FCE - Artículos de Revista

Examinar

Mostrando 1 - 20 de 1578

Development of molecularly imprinted polymers for the detection of human chorionic gonadotropin
(Nature Research, 0025) Zubrytė, Radvilė; Mavliutova, Liliia; García, Yadiris; Sullivan, Mark V.; Turner, Nicholas W.; Patitucci, Francesco; Polania, Laura C.; Jiménez, Verónica A; Porter, Robert; Mattsson, Alice; Sellergren, Börje
Diagnostic pregnancy tests are the most widely used immunoassays for home-based use. These tests employ the well-established lateral flow assay (LFA) technique, reminiscent of affinity chromatography relying on the dual action of two orthogonal anti-hCG antibodies. Immunoassays suffer from several drawbacks, including challenges in antibody manufacturing, suboptimal accuracy, and sensitivity to adverse storing conditions. Additionally, LFAs are typically designed for single use, as the LFA technique is non-reusable. An alternative to overcome these drawbacks is to leverage molecularly imprinted polymer (MIP) technology to generate polymer-based hCG-receptors and, subsequently, non-bioreceptor-based tests. Here, we report the development of MIP nanogels for hCG detection, exploiting epitopes and magnetic templates for high-yielding dispersed phase imprinting. The resulting nanogels were designed for orthogonal targeting of two immunogenic epitopes (SV and PQ) and were thoroughly characterized with respect to physical properties, binding affinity, specificity, and sensitivity. Molecular dynamics simulations indicated a pronounced conformational overlap between the templates and the epitopes in the native protein, supporting their suitability for templating cavities for hCG recognition. Quartz crystal microbalance (QCM)-based binding tests and kinetic interaction analysis by surface plasmon resonance (SPR) revealed nanomolar dissociation constants for the MIP nanogels and their corresponding template peptides and low uptake of lutenizing hormone (LH), structurally resembling to hCG. Receptor reusability was demonstrated in the multicycle SPR sensing mode using a low pH regeneration buffer. The results suggest the feasibility of using imprinted nanogels as a class of cost-effective, stable alternatives to natural antibodies for hCG detection. We foresee applications of these binders with respect to reusable pregnancy tests and other hCG-related disease diagnostics. © The Author(s) 2025.
Search for dark matter produced in association with a single top quark in √s=13 TeV pp collisions with the ATLAS detector
(Springer Science and Business Media Deutschland GmbH, 2021-10) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A. Abed; Abeling, K.; Abhayasinghe, D.K.; Abidi, S.H.; AbouZeid, O.S.; Abraham, N.L.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B.S.; Achkar, B.; Adam, L.; Bourdarios, C. Adam; Adamczyk, L.; Adamek, L.; Adelman, J.; Adiguzel, A.; Adorni, S.; Adye, T.; Affolder, A.A.; Afik, Y.; Agapopoulou, C.; Agaras, M.N.; Aggarwal, A.; Agheorghiesei, C.; Aguilar-Saavedra, J.A.; Ahmad, A.; Ahmadov, F.; Ahmed, W.S.; Ai, X.; Aielli, G.; Akatsuka, S.; Akbiyik, M.; Åkesson, T.P.A.; Akilli, E.; Akimov, A.V.; Khoury, K. Al; Alberghi, G.L.; Albert, J.; Verzini, M. J. Alconada; Alderweireldt, S.; Aleksa, M.; Aleksandrov, I.N.; Alexa, C.; Alexopoulos, T.; Alfonsi, A.; Alfonsi, F.; Alhroob, M.; Ali, B.; Ali, S.; Aliev, M.; Alimonti, G.; Allaire, C.; Allbrooke, B.M.M.; Allen, B.W.; Allport, P.P.; Aloisio, A.
This paper presents a search for dark matter in the context of a two-Higgs-doublet model together with an additional pseudoscalar mediator, a, which decays into the dark-matter particles. Processes where the pseudoscalar mediator is produced in association with a single top quark in the 2HDM+a model are explored for the first time at the LHC. Several final states which include either one or two charged leptons (electrons or muons) and a significant amount of missing transverse momentum are considered. The analysis is based on proton–proton collision data collected with the ATLAS experiment at s=13 TeV during LHC Run 2 (2015–2018), corresponding to an integrated luminosity of 139 fb - 1. No significant excess above the Standard Model predictions is found. The results are expressed as 95% confidence-level limits on the parameters of the signal models considered. © 2021, The Author(s).
