Magnetic exchange mechanism for electronic gap opening in graphene

We show within a local self-consistent mean-field treatment that a random distribution of magnetic adatoms can open a robust gap in the electronic spectrum of graphene. The electronic gap results from the interplay between the nature of the graphene sublattice structure and the exchange interaction between adatoms.The size of the gap depends on the strength of the exchange interaction between carriers and localized spins and can be controlled by both temperature and external magnetic field. Furthermore, we show that an external magnetic field creates an imbalance of spin-up and spin-down carriers at the Fermi level, making doped graphene suitable for spin injection and other spintronic applications.Comment: 5 pages, 5 figure

Phenomenological study of the electronic transport coefficients of graphene

Using a semi-classical approach and input from experiments on the conductivity of graphene, we determine the electronic density dependence of the electronic transport coefficients -- conductivity, thermal conductivity and thermopower -- of doped graphene. Also the electronic density dependence of the optical conductivity is obtained. Finally we show that the classical Hall effect (low field) in graphene has the same form as for the independent electron case, characterized by a parabolic dispersion, as long as the relaxation time is proportional to the momentum.Comment: 4 pages, 1 figur

Electron waves in chemically substituted graphene

We present exact analytical and numerical results for the electronic spectra and the Friedel oscillations around a substitutional impurity atom in a graphene lattice. A chemical dopant in graphene introduces changes in the on-site potential as well as in the hopping amplitude. We employ a T-matrix formalism and find that disorder in the hopping introduces additional interference terms around the impurity that can be understood in terms of bound, semi-bound, and unbound processes for the Dirac electrons. These interference effects can be detected by scanning tunneling microscopy.Comment: 4 pages, 7 figure

Subcutaneous immunotherapy with aeroallergens-evaluation of adherence in real life

Introduction. Adherence in allergen immunotherapy is crucial for its efficacy. At least 3 years of treatment are recommended for achieving a long-term modifying effect. Objectives. To assess patient’s adherence and to identify determinant factors for allergen subcutaneous immunotherapy (SCIT) suspension in patients with respiratory allergy. Methods. Retrospective analysis of the medical record of patients submitted to SCIT between January 2013 and December 2016 in our Department. Results. 323 patients were included: 52% female; mean age 30 ± 13 years; average treatment time 19 ± 13 months. 52 patients (16%) stopped SCIT: 54% female; mean age 30 ± 9 years; average treatment time 12 ± 6 months; 67% dropped the treatment during the 1st year, 27% in the 2nd and 6% during the 3rd year of treatment. Adherence rate determined was 77%. The most frequent reasons for withdrawal were due to economic reasons (47.9%), followed by patients’ perception of no clinical improvement (23%) and change to sublingual immunotherapy (11.6%). Conclusions. Adherence rate in our study was 77%. Economic reasons were the main cause of abandonment in the first year, while the perception of non-improvement was the main reason for abandonment in subsequent years. Adequate information on SCIT prescribing and rigorous monitoring of patients during the treatment can improve adherence.info:eu-repo/semantics/publishedVersio

A new method for testing antimicrobial activity of filamentous fungi

Tbls work was supporled by a FCT projecl (PTDC/AGR-AAM/099556/2008)

Portuguese consensus document statement in diagnostic and management of atypical hemolytic uremic syndrome

Among thrombotic microangiopathies (TMA), the hemolytic uremic syndrome associated with dysregulation of the alternative complement pathway (aHUS) is one of the most challenging diseases a nephrologist can face. By the end of the XXth century, the complement’s role was unraveled with the discovery that mutations in the factor H coding gene were responsible for aHUS. But it was the acknowledgment that pharmacological C5-9 blockage provided a cure for aHUS that fostered the interest of the nephrology community in the genetics, pathophysiology and therapeutics of, not only of aHUS, but TMA in general. The molecular genetics of aHUS is technically demanding and, as such, in Portugal (alike many other European countries) a single laboratory emerged as a national reference center. The fact that all samples are evaluated in a single center provides a unique opportunity for data collection and a forum for discussion for all those interested in the field: immunologists, molecular geneticists, pathologists and nephrologists. The current consensus document emerged from such a discussion forum and was sponsored by the Portuguese Society of Nephrology. The goal is more to portray the Portuguese picture regarding the diagnostic approach and therapeutic options than to extensively review the state of the art of the subject. The accompanying documents that are published as supplementary data are in line with that goal. They range from the informed consent and clinical form to be sent together with the biological samples for genetic testing, to the appendix regarding the actual sampling and storing conditions. The document is also intended to set an example for future documents and independente discussion forums on other kidney diseases for which emerging diagnostic and/or therapeutic strategies are reaching clinical practice.info:eu-repo/semantics/publishedVersio

Cultivares e híbridos de repolho para produção orgânica no verão do Distrito Federal.

Este trabalho teve como objetivo avaliar o desempenho agronômico de algumas cultivares e hibridos de repolho em sistema orgânico nas condições de verão do Distrito Federal.Trabalho apresentado no 4 Seminário de Agroecologia do Distrito Federal e Entorno, Brasília, DF