Estudio de una estructura metamaterial quiral mediante una simulación numérica

Los metamateriales son medios artificiales que presentan propiedades electromagnéticas no encontradas en medios naturales. Lo especial de estos medios es que sus propiedades no se deben a sus componentes que lo forman si no a la estructura determinada que posean. Esto hace real la posibilidad de crear materiales a medida con propiedades conocidas en rangos de frecuencia nuevos, o incluso nuevas propiedades como índices de refracción negativos. En este trabajo nos centraremos en las estructuras conocidas como quirales, capaces de producir actividad electromagnética y dicroismo circular. Haremos un repaso del desarrollo de estas estructuras y un estudio de una en concreto mediante simulación numérica. El estudio se hará en un programa de simulación electromagnética tridimensional que nos posibilitará diseñar la estructura y analizar la propagación en ella. Utilizaremos los datos que nos proporciona el programa para obtener información sobre el medio, así como alguno de sus parámetros característicos.Grado en Físic

Definition of a FPGA-based SoC architecture for PRBS transmission in optical spectroscopy

Optical spectroscopy is a well-known tool typically employed for characterizing the properties of materials by analyzing their iteration with light. One of the most spread techniques is the dual comb spectroscopy, since it accomplishes ultra-high resolution, and high sensitivity measurements with a relatively simple platform including a single, relatively narrowband photodetector. The employed optical dual comb can be implemented through electro-optical (EO) modulation driven by pseudo-ransom binary sequences (PRBS) at high data rates, commonly in the range of tens of Gbps. For that purpose, the runtime generation and transmission of adaptive PRBS is still an open challenge, often involving expensive and not flexible high-speed digital systems, with a few commercially available solutions that sometimes do not match the application requirements efficiently. In this context, this work describes the definition and implementation of a System-on-Chip (SoC) architecture, based on a FPGA device, capable of generating and transmitting two PRBS for a dual comb, at a data rate up to 5 Gbps. The architecture can be configured and its operation modified in run time, thanks to the general-purpose processor involved, in charge of managing an Ethernet link to receive new PRBS to be transmitted or set up certain parameters. The proposed design has been validated experimentally on a dual comb spectroscopy measurement, where the absorption of a hydrogen cyanide (HCN) gas cell has been successfully characterized.Agencia Estatal de InvestigaciónMinisterio de Ciencia e Innovació

The Caldera. No. 23

La pandemia, sin lugar a dudas, nos ha cambiado la vida a todos; un viernes nos fuimos para nuestros hogares, en el marco de una educación presencial; al lunes siguiente, después de dos días, estábamos iniciando el camino hacia una educación remota, una educación virtual, que se ha convertido en una gran alternativa para seguir contribuyendo con la formación de nuestros niños y jóvenes caldistas y al mejoramiento de nuestra calidad de vida que halla, en la educación, nuevamente la respuesta; han sido meses de cambios drásticos, inimaginables pero, cambios positivos que nos han permitido crecer como individuos, como familia, como escuela y como sociedad.Especial pandemia. Una generación Resiliente por promoción DINASTIA…06 VII Concurso Intercolegiado departamental de Oratoria. Ulibro 2020…51 Deporte en el Caldas…64 Expresiones Caldistas…71 Celebremos la palabra…93 Nuestros Maestros…102 Galería de Imágenes…107The pandemic, without a doubt, has changed the lives of all of us; One Friday we went to our homes, as part of a face-to-face education; The following Monday, after two days, we were starting the path towards a remote education, a virtual education, which has become a great alternative to continue contributing to the training of our children and young Caldistas and to the improvement of our quality of life. that finds, in education, the answer again; They have been months of drastic changes, unimaginable but positive changes that have allowed us to grow as individuals, as a family, as a school and as a society

A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

Dynamic curvature sensing using time expanded PhiOTDR

Shape sensing can be accomplished using optical fiber sensors through different interrogation principles such as fiber Bragg gratings, optical frequency-domain reflectometry (OFDR), or optical time-domain reflectometry (OTDR). These techniques are either not entirely distributed, have poor performance in dynamic sensing, or are only valid for few-meter-long fibers. Here, we present a system able to perform distributed curvature sensing with a range of 125 m, 10-cm resolution, and a sampling rate of 50 Hz. This is done by interrogating three cores of a multi-core fiber (MCF) with the novel time-expanded phase-sensitive (TE-?)OTDR technique. This system fills a performance gap in fiber shape sensors, opening the door to applications in civil engineering, medicine, or seismolog

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit