Síntesi de nanopartícules a gran escala amb major eficiència

El gran interès que han despertat els productes de nanopartícules, ha generat la necessitat de tenir a l'abast processos de síntesi que puguin ser aplicables en plantes pilot. La dificultat de controlar certs paràmetres del procés pot superar-se amb una síntesi contínua en microsistemes de flux, encara que els materials emprats habitualment tenen certs inconvenients. Un equip del Grup de Sensors i Biosensors, del Departament de Química, ha desenvolupat un innovador sistema per microflux utilitzant un material ceràmic que simplifica el muntage de la instal·lació i la monitorització del procés amb components electrònics.El gran interés que han despertado los productos de nanopartículas ha generado la necesidad de tener al alcance procesos de síntesis que puedan ser aplicables en plantas piloto. La dificultad de controlar ciertos parámetros del proceso puede superarse con una síntesis continua en microsistemas de flujo, aunque los materiales empleados habitualmente tienen ciertos inconvenientes. Un equipo del Grupo de Sensores y Biosensores, del Departamento de Química, ha desarrollado un innovador sistema con microflujo utilizando un material cerámico que simplifica el montaje de la instalación y la monitorización del proceso con componentes electrónicos

Microreactor with integrates temperature control for the synthesis of CdSe nanocrystals

The recent needs in the nanosciences field have promoted the interest towards the development of miniaturized and highly integrated devices able to improve and automate the current processes associated to the efficient nanomaterials production. Herein, a green tape based microfluidic system to perform high temperature controlled synthetic reactions of nanocrystals is presented. The device, which integrates both, the microfluidics and a thermally controlled platform, was applied to the automated and continuoussynthesis of CdSe quantum dots. Since temperature can be accurately regulated as required, sizecontrolled and reproducible quantum dots could be obtained by regulating this parameter and the molar ratio of precursors. The obtained nanocrystals were characterized by UV-Vis and fluorescencespectrophotometries. The band width of the emission peaks obtained indicates a narrow size distribution of the nanocrystals, which confirms the uniform temperature profile applied for each synthetic process, being the optimum temperature at 270° C (Full Width at Half Maximum = 40 nm). This approach allows a temperature controlled, easy, low cost and automated way to produce quantum dots in organic media, enhancing its application from laboratory-scale to pilot-line scale processes.This work has been supported by the Spanish Ministry of Science and Innovation (MICINN) through projects CTQ2009-12128 and the Consolider Ingenio 2010 project CSD2006 -12 and Catalonia 15 Government through SGR 2009 -0323

MEGARA-GTC stellar spectral library – II. MEGASTAR first release

MEGARA is an optical integral field and multi-object fibre-based spectrograph for the 10.4 m Gran Telescopio CANARIAS that offers medium-to-high spectral resolutions (FWHM) of R ≃ 6000, 12 000, 20 000. Commissioned at the telescope in 2017, it started operation as a common-user instrument in 2018. We are creating an instrument-oriented empirical spectral library from MEGARA-GTC stars observations, MEGASTAR, crucial for the correct interpretation of MEGARA data. This piece of work describes the content of the first release of MEGASTAR, formed by the spectra of 414 stars observed with R ≃ 20 000 in the spectral intervals 6420–6790 Å and 8370–8885 Å, and obtained with a continuum average signal-to-noise ratio around 260. We describe the release sample, the observations, the data reduction procedure and the MEGASTAR data base. Additionally, we include in Appendix A an atlas with the complete set of 838 spectra of this first release of the MEGASTAR catalogue.This work has been supported by MINECO-FEDER grants AYA2016-75808-R, AYA2016-79724-C4-3-P, RTI2018-096188-BI00, AYA2017-90589-REDT and has been partially funded by FRACTAL, INAOE, and CIEMAT

Temporal response to drought stress in several Prunus rootstocks and wild species

Prunus species are important crops in temperate regions. In these regions, drought periods are predicted to occur more frequently due to climate change. In this sense, to reduce the impact of climate warming, obtaining new tolerant/resistant cultivars and rootstocks is a mandatory goal in Prunus breeding. Therefore, the current study assembled three Prunus species including almond, (P. dulcis Mill D.A. Webb), apricot (P. armeniaca L.) and peach (P. persica L.) to model the temporal effects of drought. A hybrid peach × almond and a wild almond-relative species Prunus webbii were also included in the study. Physiological traits associated with photosynthetic activity, leaf water status, and chlorophyll content were assessed under three watering treatments. Results showed that effects of time, genotype, and treatment interact significantly in all traits. In addition, results confirmed that P. webbii have a greater tolerance to drought than commercial rootstocks. However, “Real Fino” apricot showed the fastest recovery after re-irrigation while being one of the most affected cultivars. In addition, from the better response to these watering treatments by the almond genotypes, two different trends were observed after re-irrigation treatment that clearly differentiate the response of the almond cultivar “Garrigue” from the rest of Prunus genotypes. A better characterization of the short-term drought response in Prunus, an accurate and more efficient evaluation of the genotype effect was obtained from the use of mixed models considering appropriate variance–covariance structures. Although the advantages of these approaches are rarely used in Prunus breeding, these methodologies should be undertaken in the future by breeders to increase efficiency in developing new breeding materials.info:eu-repo/semantics/publishedVersio

