Bruno Lima

Magnetite Colloidal Nanocrystals: A Facile Pathway To Prepare Mesoporous Hematite Thin Films for Photoelectrochemical Water Splitting

In this study, we demonstrate an alternative and promising way to produce hematite photoanodes with high performance and without the addition of doping or catalytic coating. In this approach, we processed hematite thin films using a colloidal dispersion of magnetite nanocrystals as the precursor. The photoelectrochemical characterization shows that the colloidal approach used to process an undoped hematite photoanode produced a high-performance electrode for water photooxidation with an onset potential as low as 0.8 V(RHE). This value is comparable to the best results reported in the literature for a hematite photoanode modified with catalytic materials. We demonstrate that pure hematite thin films reach 1.1 mA·cm(-2) at 1.23 V(RHE) with back-side illumination.

Estudo de polimorfismos genéticos do HLA (classes I e II) e do TNF-á em doentes com sarcoidose

Introduction: Several factors suggest a genetic predisposition to sarcoidosis, namely the recognition of race as a risk factor and the occurrence of familial clustering of cases. Several studies have reported an association of sarcoidosis and HLA class I and especially class II alleles in different populations. Aim: HLA class I, class II and TNF-α genotyping in a group of sarcoidosis patients and its relation with clinical presentation and outcome. Material and methods: A total of 104 sarcoidosis patients were included. Clinical presentation, functional, radiology, BAL findings and organ involvement were studied. HLA– A*, -B*, -C*, DRB1*, DQB1* and TNF-α were genotyped by molecular biology methods. DNA was extracted from peripheral blood and PCR-SSP and PCR-reverse hybridisation methods were used. Allele frequencies were compared with controls from the same region. The X2 test was used for discrete values and the Kruskal-Wallis test for continuous values. Results: When patients were compared with controls we noticed increased frequencies of B*08 (10.6% vs. 6.1%), O.R. = 1.8, C.I. = [1.1;3.1], p = 0.02; DRB1*12 (4.3% vs. 1.7%), O.R. = 2.63, C.I. = [1.1;6.1], p = 0.03. Patients with erythema nodosum have increased frequencies of the alleles DRB1*03 (28% vs. 9.3%), R.R. = 2.39, C.I. = [1.5;3.8], pc = 0.01 and DQB1*02 (38% vs. 18%), R.R. = 2.1, C.I. = [1.3;3.3], pc = 0.02. Allele DQB1*03 is decreased in patients with obstructive pattern R.R. = 0.53, C.I. = [0.3;0.9], pc = 0.05. Allele DRB1*15 is related to restrictive pattern and reduced diffusion capacity (21.1% vs. 6.6%), R.R. = 2.46, C.I. = [1.35;4.48], p = 0.01 and (18.1% vs. 3.8%), R.R. = 1.87, pc = 0.05 respectively. The TNF-α A/A (high) genotype is significantly associated with erythema nodosum (p = 0.04). Conclusions: These data add support to the genetic association of HLA class I and II with sarcoidosis in terms of susceptibility, type of presentation, severity and outcome. Moreover as previously described in other populations, the TNF-α A/A (high) genotype has a significant association with erythema nodosum. Rev Port Pneumol 2008; XIV (6): 727-746