Search for dark matter in events with missing transverse momentum and a Higgs boson decaying into two photons in pp collisions at √s = 13 TeV with the ATLAS detector
(Springer Science and Business Media Deutschland GmbH, 2021-10) Aad, G.; Abbott, B.; Abbott, D.C.; Abed Abud, A.; Abeling, K.; Abhayasinghe, D.K.; Abidi, S.H.; AbouZeid, O.S.; Abraham, N.L.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B.S.; Achkar, B.; Adam, L.; Adam Bourdarios, C.; Adamczyk, L.; Adamek, L.; Adelman, J.; Adiguzel, A.; Adorni, S.; Adye, T.; Affolder, A.A.; Afik, Y.; Agapopoulou, C.; Agaras, M.N.; Aggarwal, A.; Agheorghiesei, C.; Aguilar-Saavedra, J.A.; Ahmad, A.; Ahmadov, F.; Ahmed, W.S.; Ai, X.; Aielli, G.; Akatsuka, S.; Akbiyik, M.; Åkesson, T.P.A.; Akilli, E.; Akimov, A.V.; Al Khoury, K.; Alberghi, G.L.; Albert, J.; Alconada Verzini, M.J.; Alderweireldt, S.; Aleksa, M.; Aleksandrov, I.N.; Alexa, C.; Alexopoulos, T.; Alfonsi, A.; Alfonsi, F.; Alhroob, M.; Ali, B.; Ali, S.; Aliev, M.; Alimonti, G.; Allaire, C.; Allbrooke, B.M.M.; Allport, P.P.; Aloisio, A.; Alonso, F.
A search for dark-matter particles in events with large missing transverse momentum and a Higgs boson candidate decaying into two photons is reported. The search uses 139 fb−1 of proton-proton collision data collected at s = 13 TeV with the ATLAS detector at the CERN LHC between 2015 and 2018. No significant excess of events over the Standard Model predictions is observed. The results are interpreted by extracting limits on three simplified models that include either vector or pseudoscalar mediators and predict a final state with a pair of dark-matter candidates and a Higgs boson decaying into two photons. [Figure not available: see fulltext.] © 2021, The Author(s).
Designing an Optimal Kilonova Search Using DECam for Gravitational-wave Events
(Institute of Physics, 0024) Bom C.R.; Annis J; Garcia A.; Palmese A.; Sherman N.; Soares-Santos M.; Santana-Silva L; Morgan R.; Bechtol K; Davis T.; Diehl H.T.; Allam S.S.
We address the problem of optimally identifying all kilonovae detected via gravitational-wave emission in the upcoming LIGO/Virgo/KAGRA observing run, O4, which is expected to be sensitive to a factor of ∼7 more binary neutron star (BNS) alerts than previously. Electromagnetic follow-up of all but the brightest of these new events will require >1 m telescopes, for which limited time is available. We present an optimized observing strategy for the DECam during O4. We base our study on simulations of gravitational-wave events expected for O4 and wide-prior kilonova simulations. We derive the detectabilities of events for realistic observing conditions. We optimize our strategy for confirming a kilonova while minimizing telescope time. For a wide range of kilonova parameters, corresponding to a fainter kilonova compared to GW170817/AT 2017gfo, we find that, with this optimal strategy, the discovery probability for electromagnetic counterparts with the DECam is ∼80% at the nominal BNS gravitational-wave detection limit for O4 (190 Mpc), which corresponds to an ∼30% improvement compared to the strategy adopted during the previous observing run. For more distant events (∼330 Mpc), we reach an ∼60% probability of detection, a factor of ∼2 increase. For a brighter kilonova model dominated by the blue component that reproduces the observations of GW170817/AT 2017gfo, we find that we can reach ∼90% probability of detection out to 330 Mpc, representing an increase of ∼20%, while also reducing the total telescope time required to follow up events by ∼20%. © 2024. The Author(s). Published by the American Astronomical Society
Multiplicity of Galactic Cepheids from long-baseline interferometry V. High-accuracy orbital parallax and mass of SU Cygni
(Astronomy and Astrophysics, Volume 6931 January 2025 Article number A111, 2025) Gallenne A.; Evans N.R.; Kervella P.; Monnier J.D.; Proffitt C.R.; Schaefer G.H.; Winston E.M.; Kuraszkiewicz J.; Mérand A.; Pietrzynski G.; Gieren W. k; Pilecki B.; Kraus S. l;; Le Bouquin J.-B.; Anugu N.; Brummelaar T.; Chhabra S.; Codron I.; Davies C.L.; Ennis J.; Gardner T.; Gutierrez M.; Ibrahim N.; Lanthermann C.; Mortimer D.; Setterholm B.R.
