Properties of nanoparticles prepared from NdFeB-based compound for magnetic hyperthermia application

Nanoparticles were prepared from a NdFeB-based alloy using the hydrogen decrepitation process together with high-energy ball milling and tested as heating agent for magnetic hyperthermia. In the milling time range evaluated (up to 10 h), the magnetic moment per mass at H = 1.59 MA m(-1) is superior than 70 A m(2) kg(-1); however, the intrinsic coercivity might be inferior than 20 kA m(-1). The material presents both ferromagnetic and superparamagnetic particles constituted by a mixture of phases due to the incomplete disproportionation reaction of Nd2Fe14BHx during milling. Solutions prepared with deionized water and magnetic particles exposed to an AC magnetic field (H-max similar to 3.7 kA m(-1) and f = 228 kHz) exhibited 26 K <= Delta T-max <= 44 K with a maximum estimated specific absorption rate (SAR) of 225 W kg(-1). For the pure magnetic material milled for the longest period of time (10 h), the SAR was estimated as similar to 2500 W kg(-1). In vitro tests indicated that the powders have acceptable cytotoxicity over a wide range of concentration (0.1-100 mu g ml(-1)) due to the coating applied during milling.

Effects of the Compaction Pressure on the Magnetic Properties of a Sintered Fe-Based Alloy

The structural and magnetic properties of a Fe-based alloy before and after sintering have been analyzed. X ray diffraction measurements confirm the deformation of the magnetic particles in the compacted samples. After sintering, hysteresis energy dissipation, remanence and intrinsic coercivity differ by less than 10% as porosity changes from 15 to 7%.

Vulvo-cervico-vaginal manifestations and evaluation of Papanicolaou smears in pemphigus vulgaris and pemphigus foliaceus

Background: Vulvo-cervico-vaginal involvement has rarely been reported in pemphigus vulgaris (PV) and has not been reported in pemphigus foliaceus (PF). Objectives: We sought to evaluate genital lesions and Papanicolaou (Pap) smears in female patients with PV and PF. Methods: This prospective study includes all consecutive cases of female patients with PV and PF seen from May 2009 to February 2010. Gynecologic examination was performed and Pap smears were collected for cytologic analysis from each patient. Results: A total of 56 patients were given a diagnosis of pemphigus (41 PV and 15 PF). Genital involvement was observed in 9 patients with PV (22%) and the vulva was the most common genital site of involvement. Of these 9 patients, 8 presented with active skin/mucous lesions. Four of 15 patients with PF had genital lesions and vulva was the exclusive site of involvement. Three of 4 patients with PF and genital involvement also showed active cutaneous lesions. Six of 56 patients (5 PV and 1 PF) presented with atypical squamous cells of undetermined significance in Pap smear analysis. Upon further pathologic review, acantholytic cells were seen, confirming the diagnosis of pemphigus. Limitations: A small number of PF cases were studied. Conclusions: Vulvar lesions were the second most frequent site of mucous membrane PV. Herein we report the first case to our knowledge of symptomatic genital lesions in a patient with PF. Moreover, acantholytic cells in Pap smears were found in a patient with PF who was in complete remission off therapy with no clinical genital lesions and no circulating anti-desmoglein-1 and anti-desmoglein-3 autoantibodies. Gynecologic evaluation in patients with pemphigus, including a careful evaluation of Pap smears, should be recommended. (J Am Acad Dermatol 2012;67:409-16.)

The effects of the pressing step on the microstructure and aging of NdFeB bonded magnets

The effects of the compaction step on the (micro)structural features and aging behavior of polymer coated NdFeB-based bonded magnets is reported. Due to the fracture of the material during pressing, it is estimated an increase of at least 14% in the particles' area which is not coated. Such uncoated surfaces, when exposed to the environment, reduce the magnetic performance of the magnets aged/cured in air by 19% in the conditions evaluated in this investigation. Furthermore, XRD results interpreted by Rietveld analyses show a lattice parameter change in the tetragonal structure of the hard magnetic phase after pressing. Such change varies as a function of the height of the compacted part and it is ascribed to macro-elastic stress arising from the pressure distribution in the magnet. An aging/curing step during 24 h is able to relief such macro-elastic stress. (C) 2012 Elsevier B.V. All rights reserved.

A difícil arte de "deslizar sobre o mundo" ou Montaigne, um político discreto ("De poupar a própria vontade" - III, 10)

De 1581 a 1585, Montaigne foi prefeito de Bordeaux. Foi acusado por detratores de não se ter aplicado o bastante e de não ter feito nada de marcante durante seus dois mandatos. Ao responder às acusações no ensaio "De poupar a própria vontade" (III, 10), o autor encontra a ocasião para uma crítica das paixões em geral e, em particular, das que pertencem ao contexto político. Isto porque ele visava, com sua aparente falta de aplicação aos deveres de prefeito, evitar a paixão que tantas vezes se oculta por trás do engajamento - a ambição, desejo de honras, glória, renome. Sobretudo, esperava evitar um duplo perigo, ao mesmo tempo ético e político: comprometer a própria liberdade numa busca servil da glória e subordinar o bem coletivo ao interesse pessoal. No presente estudo, procuraremos reconstituir a trama argumentativa do ensaio em questão, acompanhando de perto os argumentos que sustentam a crítica montaigniana das paixões, bem como a terapia muito particular a que o ensaísta as submete, a qual lhe permite fazer do episódio da Mairie de Bordeaux um modelo de conciliação entre o cuidado de si e o cumprimento dos deveres políticos.