Fresnel polarisation of infra-red radiation by elemental bismuth

We revisit the classical problem of electromagnetic wave refraction from a lossless dielectric to a lossy conductor, where both media are considered to be non-magnetic, linear, isotropic and homogeneous. We derive the Fresnel coefficients of the system and the Poynting vectors at the interface, in order to compute the reflectance and transmittance of the system. We use a particular parametrisation of the referred Fresnel coefficients so as to make a connection with the ones obtained for refraction by an interface between two lossless media. This analysis allows the discussion of an actual application, namely the Fresnel polarisation of infra-red radiation by elemental bismuth, based on the concept of pseudo Brewster’s angle.We acknowledge helpful discussions with M. Vasilevskiy, P. Alpuim, J. Caridad and B. Figueiredo. The authors thank the European Structural and Investment Funds in the FEDER component, through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020) [under the Project GNESIS -Graphenest's New Engineered System and its Implementation Solutions; Funding Reference: POCI-01-0247-FEDER-033566], European Regional Development Fund. This work was also supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2019

Management of early melanoma recurrence despite adjuvant anti-PD-1 antibody therapy

Background: Anti-programmed cell death protein 1 (PD-1) antibodies (PD1) prolong recurrence-free survival in high-risk resected melanoma; however, approximately 25%-30% of patients recur within 1 year. This study describes the pattern of recurrence, management and outcomes of patients who recur with adjuvant PD1 therapy.Patients and methods: Consecutive patients from 16 centres who recurred having received adjuvant PD1 therapy for resected stage III/IV melanoma were studied. Recurrence characteristics, management and outcomes were examined; patients with mucosal melanoma were analysed separately.Results: Melanoma recurrence occurred in 147 (17%) of ∼850 patients treated with adjuvant PD1. In those with cutaneous melanoma (n = 136), median time to recurrence was 4.6 months (range 0.3-35.7); 104 (76%) recurred during (ON) adjuvant PD1 after a median 3.2 months and 32 (24%) following (OFF) treatment cessation after a median 12.5 months, including in 21 (15%) who ceased early for toxicity. Fifty-nine (43%) recurred with locoregional disease only and 77 (57%) with distant disease. Of those who recurred locally, 22/59 (37%) subsequently recurred distantly. Eighty-nine (65%) patients received systemic therapy after recurrence. Of those who recurred ON adjuvant PD1, none (0/6) responded to PD1 alone; 8/33 assessable patients (24%) responded to ipilimumab (alone or in combination with PD1) and 18/23 (78%) responded to BRAF/MEK inhibitors. Of those who recurred OFF adjuvant PD1, two out of five (40%) responded to PD1 monotherapy, two out of five (40%) responded to ipilimumab-based therapy and 9/10 (90%) responded to BRAF/MEK inhibitors.Conclusions: Most patients who recur early despite adjuvant PD1 develop distant metastases. In those who recur ON adjuvant PD1, there is minimal activity of further PD1 monotherapy, but ipilimumab (alone or in combination with PD1) and BRAF/MEK inhibitors have clinical utility. Retreatment with PD1 may have activity in select patients who recur OFF PD1.</p

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Cytomegalovirus and other herpesviruses infections in heart and bone marrow transplant recipients Infecções causadas por citomegalovírus e outros vírus do grupo herpes em transplantados cardíacos e de medula óssea

From January 1988 to January 1989 all the heart transplant and bone marrow recipients at the Instituto do Coração of the Hospital das Clínicas of the University of São Paulo Medical School were studied for the incidence and morbidity associated with herpesviruses infections after transplantation. Five bone marrow and 5 heart transplant recipients were followed for a mean of 4.2 months post-transplantation. All the patients were seropositive for cytomegalovirus (CMV) before admission and 80% experienced one or more recurrences during the observation period. Of the 12 episodes of CMV infection, that were identified in this study, 83% were accompanied by clinical or laboratory abnormalities. However, there was only one case of severe disease. The overall incidence of infection for herpes simplex (HSV) was 50%. Although most of HSV reactivations were oral or genital, one case of HSV hepatitis occurred. One of the 6 episodes of HSV infections that were treated with acyclovir showed an unsatisfactory response and was successfully managed with ganciclovir. All the individuals had anti-varicella zoster virus antibodies, but none of them developed infection. The study emphasizes the importance of active diagnostic surveillance of herpesvirus infections in transplant patients. Both CMV and HSV reactivations showed high incidence and important morbidity and thus, deserve prophylactic therapy.<br>De janeiro de 1988 a janeiro de 1989 todos os pacientes submetidos a transplante de coração ou de medula óssea no Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo foram estudados quanto à incidência e morbidade das infecções pós-transplante causadas por vírus do grupo herpes. Cinco recipientes de medula óssea e 5 transplantados cardíacos foram observados por um período médio de 4.2 meses após o transplante. Todos os pacientes tinham sorologia positiva para citomegalovírus (CMV) antes do transplante e 80% desenvolveram uma ou mais recorrências durante o período de observação. Dos 12 episódios de infecão por CMV detectados neste estudo, 83% foram acompanhados por alterações clínicas ou laboratoriais. Apenas um caso apresentou doença grave. A incidência de infecções causadas por vírus Herpes simplex (HSV), foi de 50%. Apesar da maioria das reativações do HSV fossem representadas por lesões orais ou genitais, houve também um caso de hepatite por HSV. Um dos 6 episódios de infecção, por HSV que foram tratados com aciclovir não respondeu ao tratamento. Posteriormente, o paciente se beneficiou com o uso de ganciclovir. Todos os indivíduos apresentavam antes do transplante anticorpos anti-vírus da varicela zoster. Porém, não houve nenhum caso de reativação. Este estudo realça a importância do controle diagnóstico ativo das infecções por herpes-vírus em pacientes transplantados. Tanto as infecções causadas por CMV como por HSV mostraram alta incidência e grande morbidade indicando a necessidade de quimioprofilaxia