Aims. We aim to accurately measure the dynamical mass and distance of Cepheids by combining radial velocity measurements with interferometric observations. Cepheid mass measurements are particularly necessary for solving the Cepheid mass discrepancy, while independent distance determinations provide a crucial test of the period–luminosity relation and Gaia parallaxes. Methods. We used the multi-telescope interferometric combiner, the Michigan InfraRed Combiner (MIRC) of the Center for High Angular Resolution Astronomy (CHARA) Array, to detect and measure the astrometric positions of the high-contrast companion orbiting the Galactic Cepheid SU Cygni. We also present new radial velocity measurements from ultraviolet spectra taken with the Hubble Space Telescope. The combination of interferometric astrometry with optical and ultraviolet spectroscopy provided the full orbital elements of the system, in addition to component masses and the distance to the Cepheid system. Results. We measured the mass of the Cepheid, MA = 4.859 ± 0.058 M , and its two companions, MBa = 3.595 ± 0.033 M and MBb = 1.546 ± 0.009 M . This is the most accurate existing measurement of the mass of a Galactic Cepheid (1.2%). Comparing with stellar evolution models, we show that the mass predicted by the tracks is higher than the measured mass of the Cepheid, which is similar to the conclusions of our previous work. We also measured the distance to the system to be 926.3 ± 5.0 pc, obtaining an unprecedented parallax precision of 6 µas (0.5%), which is the most precise and accurate distance for a Cepheid. This precision is similar to what is expected by Gaia for its last data release (DR5 in ∼2030) for single stars fainter than G = 13, but is not guaranteed for stars as bright as SU Cyg. Conclusions. We demonstrate that evolutionary models remain incapable of accurately reproducing the measured mass of Cepheids, often predicting higher masses for the expected metallicity, even when factors such as rotation or convective core overshooting are taken into account. Our precise distance measurement allowed us to compare predictions from some period–luminosity relations. We find a disagreement of 0.2–0.5 mag with relations calibrated from photometry, while relations calibrated from a direct distance measurement are in better agreement. © The Authors 2025
Searching for HI around MHONGOOSE galaxies via spectral stacking
(Astronomy and Astrophysics, Volume 6931 January 2025 Article number A97, 2025) Veronese S.; de Blok W.J.G.; Healy J.; Kleiner D.; Marasco A.; Maccagni F.M.; Kamphuis P.; Brinks E.; Holwerda B.W.; Zabel N.; Chemin L.; Adams E.A.K.; Kurapati S.; Sorgho A.; Spekkens K.; Combes F.; Pisano D.J.; Walter F.; Amram P.; Bigiel F.; Wong O.I.; Athanassoula E.
The observed star formation rates of galaxies in the Local Universe suggests that they are replenishing their gas reservoir across cosmic time. Cosmological simulations predict that this accretion of fresh gas can occur in a hot or a cold mode, yet the existence of low column density (∼1017 cm−2) neutral atomic hydrogen (Hi) tracing the cold mode has not been unambiguously confirmed by observations. We present the application of unconstrained spectral stacking to attempt to detect the emission from this Hi in the circumgalactic medium (CGM) and intergalactic medium (IGM) of six nearby star-forming galaxies from the MHONGOOSE sample for which full-depth observations are available. Our stacking procedure consists of a standard spectral stacking algorithm coupled with a one-dimensional spectral line finder designed to extract a reliable signal close to the noise level. In agreement with previous studies, we find that the amount of signal detected outside the Hi disk is much smaller than implied by simulations. Furthermore, the column density limit that we achieve via stacking (∼1017 cm−2) suggests that direct detection of the neutral CGM and IGM component might be challenging in the future, even with the next generation of radio telescopes. © The Authors 2025
Fermion mass hierarchy and g − 2 anomalies in an extended 3HDM Model
(Springer Science and Business Media Deutschland GmbH, 2021-10) Cárcamo Hernández, A. E.; Kovalenko, Sergey; Maniatis, M.; Schmidt, Ivan
We propose an extension of the three-Higgs-doublet model (3HDM), where the Standard Model (SM) particle content is enlarged by the inclusion of two inert SU2L scalar doublets, three inert and two active electrically neutral gauge singlet scalars, charged vector like fermions and Majorana neutrinos. These additional particles are introduced to generate the SM fermion mass hierarchy from a sequential loop suppression mechanism. In our model the top and exotic fermion masses appear at tree level, whereas the remaining fermions get their masses radiatively. Specifically, bottom, charm, tau and muon masses appear at 1-loop; the masses for the light up, down and strange quarks as well as for the electron at 2-loop and masses for the light active neutrinos at 3-loop. Our model successfully accounts for SM fermion masses and mixings and accommodates the observed Dark Matter relic density, the electron and muon anomalous magnetic moments, as well the constraints arising from charged Lepton Flavor Violating (LFV) processes. The proposed model predicts charged LFV decays within the reach of forthcoming experiments. © 2021, The Author(s).
