Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
Repositorio Institucional del CIEMAT (Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas)Not a member yet
1694 research outputs found
Sort by
The gray boundaries of aberrant shortening of the cellular timekeepers??? edges
Full text linkTelomeres are supramolecular structures that allow the DNA strand to fold back on itself and protect the linear chromosome end from being sensed as a double-strand DNA break. Telomeric conservation relies on mechanisms that replace terminal DNA sequences, and ensuring structural integrity. Telomere biology disorders (TBDs) are a heterogeneous group of low-prevalence pathologies defined by germline mutations in genes involved in telomere maintenance mechanisms (TMMs). TBDs manifest across a broad clinical spectrum, often with substantial phenotypic and genetic overlap among clinical entities. In this issue of EMBO Molecular Medicine, Tummala and collaborators present clinical and biological data from DC/DCL patients, that enhances the understanding of the natural history of these diseases. In addition, the description of novel TBD-associated genetic variants in POT1 and ZCCHC8 and of the new POLA1 gene advances the understanding of the functional network of genes involved in TBD and highlights new pathogenic mechanisms
Measurement of Ge-73(n,??) cross sections and implications for stellar nucleosynthesis
Full text linkGe-73(n,??) cross sections were measured at the neutron time-of-flight facility n_TOF at CERN up to neutron energies of 300 keV, providing for the first time experimental data above 8 keV. Results indicate that the stellar cross section at kT = 30 keV is 1.5 to 1.7 times higher than most theoretical predictions. The new cross sections result in a substantial decrease of Ge-73 produced in stars, which would explain the low isotopic abundance of Ge-73 in the solar system
Phenotypic characterization of BRCA1 and BRCA2 tumors based in a tissue microarray study with 37 immunohistochemical markers
Full text linkFamilial breast cancers that are associated with BRCA1 or BRCA2 germline mutations differ in both their morphological and immunohistochemical characteristics.
To further characterize the molecular difference between genotypes, the authors evaluated the expression of 37 immunohistochemical markers in a tissue microarray (TMA) containing cores from 20 BRCA1, 14 BRCA2, and 59 sporadic age-matched breast carcinomas. Markers analyzed included, amog others, common markers in breast cancer, such as hormone receptors, p53 and HER2, along with 15 molecules involved in cell cycle regulation, such as cyclins, cyclin dependent kinases (CDK) and CDK inhibitors (CDKI), apoptosis markers, such as BCL2 and active caspase 3, and two basal/myoepithelial markers (CK 5/6 and P-cadherin). In addition, we analyzed the amplification of CCND1, CCNE, HER2 and MYC by FISH.
Unsupervised cluster data analysis of both hereditary and sporadic cases using the complete set of immunohistochemical markers demonstrated that most BRCA1-associated carcinomas grouped in a branch of ER-, HER2-negative tumors that expressed basal cell markers and/or p53 and had higher expression of activated caspase 3. The cell cycle proteins associated with these tumors were E2F6, cyclins A, B1 and E, SKP2 and Topo II. In contrast, most BRCA2- associated carcinomas grouped in a branch composed by ER/PR/BCL2-positive tumors with a higher expression of the cell cycle proteins cyclin D1, cyclin D3, p27, p16, p21, CDK4, CDK2 and CDK1.
In conclusion, our study in hereditary breast cancer tumors analyzing 37 immunohistochemical markers, define the molecular differences between BRCA1 and BRCA2 tumors with respect to hormonal receptors, cell cycle, apoptosis and basal cell markers
Combination of Models to Generate the First PAR Maps for Spain
Full text linkThis work addresses the development of a PAR model in the entire territory of mainland Spain. Thus, a specific model is developed for each location of the study field. The new PAR model consists of a combination of the estimates of two previous models that had unequal performances in different climates. In fact, one of them showed better results with Mediterranean climate, whereas the other obtained better results under oceanic climate. Interestingly, the new PAR model showed similar performance when validated at seven stations in mainland Spain with Mediterranean or oceanic climate. Furthermore, all validation slopes ranged from 0.99 to 1.00; the intercepts were less than 3.70 umol m-2 s-1; the R2 were greater than 0.988, while MBE was closer to zero percent than -0.39%; and RMSE were less than 6.21%. The estimates of the PAR model introduced in this work were then used to develop PAR maps over mainland Spain that represent daily PAR averages of each month and a full year at all locations in the study field
Multifunctional HIL Testbench for Hybrid Energy Storage Systems Analysis
No full textThis paper presents a multifunctional Hardware-inthe- Loop (HIL) testing facility developed by CIEMAT???s Unidad de Accionamientos El??ctricos for analyzing and validating hybrid energy storage systems (HESS). The facility integrates lithium-ion battery systems (Li-BESS), supercapacitors (SCs), and flywheel (FW) storage, alongside a real-time emulation platform. Two distinct case studies are discussed: the HYBRIDHYDRO project, which couples hydroelectric generation with Li-BESS and SCs to mitigate mechanical wear and provide frequency regulation, and the POSEIDON project, examining the hybridization of SCs or FWs with existing Li-BESS in maritime vessels to reduce battery aging. Experimental tests demonstrate that appropriately tuned hybrid configurations effectively reduce mechanical stress in hydroelectric systems and battery aging in maritime applications, highlighting significant technical benefits
Comprehensive Optoelectronic Study of Copper Nitride:Dielectric Function and Bandgap Energies.
No full textCopper nitride (Cu3N) is gaining attention as an eco-friendly thin-film semiconductor in a
myriad of applications, including storage devices, microelectronic components, photodetectors,
and photovoltaic cells. This work presents a detailed optoelectronic study of Cu3N
thin films grown by reactive RF-magnetron sputtering under pure N2. An overview of the
state-of-the-art literature on this material and its potential applications is also provided. The
studied films consist of Cu3N polycrystals with a cubic anti-ReO3 type structure exhibiting
a preferential (100) orientation. Their optical properties across the UV-Vis-NIR spectral
range were investigated using a combination of multi-angle spectroscopic ellipsometry,
broadband transmission, and reflection measurements. Our model employs a stratified
geometrical approach, primarily to capture the depth-dependent compositional variations
of the Cu3N film while also accounting for surface roughness and the underlying glass
substrate. The complex dielectric function of the film material is precisely determined
through an advanced dispersion model that combines multiple oscillators. By integrating
the Tauc???Lorentz, Gaussian, and Drude models, this approach captures the distinct
electronic transitions of this polycrystal. This customized optical model allowed us to
accurate extract both the indirect (1.83???1.85 eV) and direct (2.38???2.39 eV) bandgaps. Our
multifaceted characterization provides one of the most extensive studies of Cu3N thin films
to date, paving the way for optimized device applications and broader utilization of this
promising binary semiconductor, and showing its particular potential for photovoltaic
given its adequate bandgap energies for solar applications
Influence of synoptic meteorology on airborne allergenic pollen and spores in an urban environment in Northeastern Iberian Peninsula
