A graded distribution of pinning centers (antidots) in superconducting MoGe thin films has been investigated by magnetization and magneto-optical imaging. The pinning landscape has maximum density at the border, decreasing progressively towards the center. At high temperatures and low fields, where this landscape mimics the vortex distribution predicted by the Bean model, an increase of the critical current is observed. At low temperatures and fields, the superconducting performance of the non-uniform sample is also improved due to suppression of thermomagnetic avalanches. These findings emphasize the relevance of non-uniform pinning landscapes, so far experimentally unexplored, on the enhancement of pinning efficiency.

Neurotrophins, such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), have been implicated in the generation and modulation of pain. To investigate whether alterations in neurotrophin levels can be detected in subjects suffering from nociceptive disorders, such as primary headaches, we determined the peripheral (platelet and plasma) levels of BDNF and NGF in patients suffering from migraine, with or without aura, or cluster headache (CH), in the interictal phase, and in healthy volunteers. All primary headaches patients studied showed significantly decreased platelet levels of BDNF (migraine vs. controls P<0.001; CH vs. controls P<0.01), while a selective reduction of platelet NGF was observed in migraine sufferers and not in CH patients compared with control subjects (migraine vs. controls P<0.001). These changes were not accompanied by significant modifications of neurotrophin plasma levels. Our findings show for the first time that changes in peripheral levels of neurotrophines (BDNF and NGF) occur in patients suffering from different types of primary headaches, suggesting a potential involvement of BDNF and NGF in the pathophysiology of these disorders, and raising the possibility that differences in peripheral neurotrophins may help to distinguish migraine biologically from CH.

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The morphology of abrupt bursts of magnetic flux into superconducting films with engineered periodic pinning centers (antidots) has been investigated. Guided flux avalanches of thermomagnetic origin develop a tree-like structure, with the main trunk perpendicular to the borders of the sample, while secondary branches follow well-defined directions determined by the geometrical details of the underlying periodic pinning landscape. Strikingly, we demonstrate that in a superconductor with relatively weak random pinning, the morphology of such flux avalanches can be fully controlled by proper combinations of lattice symmetry and antidot geometry. Moreover, the resulting flux patterns can be reproduced, to the finest details, by simulations based on a phenomenological thermomagnetic model. In turn, this model can be used to predict such complex structures and to estimate physical variables of more difficult experimental access, such as the local values of temperature and electric field.

Enhanced upper critical field, critical current density, and thermal activation energy in new ytterbium doped CeFeAsO0.9F0.1 superconductor J. Appl. Phys. 113, 043924 (2013) Temperature-and field-dependent critical currents in [(Bi,Pb)2Sr2Ca2Cu3Ox]0.07(La0.7Sr0.3MnO3)0.03 thick films grown on LaAlO3 substrates J. Appl. Phys. 113, 043916 (2013) Transport critical current measurement apparatus using liquid nitrogen cooled high-Tc superconducting magnet with variable temperature insert Rev. Sci. Instrum. 84, 015113 (2013) Additional information on Appl. Phys. Lett.

Objective: To evaluate the association between low birth weight and nutritional status at the end of the first year of life.Methods: This was a nested case-control study within a cohort. The study was carried out at maternity hospitals in four cities in the Zona da Mata Meridional in Pernambuco state, Brazil. Newborn infants were recruited during the first 24 hours of life. Their weights were measured at birth and at the end of the first year of life. Household visits were made twice weekly during the first year of life to collect data on breastfeeding and occurrence of diarrhea. In the case-control study, each case (child at nutritional risk) was a child with weight-for-age index < the 10th percentile (n = 117) and each control was a child with weight-for-age index > the 10th percentile (n = 411). Hierarchical logistic regression analysis was used to investigate risk factors for nutritional status at 12 months.Results: Low birth weight and living in a household with no latrine were significantly associated with nutritional risk at the end of the first year of life. Children born weighing 1,500 g to 2,499 g had 29 times (95% CI = 9.77-87.49) the chance of being at nutritional risk at 12 months of life than those whose birth weights had been > 3,500 g (p < 0.001). Children living in households without a flush toilet had three times (95% CI = 1.54-6.22) the chance of nutritional risk at 12 months of life in relation to those that had a latrine with a septic tank at home (p = 0.01).

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