Microsystem-assisted synthesis of carbon dots with fluorescent and colorimetric properties for pH detection

The present paper describes the use of a microfluidic system to synthesize carbon dots (Cdots) and their use as optical pH sensors. The synthesis is based on the thermal decomposition of ascorbic acid in dimethyl sulfoxide. The proposed microsystem is composed of a fluidic and a thermal platform, which enable proper control of synthesis variables. Uniform and monodispersed 3.3 nm-sized Cdots have been synthesized, the optical characterization of which showed their down/upconversion luminescence and colorimetric properties. The obtained Cdots have been used for pH detection with down and upconverison fluorescent properties as excitation sources. The naked eye or a photographic digital camera has also been implemented as detection systems with the hue parameter showing a linear pH range from 3.5 to 10.2. On the other hand, experiments on the cytotoxicity and permeability of the Cdots on human embryonic kidney cells revealed their adsorption on cells without causing any impact on the cellular morphology.This work was supported by Projects SGR 2009-0323 from Catalonia Government and P10-FQM-5974 from the Junta de Andalucía (Spain). These projects were partially supported by European Regional Development Funds (ERDF). Our thanks to “Reincorporacion de Doctores UGR” programs and Greib startu

Ultrasensitive multiplex optical quantification of bacteria in large samples of biofluids

Efficient treatments in bacterial infections require the fast and accurate recognition of pathogens, with concentrations as low as one per milliliter in the case of septicemia. Detecting and quantifying bacteria in such low concentrations is challenging and typically demands cultures of large samples of blood (~1 milliliter) extending over 24-72 hours. This delay seriously compromises the health of patients. Here we demonstrate a fast microorganism optical detection system for the exhaustive identification and quantification of pathogens in volumes of biofluids with clinical relevance (~1 milliliter) in minutes. We drive each type of bacteria to accumulate antibody functionalized SERS-labelled silver nanoparticles. Particle aggregation on the bacteria membranes renders dense arrays of inter-particle gaps in which the Raman signal is exponentially amplified by several orders of magnitude relative to the dispersed particles. This enables a multiplex identification of the microorganisms through the molecule-specific spectral fingerprints

Autoregulatory loop of nuclear corepressor 1 expression controls invasion, tumor growth, and metastasis

Nuclear corepressor 1 (NCoR) associates with nuclear receptors and other transcription factors leading to transcriptional repression. We show here that NCoR depletion enhances cancer cell invasion and increases tumor growth and metastatic potential in nude mice. These changes are related to repressed transcription of genes associated with increased metastasis and poor prognosis in patients. Strikingly, transient NCoR silencing leads to heterochromatinization and stable silencing of the NCoR gene, suggesting that NCoR loss can be propagated, contributing to tumor progression even in the absence of NCoR gene mutations. Down-regulation of the thyroid hormone receptor β1 (TRβ) appears to be associated with cancer onset and progression. We found that expression of TRβ increases NCoR levels and that this induction is essential in mediating inhibition of tumor growth and metastasis by this receptor. Moreover, NCoR is down-regulated in human hepatocarcinomas and in the more aggressive breast cancer tumors, and its expression correlates positively with that of TRβ. These data provide a molecular basis for the anticancer actions of this corepressor and identify NCoR as a potential molecular target for development of novel cancer therapiesThis work was supported by Grants BFU2011-28058 and BFU2014-53610-P from Ministerio de Economía y Competitividad; Grant S2011/BMD-2328 from the Comunidad de Madrid; Grant RD12/0036/0030 from the Instituto de Salud Carlos III (to A.A.); Grants PI080971 and RD12 0036/0064 from the Instituto de Salud Carlos III (to J.P.); and Grant PI12/00386 from the Instituto de Salud Carlos III (to I.I.d.C.). O.A.M.-I. is supported by an Asociación Española Contra el Cáncer contrac

