Small-scale solar magnetic fields

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

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

Social Aspects of Kidney Donation in Tunisia: A Study of 189 Living Related Donors

No Abstract

Mélanome anorectal primitif

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

Structural, magnetic and magnetocaloric properties of Li-substituted La0.8K0.2-xLixMnO3 perovskite manganites

International audienceIn this study we report the effect of lithium substitution on the structural, magnetic and magnetocaloric properties of La0.8K0.2-xLixMnO3 (0 ≤ x ≤ 0.075) samples synthesized by the sol–gel technique at low temperature. The investigated compounds crystallize in a rhombohedral system with R3c space group. The thermal variation of the magnetization under an applied magnetic field of 0.05 T showed that all our compounds exhibited aparamagnetic to ferromagnetic transition with decreasing temperature. With increasing lithium content, the Curie temperature TC, decreases from 287.4 K for x = 0 to 172.6 K for x = 0.075. The maximum of the magnetic entropy change, ΔSMaxM , is found to be 3.19, 3.51, 2.39 and 2.24 J kg 1 K 1 in a magnetic field change of 5 T for x = 0, 0.025, 0.05 and 0.075 respectively. The La0.8K0.175Li0.025MnO3 sample displays a higher maximum relativecooling power value of 320.5 J kg 1, equal to 78 % of that of gadolinium. Technically, this large value associated to a TC of 270 K makes the present sample very promising for magnetic refrigeration technology below room temperature

RSC Adv.

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