Low-Scaling GW Algorithm Applied to Twisted Transition-Metal Dichalcogenide Heterobilayers.

The GW method is widely used for calculating the electronic band structure of materials. The high computational cost of GW algorithms prohibits their application to many systems of interest. We present a periodic, low-scaling, and highly efficient GW algorithm that benefits from the locality of the Gaussian basis and the polarizability. The algorithm enables G0W0 calculations on a MoSe2/WS2 bilayer with 984 atoms per unit cell, in 42 h using 1536 cores. This is 4 orders of magnitude faster than a plane-wave G0W0 algorithm, allowing for unprecedented computational studies of electronic excitations at the nanoscale.

Recomendación del Comité Asesor de Vacunas y Estrategias de Inmunización (CAVEI) sobre vacunación contra viruela símica en Chile / Recommendation of the Advisory Committee on Vaccines and Immunization Strategies on monkeypox vaccination in Chile

La viruela del mono fue declarada emergencia de salud pública de importancia internacional por la Organización Mundial de la Salud el año 2022. En Chile, hasta septiembre se han confirmado sobre 450 enfermos, mayoritariamente hombres jóvenes. Este poxvirus zoonótico se transmite entre humanos por contacto estrecho; la enfermedad es autolimitada y puede ser fatal en inmunocomprometidos. La prevención mediante inmunización es importante. MVA-BN es una de las tres vacunas disponibles, de 3° generación, contiene el virus vaccinia atenuado, no replicante por lo que se puede administrar a pacientes inmunocomprometidos y mujeres embarazadas y está aprobada para viruela símica en personas > 18 años. La información disponible sobre eficacia y efectividad es limitada. El CAVEI recomienda incorporar esta vacuna para interrumpir la cadena de transmisión y reducir el riesgo de enfermedad grave, en dos dosis separadas por 28 días, por vía subcutánea, priorizando el uso post-exposición para contactos estrechos con riesgo de enfermedad grave, idealmente en los primeros 4 días y hasta 14 días post contacto de riesgo y en ausencia de síntomas. Cuando el suministro de vacunas lo permita, se recomienda prevención pre-exposición para personas con alto riesgo ocupacional o por prácticas sexuales. Esta recomendación podría modificarse según la epidemiología, el suministro de vacunas y nueva información científica.

Monkeypox was declared a public health emergency of international concern by the World Health Organization during 2022. In Chile, over 450 patients have been confirmed until September, mostly young men. This zoonotic poxvirus is transmitted from humans to humans through close contact; it is a self-limiting disease and can be fatal in people with immunodeficiency. Prevention by immunization is important. MVA-BN, one of the three vaccines available, it is a third generation vaccine, based on non-replicating modified vaccinia virus, therefore can be administered to immunocompromised patients and pregnant women and it has been approved for monkeypox in people over 18 years of age. The available information on efficacy and effectiveness is limited. The CAVEI recommends incorporating this vaccine to interrupt the chain of transmission and reduce the risk of severe disease, administered subcutaneously in two doses, 28 days apart, prioritizing post exposure use for close contacts of confirmed cases with risk of severe disease, ideally within 4 days of exposure and it can be used up to 14 days after exposure and in the absence of symptoms. When the vaccine supply allows it, its application is recommended as pre-exposure prevention for people with high-risk sexual practices or with occupational risk. This recommendation could be modified according to epidemiology, vaccines supply and new scientific information.

Highly conducting single-molecule topological insulators based on mono- and di-radical cations.

Single-molecule topological insulators are promising candidates as conducting wires over nanometre length scales. A key advantage is their ability to exhibit quasi-metallic transport, in contrast to conjugated molecular wires which typically exhibit a low conductance that decays as the wire length increases. Here, we study a family of oligophenylene-bridged bis(triarylamines) with tunable and stable mono- or di-radicaloid character. These wires can undergo one- and two-electron chemical oxidations to the corresponding mono-cation and di-cation, respectively. We show that the oxidized wires exhibit reversed conductance decay with increasing length, consistent with the expectation for Su-Schrieffer-Heeger-type one-dimensional topological insulators. The 2.6-nm-long di-cation reported here displays a conductance greater than 0.1G0, where G0 is the conductance quantum, a factor of 5,400 greater than the neutral form. The observed conductance-length relationship is similar between the mono-cation and di-cation series. Density functional theory calculations elucidate how the frontier orbitals and delocalization of radicals facilitate the observed non-classical quasi-metallic behaviour.

Growth Optimization and Device Integration of Narrow-Bandgap Graphene Nanoribbons.

The electronic, optical, and magnetic properties of graphene nanoribbons (GNRs) can be engineered by controlling their edge structure and width with atomic precision through bottom-up fabrication based on molecular precursors. This approach offers a unique platform for all-carbon electronic devices but requires careful optimization of the growth conditions to match structural requirements for successful device integration, with GNR length being the most critical parameter. In this work, the growth, characterization, and device integration of 5-atom wide armchair GNRs (5-AGNRs) are studied, which are expected to have an optimal bandgap as active material in switching devices. 5-AGNRs are obtained via on-surface synthesis under ultrahigh vacuum conditions from Br- and I-substituted precursors. It is shown that the use of I-substituted precursors and the optimization of the initial precursor coverage quintupled the average 5-AGNR length. This significant length increase allowed the integration of 5-AGNRs into devices and the realization of the first field-effect transistor based on narrow bandgap AGNRs that shows switching behavior at room temperature. The study highlights that the optimized growth protocols can successfully bridge between the sub-nanometer scale, where atomic precision is needed to control the electronic properties, and the scale of tens of nanometers relevant for successful device integration of GNRs.

