Coupled electric and magnetic dipole formulation for planar arrays of dipolar particles: metasurfaces with various electric and/or magnetic meta-atoms per unit cell

The optical properties of infinite planar array of scattering particles, metasurfaces and metagratings, are attracting special attention lately for their rich phenomenology, including both plasmonic and high-refractive-index dielectric meta-atoms with a variety of electric and magnetic resonant responses. Herein we derive a coupled electric and magnetic dipole (CEMD) analytical formulation to describe the reflection and transmission of such periodic arrays, including specular and diffractive orders, valid in the spectral regimes where only dipolar multipoles are needed. Electric and/or magnetic dipoles with all three orientations arising in turn from a single or various meta-atoms per unit cell are considered. The 2D lattice Green function is rewritten in terms of a 1D (chain) version that fully converges and can be easily calculated. Modes emerging as poles of such lattice Green function can be extracted. This formulation can be applied to investigate a wealth of plasmonic, all-dielectric, and hybrid metasurfaces/metagratings of interest throughout the electromagnetic spectrum.Comment: 8 pages, 4 figure

Cardiac Arrest in the Pediatric Population

Apresenta-se o caso clínico de uma criança de 10 anos com paragem cardíaca em repouso que foi reanimada, com sucesso. A investigação etiológica do acidente mostrou uma Cardiomiopatia Hipertrófica (CMH). Foi colocado um Cardiodesfibrilhador Implantável (CDI) para profilaxia secundária da Morte Súbita (MS). A Morte Súbita em idade pediátrica é uma situação rara, de muito mau prognóstico (sobrevida sem sequelas inferior a 5%) e com um impacto social significativo. A Cardiomiopatia Hipertrófica é uma causa conhecida de Morte Súbita, com possibilidade de prevenção. O caso apresentado serve para levantar questões sobre a necessidade e forma de estratégias para prevenir a MS de etiologica cardíaca em idade pediátrica

Generation and remote detection of THz sound using semiconductor superlattices

The authors introduce a novel approach to study the propagation of high frequency acoustic phonons in which the generation and detection involves two spatially separated superlattices $\sim 1 {\rm \mu m}$ apart. Propagating modes of frequencies up to $\sim 1 {\rm THz}$ escape from the superlattice where they are generated and reach the second superlattice where they are detected. The measured frequency spectrum reveals finite size effects, which can be accounted for by a continuum elastic model.Comment: Submitted to Applied Physics Letter

Vascular resection for intrahepatic cholangiocarcinoma: Current considerations

Intrahepatic cholangiocarcinoma (iCCA) accounts for approximately 10% of all primary liver cancers. Surgery is the only potentially curative treatment, even in cases of macrovascular invasion. Since resection offers the only curative chance, even extended liver resection combined with complex vascular or biliary reconstruction of the surrounding organs seems justified to achieve complete tumour removal. In selected cases, the major vascular resection is the only change to try getting the cure. The best results are achieved by the referral centre with a wide experience in complex liver surgery, such as ALPPS procedure, IVC resection, and ante-situ and ex-situ resections. However, despite aggressive surgery, tumour recurrence occurs frequently and long-term oncological results are very poor. This suggests that significant progress in prognosis cannot be expected by surgery alone. Instead, multimodal treatment including neoadjuvant chemotherapy, radiotherapy, and subsequent adjuvant treatment for iCCA seem to be necessary to improve results. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Insect pollinators of Jasminocereus thouarsii, an endemic cactus of the Galapagos Islands

Jasminocereus is a columnar cactus endemic to the Galapagos Islands, and is distributed mainly in the lowland arid zones. Its only species, J. thouarsii, has several varieties on different islands. Observations of the variety J. thouarsii var. delicatus on Santa Cruz Island suggested limited recruitment. We therefore studied its floral biology, pollination requirements and seed germination to determine whether recruitment might be limited by seed production or seed quality. Flowers opened in the early morning, from 5h00 to 10h00. No seed was produced by flowers isolated in pollination bags. Pollination was allogamous, mostly brought about by the endemic Xylocopa darwini (Hymenoptera: Apidae), followed by the introduced Acrosticta apicalis (Diptera) and endemic Camponotus planus (Hymenoptera: Formicidae). Seeds germinated well, with the highest germination rate obtained from seeds that were soaked before planting

Subaortic Stenosis Following Anatomic Correction for Transposition of the Great Arteries

Os autores descrevem o caso clínico de uma criança do sexo masculino, com 12 anos de idade, com diagnóstico pós-natal de transposição das grandes artérias com comunicação interventricular, submetida a switch arterial e encerramento da comunicação interventricular. Durante o seguimento pós-operatório detectou-se um obstáculo entre o ventrículo esquerdo e a aorta ascendente que foi, inicialmente, de grau ligeiro. No último ano começou a referir sintomatologia (cansaço para esforços moderados). Na avaliação efectuada detectou-se uma estenose aórtica subvalvular grave, tendo o doente sido submetido a tratamento cirúrgico, com bom resultado. A estenose aórtica subvalvular é uma complicação rara, que tem sido descrita em estudos de follow-up de switch arterial, sobretudo nas situações em que o defeito primário é a transposição das grandes artérias com comunicação interventricular