Search for New Phenomena in Final States with Two Leptons and One or No b -Tagged Jets at s =13 TeV Using the ATLAS Detector
(American Physical Society, 2021-10-01) Aad, G.; Abbott, B.; Abbott, D.C.; Abed Abud, A.; Abeling, K.; Abhayasinghe, D.K.; Abidi, S.H.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Abusleme Hoffman, A.C.; Acharya, B.S.; Achkar, B.; Adam, L.; Adam Bourdarios, C.; Adamczyk, L.; Adamek, L.; Adelman, J.; Adiguzel, A.; Adorni, S.; Adye, T.; Affolder, A.A.; Afik, Y.; Agapopoulou, C.; Agaras, M.N.; Agarwala, J.; Aggarwal, A.; Agheorghiesei, C.; Aguilar-Saavedra, J.A.; Ahmad, A.; Ahmadov, F.; Ahmed, W.S.; Ai, X.; Aielli, G.; Akatsuka, S.; Akbiyik, M.; Åkesson, T.P.A.; Akimov, A.V.; Al Khoury, K.; Alberghi, G.L.; Albert, J.; Alconada Verzini, M.J.; Alderweireldt, S.; Aleksa, M.; Aleksandrov, I.N.; Alexa, C.; Alexopoulos, T.; Alfonsi, A.; Alfonsi, F.; Alhroob, M.; Ali, B.; Ali, S.; Aliev, M.; Alimonti, G.; Allaire, C.; Allbrooke, B.M.M.; Allport, P.P.; Aloisio, A.; Alonso, F.; Alpigiani, C.
A search for new phenomena is presented in final states with two leptons and one or no b-tagged jets. The event selection requires the two leptons to have opposite charge, the same flavor (electrons or muons), and a large invariant mass. The analysis is based on the full run-2 proton-proton collision dataset recorded at a center-of-mass energy of s=13 TeV by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 139 fb-1. No significant deviation from the expected background is observed in the data. Inspired by the B-meson decay anomalies, a four-fermion contact interaction between two quarks (b, s) and two leptons (ee or μμ) is used as a benchmark signal model, which is characterized by the energy scale and coupling, Λ and g∗, respectively. Contact interactions with Λ/g∗ lower than 2.0 (2.4) TeV are excluded for electrons (muons) at the 95% confidence level, still far below the value that is favored by the B-meson decay anomalies. Model-independent limits are set as a function of the minimum dilepton invariant mass, which allow the results to be reinterpreted in various signal scenarios. © 2021 CERN.
Trichromatic color tuning strategy for emission of heterometallic EuIII/TbIII coordination polymers with triazolyl-substituted 4-methyl-phenoxo ligand
(Journal of Rare Earths, 2025, 2025) Perez-Obando, Juliana; Manzur, Jorge; Fuentealba, Pablo; Morales, Jeannette; Vega, Andrés; Costa de Santana, Ricardo; Carneiro Neto, Albano N.; Spodine, Evgenia
This study presents the microwave-assisted synthesis and characterization of a series of heterometallic coordination polymers (HMCPs) with a 4-methyl-2,6-di[(1H-1,2,4-triazol-1-yl)]phenoxo ligand with varying EuIII/TbIII ratios. Single crystal X-ray diffraction reveals a double-chain structure bridged by triazolyl groups. Powder X-ray diffraction confirms the isostructural nature of the synthesized HMCPs. The photophysical properties depend on lanthanide ion concentration and excitation wavelength, leading to a color shift from green to blue as the proportion of TbIII decreases and EuIII increases. White light generation is achieved in the 8/2 EuIII/TbIII HMCP (CIE: 0.293, 0.326) under 335 nm excitation. The study suggests energy transfer from TbIII to EuIII, but both experimental and theoretical calculations indicate that this transfer is orders of magnitude lower than the sensitization through ligand states. © 2024 The Authors
Extrinsic holographic renormalization for a scalar field
(Nuclear Physics B, Volume 1010January 2025 Article number 116758, 2025) Anastasiou, Giorgos; Araya, Ignacio J.; Ávila, Daniel; Güijosa, Alberto; Patiño-López, Sergio
In the context of the holographic correspondence, we introduce a purely extrinsic renormalization prescription, exemplified with the case of a minimally-coupled scalar field in anti-de Sitter (AdS) space. The counterterms depend only on the field and its radial derivatives. This would seem to conflict with the Dirichlet variational principle, but we show that consistency follows from the fact that the asymptotic structure of asymptotically locally AdS spacetimes requires not only the leading, but also all of the subleading non-normalizable modes to be fixed as a boundary condition. Crucially, as seen from a path integral definition of the bulk partition function involved in the standard Gubser-Klevanov-Polyakov-Witten (GKPW) formula, this condition is valid away from the saddle. We find that the extrinsic renormalization prescription is maximally efficient when the scalar field is massless, which is suggestive of a connection with the Kounterterm method for renormalization of pure gravity. © 2024 The Author(s)
Observational Properties of a Bright Type lax SN 2018cni and a Faint Type Iax SN 2020kyg
(Institute of Physics, 2023-08) Singh, Mridweeka; Sahu, Devendra. K.; Dastidar, Raya; Barna, Barnabás; Misra, Kuntal; Gangopadhyay, Anjasha; Howell, D. Andrew; Jha, Saurabh W.; Im, Hyobin; Taggart, Kirsty; Andrews, Jennifer; Hiramatsu, Daichi; Teja, Rishabh Singh; Pellegrino, Craig; Foley, Ryan J.; Joshi, Arti; Anupama G.C.; Bostroem, K. Azalee; Burke, Jamison; Camacho-Neves, Yssavo; Dutta, Anirban; Kwok, Lindsey A. i; McCully, Curtis; Pan, Yen-Chen; Siebert, Matt; Srivastav, Shubham; Szalai, Tamás; Swift, Jonathan J.; Yang, Grace; Zhou, Henry; DiLullo, Nico; Scheer, Jackson
