below the Schwinger limit for discharge, which would effectively make PBH dark matter slightly non-neutral to the present day. Altogether, the initial PBH charge, possible shielding against discharge, and late time negative charge accretion, show that PBHs of all masses could hold a net charge, with values about two to ten orders of magnitude lower than the maximal bound imposed by subextremal Reissner-Nordstr\"om (RN) PBHs, and even the extremal charge for Planck mass PBHs. The latter are of particular interest, as they could constitute charged stable relics, composing the entirety of dark matter in the Universe.Comment: 24 pages, 6 figures, minor changes, matches the version submitted to the journa

Monitoring spin-crossover phenomena via Re(I) luminescence in hybrid Fe(II) silica coated nanoparticles

Financial support from Projects CTQ2014-56312-P and PGC2018-102052-B-C21 financed by MCIN/AEI/10.13039/501100011033/FEDER "Una manera de hacer Europa", the Junta de Andalucia (FQM-195), Feder project A-FQM-172UGR18 and the University of Granada is gratefully acknowledged. I.-F. Diaz-Ortega and J.-R Jimenez are also thankful to the Junta de Andalucia for Postdoctoral research fellowships.Bare (1) and silica coated (1@SiO2) spin crossover (SCO) nanoparticles based on the polymer {[Fe (NH2Trz)3](BF4)2}n have been prepared following a water-in-oil synthetic procedure. For 1, the critical temperatures of the spin transition are TC↓ = 214.6 K and TC↑ = 220.9 K. For 1@SiO2, the abruptness of the transition is enhanced and the critical temperatures are centred at room temperature (TC↓ = 292.1 K and TC↑ = 296.3 K). An inert Re(I) complex of formula [Re(phen)(CO)3(PETES)](PF6) (phen = 1, 10-phenanthroline; PETES = 2(4-pyridylethyl)triethoxysilane) (Re) was also synthesized yielding intense green emission centred at λem = 560 nm. The grafting of this complex on the silica shell of 1@SiO2 led to a bifunctional SCO-luminescence composite (1@SiO2/Re) whose luminescence properties were tuned by the spin state switching. Temperature-variable photophysical studies showed that luminescence and spin transition were synchronized through a radiative (trivial) energy transfer mechanism between the Re(I) and the Fe(II)-LS (LS, Low Spin) centres.FEDER "Una manera de hacer Europa" CTQ2014-56312-P PGC2018-102052-B-C21Junta de Andalucia FQM-195European Commission A-FQM-172UGR18University of GranadaJunta de Andaluci

Protein Tyrosine Nitration during Development and Abiotic Stress Response in Plants

In recent years, the study of nitric oxide (NO) in plant systems has attracted the attention of many researchers. A growing number of investigations have shown the significance of NO as a signal molecule or as a molecule involved in the response against (a)biotic processes. NO can be responsible of the post-translational modifications (NO-PTM) of target proteins by mechanisms such as the nitration of tyrosine residues. The study of protein tyrosine nitration during development and under biotic and adverse environmental conditions has increased in the last decade; nevertheless, there is also an endogenous nitration which seems to have regulatory functions. Moreover, the advance in proteome techniques has enabled the identification of new nitrated proteins, showing the high variability among plant organs, development stage and species. Finally, it may be important to discern between a widespread protein nitration because of greater RNS content, and the specific nitration of key targets which could affect cell-signaling processes. In view of the above point, we present a mini-review that offers an update about the endogenous protein tyrosine nitration, during plant development and under several abiotic stress conditions.This study was supported by an ERDF grant co-financed by the Ministry of Economy and Competitiveness (project BIO2015-66390-P) and Junta de Andalucía (groups BIO286 and BIO192). Research in FJC laboratory is supported by an ERDF grant co-financed by the Ministry of Economy and Competitiveness (AGL2015-65104-P).Peer reviewedPeer Reviewe

Impact of an enhanced screening program on the detection of non-AIDS neoplasias in patients with human immunodeficiency virus infection