Full text linkThe influence of the most frequent patterns of synoptic circulation on the dynamics of airborne pollen/spores recorded at the Barcelona Aerobiological Station (BCN) was analysed. Six pollen types (Platanus, Cupressaceae, Olea, Poaceae, Urticaceae and Amaranthaceae), and one fungal spore (Alternaria) were selected for their high allergenic effect in sensitive people. Six synoptic meteorological patterns were identified through cluster analysis of sea level pressure fields as the main responsible of the weather conditions in the Iberian Peninsula. The local meteorological conditions in Barcelona associated with each one of the synoptic types were also stablished. Different statistical methods were applied to analyse possible relationships between concentrations and timing of the recorded aerobiological particles and specific synoptic types. The study, focused in the 19-year period 2001???2019, shows that one of the scenarios, frequent in winter and linked to high stability and air-mass blockage, registered the highest mean and median values for Platanus and Cupressaceae, but it was not very relevant for the other taxa. It was also this scenario that turned out to be the most influent on the pollination timing showing a significant influence on the start occurrence of Urticaceae flowering and on the peak date of Platanus. On the other hand, the most frequent synoptic type in the period, relevant in spring and summer, was linked to sporadic episodes of levels considered to be of high risk of allergy to Platanus, Poaceae, and Urticaceae pollen, and Alternaria fungal spore. This synoptic pattern, characterized by the presence of the Azores anticyclone and the Atlantic low located in the north of the United Kingdom, was associated with high temperatures, low relative humidity and moderate winds from the NW in Barcelona. The identification of an interaction between synoptic meteorology and pollen/spore dynamics will allow better abatement measures, reducing adverse health effects on sensitive population
An EARLINET early warning system for atmospheric aerosol aviation hazards
Full text linkA stand-alone lidar-based method for detecting
airborne hazards for aviation in near real time (NRT) is
presented. A polarization lidar allows for the identifica tion of irregular-shaped particles such as volcanic dust and
desert dust. The Single Calculus Chain (SCC) of the Eu ropean Aerosol Research Lidar Network (EARLINET) de livers high-resolution preprocessed data: the calibrated to tal attenuated backscatter and the calibrated volume linear
depolarization ratio time series. From these calibrated lidar
signals, the particle backscatter coefficient and the particle
depolarization ratio can be derived in temporally high reso lution and thus provide the basis of the NRT early warning
system (EWS). In particular, an iterative method for the re trieval of the particle backscatter is implemented. This im proved capability was designed as a pilot that will produce
alerts for imminent threats for aviation. The method is ap plied to data during two diverse aerosol scenarios: first, a
record breaking desert dust intrusion in March 2018 over Fi nokalia, Greece, and, second, an intrusion of volcanic parti cles originating from Mount Etna, Italy, in June 2019 over
Antikythera, Greece. Additionally, a devoted observational
period including several EARLINET lidar systems demon strates the network???s preparedness to offer insight into natural hazards that affect the aviation sector
Neutron Capture on the s-Process Branching Point Tm-171 via Time-of-Flight and Activation
Full text linkThe neutron capture cross sections of several unstable nuclides acting as branching points in the s process are crucial for stellar nucleosynthesis studies. The unstable Tm-171 (t1/2 = 1.92 yr) is part of the branching around mass A ??? 170 but its neutron capture cross section as a function of the neutron energy is not known to date. In this work, following the production for the first time of more than 5 mg of Tm-171 at the high-flux reactor Institut Laue-Langevin in France, a sample was produced at the Paul Scherrer Institute in Switzerland. Two complementary experiments were carried out at the neutron time-of-flight facility (n TOF) at CERN in Switzerland and at the SARAF liquid lithium target facility at Soreq Nuclear Research Center in Israel by time of flight and activation, respectively. The result of the time-of-flight experiment consists of the first ever set of resonance parameters and the corresponding average resonance parameters, allowing us to make an estimation of the Maxwellian-averaged cross sections (MACS) by extrapolation. The activation measurement provides a direct and more precise measurement of the MACS at 30 keV: 384(40) mb, with which the estimation from the n TOF data agree at the limit of 1 standard deviation. This value is 2.6 times lower than the JEFF-3.3 and ENDF/B-VIII evaluations, 25% lower than that of the Bao et al. compilation, and 1.6 times larger than the value recommended in the KADoNiS (v1) database, based on the only previous experiment. Our result affects the nucleosynthesis at the A???170 branching, namely, the Yb-171 abundance increases in the material lost by asymptotic giant branch stars, providing a better match to the available pre-solar SiC grain measurements compared to the calculations based on the current JEFF-3.3 model-based evaluation