We present the optical photometric and spectroscopic analysis of two Type Iax supernovae (SNe), 2018cni and 2020kyg. SN 2018cni is a bright Type Iax SN (M V,peak = −17.81 ± 0.21 mag), whereas SN 2020kyg (M V,peak = −14.52 ± 0.21 mag) is a faint one. We derive 56Ni mass of 0.07 and 0.002 M ⊙and ejecta mass of 0.48 and 0.14 M ⊙ for SNe 2018cni and 2020kyg, respectively. A combined study of the bright and faint Type Iax SNe in R/r-band reveals that the brighter objects tend to have a longer rise time. However, the correlation between the peak luminosity and decline rate shows that bright and faint Type Iax SNe exhibit distinct behavior. Comparison with standard deflagration models suggests that SN 2018cni is consistent with the deflagration of a CO white dwarf, whereas the properties of SN 2020kyg can be better explained by the deflagration of a hybrid CONe white dwarf. The spectral features of both the SNe point to the presence of similar chemical species but with different mass fractions. Our spectral modeling indicates stratification at the outer layers and mixed inner ejecta for both of the SNe. © 2023. The Author(s). Published by the American Astronomical Society.
Intrinsic metallicity variation in the intermediate mass type ii globular cluster ngc 1261
(Oxford University Press, 2021-10-01) Muñoz, C.; Geisler, D.; Villanova, S.; Sarajedini, Ata; Frelijj, H.; Vargas, C.; Monaco L.; O'connell J.
Globular Clusters (GCs) are now well known to almost universally show multiple populations (MPs). The HST UV Legacy Survey of a large number of Galactic GCs in UV filters optimized to explore MPs finds that a small fraction of GCs, termed Type II, also display more complex, anomalous behaviour. Several well-studied Type II GCs show intrinsic Fe abundance variations, suggesting that the other, less well-studied, Type II GCs should also exhibit similar behaviour. Our aim is to perform the first detailed metallicity analysis of NGC 1261, an intermediate mass Type II GC, in order to determine if this object shows an intrinsic Fe variation. We determined the Fe abundance in eight red giant members using Magellan-MIKE and UVES-FLAMES high-resolution, high S/N spectroscopy. The full range of [Fe/H] for the entire sample from the spectra is from -1.05 to -1.43 dex with an observed spread σobs = 0.133 dex. Compared with the total internal error of σtot = 0.06, this indicates a significant intrinsic metallicity spread of σint = 0.119 dex. We found a very similar variation in [Fe/H] using an independent method to derive the atmospheric parameters based on near-IR photometry. More importantly, the mean metallicity of the five presumed normal metallicity stars is -1.37 ± 0.02, while that of the three presumed anomalous/high metallicity stars is -1.18 ± 0.09. This difference is significant at the ∼2.4σ level. We find indications from existing data of other Type II GCs that several of them presumed to have real metallicity spreads may in fact possess none. The minimum mass required for a GC to acquire an intrinsic Fe spread appears to be ∼105M⊙. We find no strong correlation between mass and metallicity variation for Type II GCs. The metallicity spread is also independent of the fraction of anomalous stars within the Type II GCs and of GC origin. © 2021 The Author(s).
SN 2019hcc: A Type II supernova displaying early O ii lines
(Oxford University Press, 2021-10) Parrag, Eleonora; Inserra, Cosimo; Schulze, Steve; Anderson, Joseph; Chen, Ting-Wan; Leloudas, Giorgios; Galbany, Lluis; Gutiérrez, Claudia P.; Hiramatsu, Daichi; Kankare, Erkki; Müller-Bravo, Tomás E.; Nicholl, Matt; Pignata, Giuliano; Cartier, Regis; Gromadzki, Mariusz; Kozyreva, Alexandra; Rau, Arne; Burke, Jamison; Howell, D. Andrew; Mccully, Curtis; Pellegrino, Craig
We present optical spectroscopy together with ultraviolet, optical, and near-infrared photometry of SN 2019hcc, which resides in a host galaxy at redshift 0.044, displaying a sub-solar metallicity. The supernova spectrum near peak epoch shows a 'w' shape at around 4000 Å which is usually associated with O ii lines and is typical of Type I superluminous supernovae. SN 2019hcc post-peak spectra show a well-developed H α P-Cygni profile from 19 d past maximum and its light curve, in terms of its absolute peak luminosity and evolution, resembles that of a fast-declining Hydrogen-rich supernova (SN IIL). The object does not show any unambiguous sign of interaction as there is no evidence of narrow lines in the spectra or undulations in the light curve. Our tardis spectral modelling of the first spectrum shows that carbon, nitrogen, and oxygen (CNO) at 19 000 K reproduce the 'w' shape and suggests that a combination of non-thermally excited CNO and metal lines at 8000 K could reproduce the feature seen at 4000 Å. The Bolometric light-curve modelling reveals that SN 2019hcc could be fit with a magnetar model, showing a relatively strong magnetic field (B > 3 × 1014 G), which matches the peak luminosity and rise time without powering up the light curve to superluminous luminosities. The high-energy photons produced by the magnetar would then be responsible for the detected O ii lines. As a consequence, SN 2019hcc shows that a 'w' shape profile at around 4000 Å, usually attributed to O ii, is not only shown in superluminous supernovae and hence it should not be treated as the sole evidence of the belonging to such a supernova type. © 2021 The Author(s).
