16,242 research outputs found
Association of radio polar cap brightening with bright patches and coronal holes
Radio-bright regions near the solar poles are frequently observed in Nobeyama
Radioheliograph (NoRH) maps at 17 GHz, and often in association with coronal
holes. However, the origin of these polar brightening has not been established
yet. We propose that small magnetic loops are the source of these bright
patches, and present modeling results that reproduce the main observational
characteristics of the polar brightening within coronal holes at 17 GHz. The
simulations were carried out by calculating the radio emission of the small
loops, with several temperature and density profiles, within a 2D coronal hole
atmospheric model. If located at high latitudes, the size of the simulated
bright patches are much smaller than the beam size and they present the
instrument beam size when observed. The larger bright patches can be generated
by a great number of small magnetic loops unresolved by the NoRH beam. Loop
models that reproduce bright patches contain denser and hotter plasma near the
upper chromosphere and lower corona. On the other hand, loops with increased
plasma density and temperature only in the corona do not contribute to the
emission at 17 GHz. This could explain the absence of a one-to-one association
between the 17 GHz bright patches and those observed in extreme ultraviolet.
Moreover, the emission arising from small magnetic loops located close to the
limb may merge with the usual limb brightening profile, increasing its
brightness temperature and width.Comment: 8 pages, 6 figures, 1 table. Accepted for publication in The
Astrophysical Journa
Neoadjuvant use of Imiquimod Before Surgery in Extramammary Paget’s Disease
A doença de Paget extramamária (DPEM) é uma neoplasia maligna cutânea, rara, observada principalmente em mulheres caucasianas pós-menopausa. A cirurgia é o tratamento mais comum. No entanto, no que diz respeito à DPEM vulvar, o seu tratamento cirúrgico passa frequentemente por cirurgia radical, que pode ser mutilante e levar à perda de feminilidade. Recentes avanços terapêuticos têm incluÃdo abordagem médica e multimodal médico-cirúrgico, permitindo uma maior preservação da anatomia genital e subsequente diminuição da morbilidade. Neste sentido, imiquimod tem sido utilizado, off-label, como monoterapia ou terapêutica adjuvante na DPEM.Relatamos o caso de uma mulher com DPEM extenso na área anogenital submetida a resseção cirúrgica complementada com reconstrução plástica e precedida de tratamento médico com imiquimod. O imiquimod neoadjuvante permitiu uma citorredução significativa da área tumoral, minimizando a radicalidade cirúrgica, mantendo a função local e a morfologia.Extramammary Paget's disease (EMPD) is a distinct form of a rare malignant skin neoplasm, primarily seen in postmenopausal Caucasian women. Surgery is the most common treatment. However, concerning vulvar EMPD, radical surgery can be mutilating and leads to loss of femininity. Recent therapeutic development has included medical and medical-surgical approaches, allowing better preservation of genital anatomy with subsequent reduced morbidity. Accordingly, off-label use of imiquimod has been reported as a monotherapy or adjuvant therapy in EMPD.We report the case of a woman with extensive EMPD in the anogenital area, submitted to surgical resection complemented with plastic reconstruction and preceded by imiquimod medical treatment. Neoadjuvant imiquimod induced a significant cytoreduction of the tumor area, minimizing surgical radicality and maintaining local function and morpholog
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