31 research outputs found

    Small-scale solar magnetic fields

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    As we resolve ever smaller structures in the solar atmosphere, it has become clear that magnetism is an important component of those small structures. Small-scale magnetism holds the key to many poorly understood facets of solar magnetism on all scales, such as the existence of a local dynamo, chromospheric heating, and flux emergence, to name a few. Here, we review our knowledge of small-scale photospheric fields, with particular emphasis on quiet-sun field, and discuss the implications of several results obtained recently using new instruments, as well as future prospects in this field of research.Comment: 43 pages, 18 figure

    Hepatic primary neuroendocrine carcinoma: About a new case

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    We report a new case of Primary hepatic neuroendocrine carcinoma admitted in our hospital and revealed in 53 years man by epigastric pain and flush syndrom. A liver biopsy with immunohistochemical study confirmed the original location of a neuroendocrine carcinoma. After 12 cures of Chemotherapy and a follow up of 12 months, the patient is still in complete remission

    Mélanome anorectal primitif

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    Nous proposons une étude rétrospective réalisée au sein du département de gastro-entérologie et d'Oncologie du CHU Casablanca colligeant tous les cas des mélanomes ano-rectaux primitifs, sur une période de 15 ans (du 1997 au 2012). Notre série comportait 14 patients, 8 hommes et 6 femmes avec une moyenne d'âge de 60,5 ans. Les signes cliniques étaient dominés par les rectorragies et le syndrome rectal (plus de 80% des malades). L'aspect tumoral noirâtre à été noté chez la moitié des malades. L'examen endoscopique a révélé une prédominance des lésions ulcéro-bourgeonnantes. Dans 5 cas la tumeur était plus haut située entre 5 à 8 cm de la marge anale. Le bilan d'extension avait décelé des métastases ganglionnaires, osseuses ou viscérales chez 7 malades. Un traitement chirurgical a été pratiqué chez 50% des malades (7 cas). Il a consisté en une exérèse locale isolée (2 cas) ou associée à une radiothérapie (2 cas) et une amputation abdomino-périnéale dans 3 cas. Quatre malades ont reçu une chimiothérapie et/ou radiothérapie palliative et dans deux cas on s'est contenté d'un traitement symptomatique. L'évolution a été marquée par une récidive chez les 2 patients traités par exérèse locale, dont un a été bénéficié d'une amputation abdomino-pelvienne de rattrapage et un des trois patients traités par chirurgie radicale. Deux patients sont en rémission complète après 36 mois de recul

    RSC Adv.

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    Current biomedical imaging techniques are vital for the diagnosis of various diseases. They are related to the development of multimodal probes encompassing all the functionalities required for comprehensive imaging. In this context, we applied a simple and reproducible wet synthesis route to produce such probes. This method allowed us to prepare about 100 nm sized lanthanide-doped yttrium fluoride nanoparticles β-NaY0.8[Yb0.18Er0.02]F4, coated with about 10 nm sized iron oxide γ-Fe2O3 nanocrystals. By this way, the built granular hetero-nanostructures combine desirable up-converting photoluminescence (the core) and superparamagnetic properties (the satellites), enabling dual optical and magnetic resonance imaging applications. Through citrate ligand grafting, the designed core–satellite particles formed stable aqueous colloids, which are valuable for biomedical applications. Optical spectroscopy and confocal microscopy revealed their capability for sustained visible light emission (predominantly green) upon near-infrared excitation (980 nm). Additionally, based on XTT assays, when incubated for 24 hours with mammalian healthy or cancer cells, even at doses as high as 0.1 mg mL−1 (milligrams of particles), they did not induce significant cytotoxicity. The measured body temperature magnetization of the engineered nanoconstructs was found to be about 10 emu g−1 (grams of particles) at 1.5 T, which is high enough to use them as positive or negative contrast magnetic resonance agents in the clinic, as confirmed by relaxometry measurements in Milli-Q water. This result underscores their promising biomedical utility as bimodal probes for optical and magnetic imaging

    Surveillance of dengue fever virus: A review of epidemiological models and early warning systems

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    Dengue fever is one of the world’s most important vector-borne diseases. The transmission area of this disease continues to expand due to many factors including urban sprawl, increased travel and global warming. Current preventative techniques are primarily based on controlling mosquito vectors as other prophylactic measures, such as a tetravalent vaccine are unlikely to be available in the foreseeable future. However, the continually increasing dengue incidence suggests that this strategy alone is not sufficient. Epidemiological models attempt to predict future outbreaks using information on the risk factors of the disease. Through a systematic literature review, this paper aims at analyzing the different modeling methods and their outputs in terms of accurately predicting disease outbreaks. We found that many previous studies have not sufficiently accounted for the spatio-temporal features of the disease in the modeling process. Yet with advances in technology, the ability to incorporate such information as well as the socio-environmental aspect allowed for its use as an early warning system, albeit limited geographically to a local scale
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