The prevalence of suicide attempt and suicidal ideation and its relationship with aggression and bullying in Chilean adolescents
(Frontiers in Psychology, Volume 142023 Article number 1133916, 2023) Veloso-Besio, Constanza; Cuadra-Peralta, Alejandro; Gallardo-Peralta, Lorena; Cuadra-Fernandez, Pascal; Quiroz, Pedro Trujillo; Troncoso, Nicole Vega
Background: Suicide constitutes one of the main mental health problems worldwide, requiring detection, and prevention efforts, especially in the adolescent population. Objective: The purpose of this study was to estimate the prevalence of suicide attempts and suicidal ideation and their relationship with aggressiveness and bullying in Chilean adolescents. Materials and methods: The sample was composed of 728 adolescents schooled from Arica city: 56.6% were males and 43.4% were females. The students attended from de 1st to the 4th year of secondary. The average age of the sample was 15,6 years. The following instruments were used: Okasha’s Suicidality Scale, Buss and Perry’s Aggressiveness Survey, and the Social Acceptance (School Bullying) sub-test of the Kidscreen-52 Survey. A cross-sectional, descriptive, and correlational design was applied. The sampling was non-probabilistic for convenience. Results: 18.4% of the students reported that they had attempted suicide and 65.6% reported that they had suicidal ideation. The prevalence of suicide attempts was higher than in male adolescents (29,1% vs. 10,2%), and the same prevalence was for suicidal ideation (76,6% vs. 57,3%). Suicide attempts and suicidal ideation were positively and significantly correlated with aggressiveness (r = 0.32, r = 0.48) and bullying (r = 0.37, r = 0.50). Conclusion: The prevalence of suicide attempts and suicidal ideation is both higher in girls than boys. In this sense, girls constitute a risk group. In addition, this study provides evidence that supports the relationship between suicide attempts and suicidal ideation. The results highlight the role that educational institutions should have in terms of prevention and effective approaches. Copyright © 2023 Cuadra-Peralta, Veloso-Besio, Gallardo-Peralta, Cuadra-Fernandez, Quiroz and Troncoso.
Probing the explanation of the muon (g-2) anomaly and thermal light dark matter with the semi-visible dark photon channel
(Springer Science and Business Media Deutschland GmbH, 2021-10) Cazzaniga, C.; Odagiu, P.; Depero, E.; Molina Bueno, L.; Andreev, Yu. M.; Banerjee, D.; Bernhard, J.; Burtsev, V.E.; Charitonidis, N.; Chumakov, A.G.; Cooke, D.; Crivelli, P.; Dermenev, A.V.; Donskov, S.V.; Dusaev, R.R.; Enik, T.; Feshchenko, A.; Frolov, V.N.; Gardikiotis, A.; Gerassimov, S.G.; Girod, S.; Gninenko, S.N.; Hösgen, M.; Kachanov, V.A.; Karneyeu, A.E.; Kekelidze, G.; Ketzer, B.; Kirpichnikov, D.V.; Kirsanov, M.M.; Kolosov, V.N.; Konorov, I.V.; Kovalenko, S.G.; Kramarenko, V.A.; Kravchuk, L.V.; Krasnikov, N.V.; Kuleshov, S.V.; Lyubovitskij, V.E.; Lysan, V.; Matveev, V.A.; Mikhailov, Yu. V.; Peshekhonov, D.V.; Polyakov, V.A.; Radics, B.; Rojas, R.; Rubbia, A.; Samoylenko, V.D.; Shchukin, D.; Sieber, H.; Tikhomirov, V.O.; Tlisova, I.V.; Tlisov, D.A.; Toropin, A.N.; Trifonov, A. Yu.; Vasilishin, B.I.; Arenas, G. Vasquez; Volkov P.V.; Volkov, V. Yu.; Ulloa P.
We report the results of a search for a new vector boson (A′) decaying into two dark matter particles χ1χ2 of different mass. The heavier χ2 particle subsequently decays to χ1 and an off-shell Dark Photon A′ ∗→ e+e-. For a sufficiently large mass splitting, this model can explain in terms of new physics the recently confirmed discrepancy observed in the muon anomalous magnetic moment at Fermilab. Remarkably, it also predicts the observed yield of thermal dark matter relic abundance. A detailed Monte-Carlo simulation was used to determine the signal yield and detection efficiency for this channel in the NA64 setup. The results were obtained re-analyzing the previous NA64 searches for an invisible decay A′→ χχ¯ and axion-like or pseudo-scalar particles a→ γγ. With this method, we exclude a significant portion of the parameter space justifying the muon g-2 anomaly and being compatible with the observed dark matter relic density for A′ masses from 2me up to 390 MeV and mixing parameter ε between 3 × 10 - 5 and 2 × 10 - 2. © 2021, The Author(s).
Regioselective cyclocondensations with thiobarbituric acid: spirocyclic and azocine products, X-ray characterization, and antioxidant evaluation
(Royal Society of Chemistry, 0025-03) Polo-Cuadrado, Efraín; Acosta-Quiroga, Karen; Rojas-Peña, Cristian; Rodriguez-Nuñez, Yeray A; Blanco-Acuña, Edgard Fabián; Lopez, Jhon J.; Brito, Iván; Cisterna, Jonathan; Alderete, Joel B.; Gutiérrez, Margarita
Multicomponent cyclocondensations of 5-amino-3-methyl-1-phenyl-1H-pyrazole (AMPZ), thiobarbituric acid, and p-formaldehyde under conventional thermal heating or ultrasonic irradiation were studied. Treatment of the reaction mixture in ethanol in an ultrasonic bath for 3 h produced azocine compound 4b, while the same mixture in ethanol under reflux conditions for 15 h produced spiro compound 4a. This work encompasses intricate experimental details, X-ray diffraction measurements, and multifaceted computational analyses employing methods such as the density functional theory and Hirshfeld surface analysis. Crystallographic investigations revealed the molecular structure of the compound and clarified its interactions involving hydrogen bonds and weak intermolecular forces. This article describes the synthesis and characterization of a novel spirocyclic compound. The study also evaluated the antioxidant potential in vitro using the DPPH and ABTS methods. The results showed that these compounds showed the best free radical scavenging ability, even in very small amounts, and that even at very low concentrations, these compounds showed excellent radical scavenging potential. Surprisingly, these compounds exhibited strong (ABTS+) radical scavenging activities, mainly attributed to the HAT mechanism, indicating their potential as therapeutic agents. Facile multipurpose, three-component selective procedures for new spiroheterocycles have been proposed, presenting intriguing perspectives in the field of medicine, particularly in the field of antioxidants. The geometric values of the computationally optimized structure were calculated using the density functional theory in LC-BLYP/6-31(d), aligned with the X-ray diffraction data, reinforcing the precision of our findings. © 2025 The Royal Society of Chemistry
Metodología para evaluar la exposición ocupacional a contaminantes químicos en altitud
(Academy of Medical and Health Sciences of Catalonia and the Balearic Islands, 2021-10-15) Zamora-Saa, Margarita; Zamora-Saa, Jilberto
Este artículo examina el actual método para evaluar la exposición a contaminantes químicos en altitud usando los Threshold Limit Value (TLV). Estos valores son establecidos para trabajos a nivel del mar en jornadas de 8 horas diarias y 40 horas semanales. Se analiza este problema aplicándolo a un grupo específico de mineros chilenos que trabaja sobre los 3000 m con jornadas excepcionales de 12 horas diarias. Se comparan dos alternativas para evaluar la exposición a contaminantes químicos: ajustes al TLV en altitud, y el cálculo de la dosis inhalada. Puesto que la ventilación por minuto es el parámetro fisiológico que cambia en altitud se propone y fundamenta como método de evaluación el cálculo de la dosis inhalada del contaminante químico.
Heterometallic coordination polymers based on CuII/LnIII cations. Solid-state and magnetic characterization
(Academic Press Inc., 2021-11) Baldo, Bianca; Bataille, Thierry; Venegas-Yazigi, Diego; Audebrand, Nathalie; Paredes-García, Verónica
Novel heterometallic three-dimensional coordination polymers {[CuII2LnIIICl2(HIA)4(NO3)(DMF)2]∙(2DMF)∙(H2O)}n based on Ce (1), Eu (2) or Gd (3) and imidazole-4-acrylic acid (H2IA), were successfully synthesized using the sonochemical method. All attempts to obtain the compound using other synthetic methods were unsuccessful. The heterometallic polymers are isostructural, crystallizing in the chiral P3221 trigonal space group. The crystal structures correspond to an intricated 3D framework where the Cu(HIA)2 fragments generate two interpenetrated copper (II) networks, [Cu(HIA)2]n. The LnIII cations that interact with these CuII-networks through the carboxylate group belonging to the organic ligand confer a higher complexity to the 3D network. Additionally, the coordination environment around the copper (II) cations is responsible for the chirality of the structures, making these even more exciting. The three-dimensional polymers were also characterized from a magnetic point of view, obtaining for (1) and (2) antiferromagnetic interactions, while for (3) a ferromagnetic interaction was observed. Furthermore, to the best of our knowledge, these coordination polymers are the first heterometallic compounds based on 3d/4f cations, assembled by the ligand imidazole-4-acrylate (HIA−). © 2021 Elsevier Inc.
MINCE: III. Detailed chemical analysis of the UVES sample
(EDP Sciences, 0025-03) Lucertini F.; Sbordone L.; Caffau E.; Bonifacio P; Monaco L; Cescutti G; Lallement R.; François P. b; Spitoni E.; Hansen C.J; Korn A.J.; Kučinskas A
Context. The Measuring at Intermediate Metallicity Neutron-Capture Elements (MINCE) project aims to provide high-quality neutron-capture abundances measurements for several hundred stars at an intermediate metallicity of -2.5 < [Fe/H] < -1.5. This project will shed light on the origin of the neutron-capture elements and the chemical enrichment of the Milky Way. Aims. The goal of this work is to chemically characterize the second sample of the MINCE project and compare the abundances with the galactic chemical evolution model at our disposal. Methods. We performed a standard abundance analysis based on one-dimensional (1D) local thermodynamic equilibrium (LTE) model atmospheres based on high-resolution and high-signal-to-noise-ratio (S/N) spectra from Ultraviolet and Visual Echelle Spectrograph (UVES). Results. We provide the kinematic classification (i.e., thin disk, thick disk, thin-to-thick disk, halo, Gaia Sausage Enceladus, Sequoia) of 99 stars and the atmospheric parameters for almost all stars. We derived the abundances for light elements (from Na to Zn) and neutron-capture elements (Rb, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, and Eu) for a subsample of 32 stars in the metallicity range of -2.5 < [Fe/H] < -1.00. In the subsample of 32 stars, we identified eight active stars exhibiting (inverse) P-Cygni profile and one Li-rich star, CD 28-11039. We find a general agreement between the chemical abundances and the stochastic model computed for the chemical evolution of the Milky Way halo for elements Mg, Ca, Si, Ti, Sc, Mn, Co, Ni, Zn, Rb, Sr, Y, Zr, Ba, La, and Eu. Conclusions. The MINCE project has already significantly increased the number of neutron-capture elements measurements in the intermediate metallicity range. The results from this sample are in perfect agreement with the previous MINCE sample. The good agreement between the chemical abundances and the chemical evolution model of the Galaxy supports the nucleosynthetic processes adopted to describe the origin of the n-capture elements. © The Authors 2025.
ODIN: High Clustering Strength of Protoclusters at Cosmic Noon
(Institute of Physics, 0025-04) Ramakrishnan, Vandana; Lee, Kyoung-Soo; Firestone, Nicole; Gawiser, Eric; Artale, Maria Celeste; Gronwall, Caryl; Guaita, Lucia; Hwang, Ho Seong; Im, Sang Hyeok; Jeong, Woong-Seob; Kim, Seongjae; Kumar, Ankit
The One-hundred-deg2 DECam Imaging in Narrowbands (ODIN) survey is carrying out a systematic search for protoclusters during Cosmic Noon, using Lyα-emitting galaxies (LAEs) as tracers. Once completed, ODIN aims to identify hundreds of protoclusters at redshifts of 2.4, 3.1, and 4.5 across seven extragalactic fields, covering a total area of up to 91 deg2. In this work, we report the high clustering strength of the ODIN protoclusters, determined via measurements of their cross-correlation with LAEs. Our sample consists of 150 protocluster candidates at z = 2.4 and 3.1, identified in two ODIN fields with a total area of 13.9 deg2. At z = 2.4 and 3.1, the inferred protocluster biases are 6 . 6 − 1.1 + 1.3 and 6 . 1 − 1.1 + 1.3 , corresponding to mean halo masses of log 〈 M / M ⊙ 〉 = 13.5 3 − 0.24 + 0.21 and 12.9 6 − 0.33 + 0.28 , respectively. By the present day, these protoclusters are expected to evolve into virialized galaxy clusters with a mean mass of ∼1014.5 M⊙. By comparing the observed number density of protoclusters to that of halos with the same measured clustering strength, we find that the completeness of our sample is of order unity. Finally, the similar descendant masses derived for our samples at z = 2.4 and 3.1, assuming that the halo number density remains constant, suggest that they represent similar structures observed at different cosmic epochs. As a consequence, any observed differences between the two samples can be understood as redshift evolution. The ODIN protocluster samples will thus provide valuable insights into the cosmic evolution of cluster galaxies. © 2025. The Author(s). Published by the American Astronomical Society.

Examinar

Envíos recientes