Background The incidence of non-AIDS defining cancer (NADC) is higher in people living with HIV (PLWH) than in the general population, and it is already one of the leading causes of death in the HIV-infected population. It is estimated that the situation will be aggravated by the progressive aging of PLWH. Early diagnosis through intensive cancer screening may improve the ability for therapeutic interventions and could be critical in reducing mortality, but it might also increase expenditure and harms associated with adverse events. The aim of this study is to evaluate an enhanced screening program for early diagnosis of cancer in PLWH compared to standard practice. The specific objectives are (1) to compare the frequency of cancer diagnosed at an early stage, (2) to analyze safety of the enhanced program: adverse events and unnecessary interventions, (3) to analyze the cost-utility of the program, and (4) to estimate the overall and site-specific incidence of NADC in PLWH. Methods We will conduct a multicenter, non-blinded, randomized, controlled trial, comparing two parallel arms: conventional vs enhanced screening. Data will be recorded in an electronic data collection notebook. Conventional intervention group will follow the standard of care screening in the participating centers, according to the European AIDS Clinical Society recommendations, and the enhanced intervention group will follow an expanded screening aimed to early detection of lung, liver, anal, cervical, breast, prostate, colorectal, and skin cancer. The trial will be conducted within the framework of the Spanish AIDS Research Network Cohort (CoRIS). Discussion The trial will evaluate the efficacy, safety, and efficiency of an enhanced screening program for the early diagnosis of cancer in HIV patients compared to standard of care practice. The information provided will be relevant since there are currently no studies on expanded cancer screening strategies in patients with HIV, and available data estimating cost effectiveness or cost-utility of such as programs are scarce. An enhanced program for NADC screening in patients with HIV could lead to early diagnosis and improve the prognosis of these patients, with an acceptable rate of unnecessary interventions, but it is critical to demonstrate that the benefits clearly outweigh the harms, before the strategy could be implemented

N,N′-Bis(4-amino­benz­yl)oxalamide

In the title compound, C16H18N4O2, the two carbonyl groups are in an anti­periplanar conformation with an O=C—C=O torsion angle of 173.86 (17)°. In the crystal, a pair of inter­molecular N—H⋯O hydrogen bonds, forming an R 2 2(10) ring motif, connect the mol­ecules into an inversion dimer. The dimers are further linked by N—H⋯N and C—H⋯π inter­actions, forming a zigzag chain along the b axis

Effects of dietary vegetable oils on mammary lipid-related genes in holstein dairy cows

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Effects of dietary polyunsaturated fatty acid sources on expression of lipid-related genes in bovine milk somatic cells

© 2020, The Author(s). The objective of this study was to compare the effect of contrasting sources of dietary n-6 and n-3 PUFA on expression of genes related to lipid metabolism in dairy cows. During 63days, fifteen lactating cows were assigned to a control or basal diet containing no added lipid (n = 5 cows); and treatment diets supplemented with SO (n = 5 cows; unrefined soybean oil; 2.9% of DM) or FO (n = 5 cows; fish oil manufactured from salmon oil; 2.9% of DM). Plasma for fatty acid (FA) analysis and milk somatic cells (MSC) were obtained from all cows at the beginning of the study (day 0) and on days 21, 42 and 63. Plasma was used to determine FA transport dynamics. Compared with control and FO, plasma from SO had increased contents of C18:1 cis-9, C18:1 trans-11, C18:2 cis-9, trans-11 and total monounsaturated FA. On the other hand, compared with control and SO, FO increased plasma contents of C20:3 n-3, C20:3 n-6, C20:4 n-6, C20:5 n-3, C22:6 n-3 and total polyunsaturated FA. Moreover, plasma C18:3 n-3 and C20:5 n-3 increased over time for all diets. Compared with control, SO downregulated ACACA, INSIG1, and DGAT1, whereas FO downregulated ACACA, PPARGC1, LPIN1 and FABP3 on day 63, in MSC. At different time-points, SO and FO downregulated genes related to synthesis and intracellular transport of FA, synthesis of triglycerides, and transcription factors