Optical transitions and excitonic recombination in InAs/InP self-assembled quantum wires

InAs self-assembled quantum wire structures have been grown on InP substrates and studied by means of photoluminescence and polarized-light absorption measurements. According to our calculations, the observed optical transitions in each sample are consistent with wires of different heights, namely from 6 to 13 monolayers. The nonradiative mechanism limiting the emission intensity at room temperature is related to thermal escape of carriers out of the wires.This work has been supported under project No. TIC99-1035-C02 of the Spanish CICYT.Peer reviewe

Engineering Iron Oxide Nanoparticles for Clinical Settings

Iron oxide nanoparticles (IONPs) occupy a privileged position among magnetic nanomaterials with potential applications in medicine and biology. They have been widely used in preclinical experiments for imaging contrast enhancement, magnetic resonance, immunoassays, cell tracking, tissue repair, magnetic hyperthermia and drug delivery. Despite these promising results, their successful translation into a clinical setting is strongly dependent upon their physicochemical properties, toxicity and functionalization possibilities. Currently, IONPs-based medical applications are limited to the use of non-functionalized IONPs smaller than 100 nm, with overall narrow particle size distribution, so that the particles have uniform physical and chemical properties. However, the main entry of IONPs into the scene of medical application will surely arise from their functionalization possibilities that will provide them with the capacity to target specific cells within the body, and hence to play a role in the development of specific therapies. In this review, we offer an overview of their basic physicochemical design parameters, giving an account of the progress made in their functionalization and current clinical applications. We place special emphasis on past and present clinical trials

π-Stacking Isomerism in Polycyclic Aromatic Hydrocarbons: The 2-Naphthalenethiol Dimer

Producción Científicaπ-Stacking is a common descriptor for face-to-face attractive forces between aromatic hydrocarbons. However, the physical origin of this interaction remains debatable. Here we examined π-stacking in a model homodimer formed by two thiol-substituted naphthalene rings. Two isomers of the 2-naphthalenethiol dimer were discovered using rotational spectroscopy, sharing a parallel-displaced crossed orientation and absence of thiol–thiol hydrogen bonds. One of the isomers presents C2 symmetry, structurally analogous to the global minimum of the naphthalene dimer. The experimental data were rationalized with molecular orbital calculations, revealing a shallow potential energy surface. Noncovalent interactions are dominated by dispersion forces according to SAPT energy decomposition. In addition, the reduced electronic density shows a diffuse and extended region of inter-ring interactions, compatible with the description of π-stacking as a competition between dispersion and Pauli repulsion forces

Voltage tuning of exciton topology and g-factor in type-II InAs/GaAsSb quantum dots

Trabajo presentado en la DPG Conference - Geometry and Topology Controlled Nanoarchitectures, celebrada en Berlín (alemania), del 11 al 16 de marzo de 2018Peer reviewe

Type-II Quantum Dots with Topology Driven g-factor tunability

Trabajo presentado en el ICSNN2018: 20th International Conference on Superlattices Nanostructures and Nanodevices, celebrado en Madrid del 23 al 27 de julio de 2018Peer reviewe

Immunogenic dynamics and SARS-CoV-2 variant neutralisation of the heterologous ChAdOx1-S/BNT162b2 vaccination: Secondary analysis of the randomised CombiVacS study