Five Patients with Disorders of Calcium Metabolism Presented with GCM2 Gene Variants

The GCM2 gene encodes a transcription factor predominantly expressed in parathyroid cells that is known to be critical for development, proliferation and maintenance of the parathyroid cells. A cohort of 127 Spanish patients with a disorder of calcium metabolism were screened for mutations by Next-Generation Sequencing (NGS). A targeted panel for disorders of calcium and phosphorus metabolism was designed to include 65 genes associated with these disorders. We observed two variants of uncertain significance (p.(Ser487Phe) and p.Asn315Asp), one likely pathogenic (p.Val382Met) and one benign variant (p.Ala393_Gln395dup) in the GCM2 gene in the heterozygous state in five families (two index cases had hypocalcemia and hypoparathyroidism, respectively, and three index cases had primary hyperparathyroidism). Our study shows the utility of NGS in unravelling the genetic origin of some disorders of the calcium and phosphorus metabolism, and confirms the GCM2 gene as an important element for the maintenance of calcium homeostasis. Importantly, a novel variant in the GCM2 gene (p.(Ser487Phe)) has been found in a patient with hypocalcemia.This study was supported by three grants from the Department of Health (2017111014, 2018111097 and 2019111052) and one grant from the Department of Education (IT1281-19) of the Basque Government. This work is generated within the Endocrine European Reference Network (Project ID number of Endo-ERN: 739527). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

The nature of the Cygnus extreme B supergiant 2MASS J20395358+4222505

2MASS J20395358+4222505 is an obscured early B supergiant near the massive OB star association Cygnus OB2. Despite its bright infrared magnitude (Ks = 5.82) it has remained largely ignored because of its dim optical magnitude (B = 16.63, V = 13.68). In a previous paper, we classified it as a highly reddened, potentially extremely luminous, early B-type supergiant. We obtained its spectrum in the U, B and R spectral bands during commissioning observations with the instrument MEGARA at the Gran Telescopio CANARIAS. It displays a particularly strong Hα emission for its spectral type, B1 Ia. The star seems to be in an intermediate phase between supergiant and hypergiant, a group that it will probably join in the near (astronomical) future. We observe a radial velocity difference between individual observations and determine the stellar parameters, obtaining Teff = 24 000 K and log gc = 2.88 ± 0.15. The rotational velocity found is large for a B supergiant, v sin i = 110 ± 25 kms−1⁠. The abundance pattern is consistent with solar, with a mild C underabundance (based on a single line). Assuming that J20395358+4222505 is at the distance of Cyg OB2, we derive the radius from infrared photometry, finding R = 41.2 ± 4.0 R⊙, log(L/L⊙) = 5.71 ± 0.04 and a spectroscopic mass of 46.5 ± 15.0 M⊙. The clumped mass-loss rate (clumping factor 10) is very high for the spectral type, M˙ = 2.4 × 10−6 M⊙ a−1. The high rotational velocity and mass-loss rate place the star at the hot side of the bi-stability jump. Together with the nearly solar CNO abundance pattern, they may also point to evolution in a binary system, J20395358+4222505 being the initial secondary.SS-D and AH acknowledge support from the Spanish Government Ministerio de Ciencia e Innovación through grants PGC-2018-091 3741-B-C22 and CEX2019-000920-S and from the Canarian Agency for Research, Innovation and Information Society (ACIISI), of the Canary Islands Government, and the European Regional Development Fund (ERDF), under grant with reference ProID2020010016. MG and FN acknowledge financial support through Spanish grant PID2019-105552RB-C41 (MINECO/MCIU/AEI/FEDER) and from the Spanish State Research Agency (AEI) through the Unidad de Excelencia ‘María de Maeztu’-Centro de Astrobiología (CSIC-INTA) project No. MDM-2017-0737. SRB acknowledges support by the Spanish Government under grants AYA2015-68012-C2-2-P and PGC2018-093741-B-C21/C22 (MICIU/AEI/FEDER, UE). SRA acknowledges funding support from the FONDECYT Iniciación project 11171025 and the FONDECYT Regular project 1201490. JIP acknowledges finantial support from projects Estallidos6 AYA2016-79724-C4 (Spanish Ministerio de Economia y Competitividad), Estallidos7 PID2019-107408GB-C44 (Spanish Ministerio de Ciencia e Innovacion), grant P18-FR-2664 (Junta de Andalucía), and grant SEV-2017-0709 ‘Centro de Excelencia Severo Ochoa Program’ (Spanish Science Ministry). AGP, SP, AG-M, JG and NC acknowledge support from the Spanish MCI through project RTI2018-096188-B-I00