Pseudotumor toraco-abdominal asociado a Bartonella henselae y Eikenella corrodens en un paciente pediátrico inmunocompetente / Thoraco-abdominal pseudotumor associated with Bartonella henselae and Eikenella corrodens in an immunocompetent patient

Resumen Los pseudotumores inflamatorios son poco frecuentes y escasamente descritos en la literatura y han sido asociados a infecciones polimicrobianas. Se presenta el caso de un niño de 9 años, procedente de Bolivia, quien consultó por dolor abdominal, baja de peso y vómitos, diagnosticándose un pseudotumor tóraco-abdominal. El laboratorio clínico, mediante el estudio de biología molecular en tejido, permitió la identificación de uno de los probables agentes etiológicos.

Abstract Inflammatory pseudotumors are a rare pathology and scarcely reported in the literature and have been associated with polymicrobial infections. Here, we present the case of a 9 years old boy from Bolivia, who presented with abdominal pain, weight loss and vomiting, who was diagnosed with a thoraco-abdominal pseudotumor. The micro-biology and molecular laboratories in tissue allowed the identification of one of the probable etiological agents.

Influence of Zirconia and Organic Additives on Mechanical and Electrochemical Properties of Silica Sol-Gel Coatings.

This paper presents the result of the investigation of organically modified silica (ORMOSIL)-zirconia coatings used to enhance their protective properties, namely corrosion and scratch resistance. Two different materials, i.e., SiO2/ZrO2 and SiO2/GPTMS/ZrO2, were synthesized, measured, and analyzed to find the difference in the used organosilane precursor (dimethyldiethoxysilane and (3-glycidoxypropyl)trimethoxysilane, respectively). SiO2/ZrO2 coatings showed higher hardness than SiO2/GPTMS/ZrO2. Moreover, the value of polarization resistance (Rp) for SiO2/GPTMS/ZrO2 coated 316L steel relative to the uncoated one was obtained. It was nearly 84 times higher. The coating delamination was observed with load 16N. Additionally, the corrosion mitigation for 316L coated by SiO2/GPTMS/ZrO2 was observed even after extended exposure to corrosion agents.

Low-Scaling GW with Benchmark Accuracy and Application to Phosphorene Nanosheets.

GW is an accurate method for computing electron addition and removal energies of molecules and solids. In a conventional GW implementation, however, its computational cost is O(N4) in the system size N, which prohibits its application to many systems of interest. We present a low-scaling GW algorithm with notably improved accuracy compared to our previous algorithm [J. Phys. Chem. Lett. 2018, 9, 306-312]. This is demonstrated for frontier orbitals using the GW100 benchmark set, for which our algorithm yields a mean absolute deviation of only 6 meV with respect to canonical implementations. We show that also excitations of deep valence, semicore, and unbound states match conventional schemes within 0.1 eV. The high accuracy is achieved by using minimax grids with 30 grid points and the resolution of the identity with the truncated Coulomb metric. We apply the low-scaling GW algorithm with improved accuracy to phosphorene nanosheets of increasing size. We find that their fundamental gap is strongly size-dependent varying from 4.0 eV (1.8 nm × 1.3 nm, 88 atoms) to 2.4 eV (6.9 nm × 4.8 nm, 990 atoms) at the evGW0@PBE level.

[Thoraco-abdominal pseudotumor associated with Bartonella henselae and Eikenella corrodens in an immunocompetent patient]. / Pseudotumor toraco-abdominal asociado a Bartonella henselae y Eikenella corrodens en un paciente pediátrico inmunocompetente.

Inflammatory pseudotumors are a rare pathology and scarcely reported in the literature and have been associated with polymicrobial infections. Here, we present the case of a 9 years old boy from Bolivia, who presented with abdominal pain, weight loss and vomiting, who was diagnosed with a thoraco-abdominal pseudotumor. The micro-biology and molecular laboratories in tissue allowed the identification of one of the probable etiological agents.

Comparison of VSV Pseudovirus and Focus Reduction Neutralization Assays for Measurement of Anti-Andes orthohantavirus Neutralizing Antibodies in Patient Samples.

Andes orthohantavirus (ANDV) is the etiologic agent of hantavirus cardiopulmonary syndrome (HCPS), which has a case fatality rate around 35%, with no effective treatment or vaccine available. ANDV neutralizing antibody (NAb) measurements are important for the evaluation of the immune response following infection, vaccination, or passive administration of investigational monoclonal or polyclonal antibodies. The standard assay for NAb measurement is a focus reduction neutralization test (FRNT) featuring live ANDV and must be completed under biosafety level (BSL)-3 conditions. In this study, we compared neutralization assays featuring infectious ANDV or vesicular stomatitis virus (VSV) pseudovirions decorated with ANDV glycoproteins for their ability to measure anti-ANDV NAbs from patient samples. Our studies demonstrate that VSV pseudovirions effectively measure NAb from clinical samples and have greater sensitivity compared to FRNT with live ANDV. Importantly, the pseudovirus assay requires less labor and sample materials and can be conducted at BSL-2.