Background: The CombiVacS study was designed to assess immunogenicity and reactogenicity of the heterologous ChAdOx1-S/BNT162b2 combination, and 14-day results showed a strong immune response. The present secondary analysis addresses the evolution of humoral and cellular response up to day 180. Methods: Between April 24 and 30, 2021, 676 adults primed with ChAdOx1-S were enrolled in five hospitals in Spain, and randomised to receive BNT162b2 as second dose (interventional group [IG]) or no vaccine (control group [CG]). Individuals from CG received BNT162b2 as second dose and also on day 28, as planned based on favourable results on day 14. Humoral immunogenicity, measured by immunoassay for SARS-CoV-2 receptor binding domain (RBD), antibody functionality using pseudovirus neutralisation assays for the reference (G614), Alpha, Beta, Delta, and Omicron variants, as well as cellular immune response using interferon-γ and IL-2 immunoassays were assessed at day 28 after BNT162b2 in both groups, at day 90 (planned only in the interventional group) and at day 180 (laboratory data cut-off on Nov 19, 2021). This study was registered with EudraCT (2021-001978-37) and ClinicalTrials.gov (NCT04860739). Findings: In this secondary analysis, 664 individuals (441 from IG and 223 from CG) were included. At day 28 post vaccine, geometric mean titres (GMT) of RBD antibodies were 5616·91 BAU/mL (95% CI 5296·49-5956·71) in the IG and 7298·22 BAU/mL (6739·41-7903·37) in the CG (p 1:100 at day 180 (19% and 22%, respectively). Interpretation: Titres of RBD antibodies decay over time, similar to homologous regimes. Our findings suggested that delaying administration of the second dose did not have a detrimental effect after vaccination and may have improved the response obtained. Lower neutralisation was observed against Omicron and Beta variants at day 180.Funded by Instituto de Salud Carlos III (ISCIII). AMB, AJC, JO, and JF are members of the VACCELERATE (European Corona Vaccine Trial Accelerator Platform) Network, which aims to facilitate and accelerate the design and implementation of COVID-19 phase 2 and 3 vaccine trials. JO is a member of the INsTRuCT (Innovative Training in Myeloid Regulatory Cell Therapy) Consortium, a network of European scientists from academia and industry focused on developing innovative immunotherapies. This work is funded by Instituto de Salud Carlos III, a Spanish public body assigned to the Ministry of Science and Innovation that manages and promotes public clinical research related to public health. The Spanish Clinical Trials Platform is a public network funded by the Instituto de Salud Carlos III (grant numbers PTC20/00018 and PT17/0017), the State Plan for Research, Development, and Innovation 2013−16, the State Plan for Scientific and Technical Research and Innovation 2017−20, and the Subdirectorate General for Evaluation and Promotion of Research, Instituto de Salud Carlos III, cofinanced with FEDER funds. CombiVacS was designed under the umbrella of the VACCELERATE project. VACCELER ATE and INsTRuCT received funding from the EU’s Horizon 2020 Research and Innovation Programme (grant agreement numbers 101037867 and 860003). The Instituto de Salud Carlos III is the Spanish partner in the VACCELERATE project. This work is partially funded by Institute of Health Carlos III (Instituto de Salud Carlos III − ISCIII −), (grants PI19CIII/00004 to JA and PI21CIII/00025 to MPO and JGP), and COVID-19 FUND (grants COV20/00679 and COV20/00072 to MPO and JA) and CIBERINFEC, co-financed by the European Regional Development Fund (FEDER) “A way to make Europe”. The authors thank all trial participants, the international data safety monitoring board (Appendix 1 p 23), and the trial steering committee (Appendix 1 pp 24−25). The authors thank Esther Prieto for editorial assistance and writing support (employed by Hospital Universitario La Paz; funded by the Instituto de Salud Carlos III, grant number PCT20/00018) and María Castillo-de la Osa (PEJ2018-004557-A) for excellent technical assistance.S

Congenital extrahepatic portosystemic shunts (Abernethy malformation): An international observational study

Congenital extrahepatic portosystemic shunt (CEPS) or Abernethy malformation is a rare condition in which splanchnic venous blood bypasses the liver draining directly into systemic circulation through a congenital shunt. Patients may develop hepatic encephalopathy (HE), pulmonary hypertension (PaHT), or liver tumors, among other complications. However, the actual incidence of such complications is unknown, mainly because of the lack of a protocolized approach to these patients. This study characterizes the clinical manifestations and outcome of a large cohort of CEPS patients with the aim of proposing a guide for their management. This is an observational, multicenter, international study. Sixty-six patients were included; median age at the end of follow-up was 30 years. Nineteen patients (28%) presented HE. Ten-, 20-, and 30-year HE incidence rates were 13%, 24%, and 28%, respectively. No clinical factors predicted HE. Twenty-five patients had benign nodular lesions. Ten patients developed adenomas (median age, 18 years), and another 8 developed HCC (median age, 39 years). Of 10 patients with dyspnea, PaHT was diagnosed in 8 and hepatopulmonary syndrome in 2. Pulmonary complications were only screened for in 19 asymptomatic patients, and PaHT was identified in 2. Six patients underwent liver transplantation for hepatocellular carcinoma or adenoma. Shunt closure was performed in 15 patients with improvement/stability/cure of CEPS manifestations. Conclusion: CEPS patients may develop severe complications. Screening for asymptomatic complications and close surveillance is needed. Shunt closure should be considered both as a therapeutic and prophylactic approach

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements