Sequential anatectic processes in Mindelo Migmatite Complex (NW Portugal)

O Complexo Migmatítico de Mindelo aflora na orla litoral a norte do Porto sendo composto por um conjunto de litologias diversas incluindo rochas metassedimentares, migmatíticas,graníticas e veios pegmatíticos. As relações de campo, petrografia, geoquímica e assinatura isotópica das diversas litologias permitem deduzir a sequência de processos anatéticos que resultaram na heterogeneidade litológica presente. A fusão terá ocorrido em diferentes níveis estruturais e consequentemente em condições de pressão e temperatura distintos,resultando em rochas com características específicas: i) a níveis pouco profundos (< 3,5 Kbar)geram-se metatexitos e leucogranitos por migração de leucossomas. Os primeiros melts resultam essencialmente da fusão de quartzo e plagioclase por fusão húmida seguidos de reacções de fusão incongruente da biotite; (ii) a nível ligeiramente mais profundo a taxa de fusão é superior, o que leva à formação de diatexitos que, sendo menos densos do que a rocha encaixante, intruem os metatexitos; (iii) em níveis ainda mais profundos (~5 Kbar), a composição da rocha, conjuntamente com temperatura e pressão mais elevadas permitem a fusão da moscovite gerando melts típicos dos granitos de duas micas. Este material ascende na crusta e incorpora abundantes xenólitos formando um corpo granítico muito heterogéneo. Numa fase mais tardia ocorrem processos de metassomatismo potássico com feldspatização, na dependência de circulação de fluidos estruturalmente controlada, em migmatitos e em granitoides. Posteriormente ocorre turmalinização e moscovitização de alguns granitoides e instalação de veios aplitopegmatíticos.Mindelo Migmatitic Complex outcrops in the coastal-zone,north of Porto. This complex consists on a set of diverse lithologies including metasedimentary, migmatitic and granitic rocks, and pegmatite veins. Field relationships, petrography, geochemistry and isotopic signature of these lithologies allow inferring the sequence of anatectic processes that are responsible for the lithological heterogeneity. The melting occurred at different structural levels, and thus at different pressure and temperature conditions, generating rocks with specific characteristics: i) in shallow levels (<3.5 Kbar)metatexites are produced essentially by water-saturated melting followed by water-undersaturated biotite melting. Leucogranites resulted from migration of leucosomes; (ii ) in slightly deeper levels the melting rate is higher which leads to the formation of diatexites that intruded metatexites; (iii) in even deeper levels (~ 5 Kbar) higher pressure and temperature permit the melting of muscovite producing a large amount of typical two-mica granite melts. This material rises in the crust and incorporates abundant xenoliths forming a very heterogeneous granitic body. In subsolidus conditions, structurally controlled metasomatic processes lead to feldspatization of migmatites and granitoids. Later, installation of aplite-pegmatites and local tourmalinization previously formed granitoids took place

Complexo Migmatítico de Mindelo (NW de Portugal). Anatexia e relações petrogenéticas

Na orla litoral do norte de Portugal aflora uma faixa referida cartograficamente como “Complexo Granito-Migmatítico” inserida na formação Complexo Xisto-Grauváquico (CXG) [1]. Nesta faixa afloram litologias diversas, nomeadamente: i) rochas metassedimentares; ii) rochas migmatíticas; e, iii) rochas graníticas. O paleossoma metassedimentar apresenta foliação e bandado composicional marcado por bandas ricas em biotite, estaurolite e almandina e bandas ricas em quartzo e oligóclase(An12-19). As rochas migmatíticas dividem-se em quatro tipos distintos: i) metatexitos mosqueados; ii) metatexitos bandados; iii) diatexitos; e iv) resisters calcossilicatados. Os metatexitos mosqueados caracterizam-se pela ocorrência de neossoma in situ inserido numa matriz idêntica ao paleossoma. Este define-se por pequenas manchas constituídas por quartzo, plagióclase e cordierite circunscritas por selvedge de biotite. Os metatexitos bandados apresentam alternância entre melanossoma com biotite, silimanite, cordierite e rara almandina e leucossoma quartzofeldspático. Os diatexitos são rochas de composição essencialmente granítica de grão médio a grosseiro contendo remanescências de material metassedimentar (schlieren) constituídos por alinhamentos de biotite, silimanite, cordierite e rara almandina. O feldspato potássico é geralmente anédrico, substitui a plagioclase, e contém inclusões de todos minerais paragenéticos. A biotite tem bordos arredondados ou simpletíticos em associação com cordierite subédrica. Os resisters são rochas que pela sua constituição mineralógica não sofreram fusão parcial. Estão inseridos nos migmatitos e são constituídos por metagrauvaques cálcicos com textura granoblástica. Apresentam-se em nódulos elipsoidais, zonados, com espessura e comprimento centimétricos. O zonamento concêntrico destas rochas apresenta um núcleo mais rico em Ca, com diópsido, anortite(An82-92), grossulária(Grs70-90) e quartzo passando a um bordo menos rico em Ca composto por hornblenda, anortite, granada(Grs36-46) e quartzo. Estes núcleos calcossilicatados estão inseridos em camadas tabulares de metagrauvaque com quartzo, plagioclase(An36-44), biotite dispersa e rara almandina. Nas zonas mais ricas em Ca, no núcleo dos nódulos os metagrauvaques permanecem inalterados mas nas zonas exteriores mais pobres em Ca fundem parcialmente resultando um metatexito relativamente rico em Ca e Na. As rochas graníticas apresentam variação textural desde grão fino a médio. Têm mineralogia típica de granitos de duas micas, por vezes com raros alinhamentos de biotite e silimanite. Contêm xenólitos de metatexito e formam diques discordantes com o encaixante. Geoquimicamente os metatexitos pelíticos apresentam teores em elementos maiores , traço e padrão de terras raras similares aos xistos estaurolíticos e ao NIBAS [2]. Os nódulos calcossilicatados apresentam enriquecimento em Ca e Mn (Ca>9% e Mn>0,18) no núcleo com empobrecimento gradual para o exterior . Os granitos são do tipo S, peraluminosos, alcalino-cálcicos, medianamente diferenciados. Os diatexitos são calco-alcalinos e menos diferenciados do que os granitos. Em todas as litologias, a variação nos teores em “HSFE” (TR, Zr, Hf, Y) está positivamente relacionada com o teor em Fe2O3(t)+MgO. As variações na composição em elementos traço nas litologias referidas serão consequência da variabilidade na incorporação de minerais acessórios a partir do protólito, maioritariamente associados à biotite, condicionada pelas diferenças na composição mineralógica do mesmo e do grau de equilíbrio com o melt.. A assinatura isotópica de todas as litologias é crustal, com εSr330 > 121 e εNd < 0. Relativamente ao εNd330 distinguem-se dois grupos: um grupo que inclui xistos estaurolíticos, migmatitos mosqueados, diatexitos e granitos com valores entre -2,05 e -5,08 e o grupo dos resisters com valores entre -8,12 e -9,30. Os migmatitos bandados apresentam valores que variam entre estes dois grupos distintos. Estes valores permitem considerar uma relação genética entre os granitos, os migmatitos e os xistos estaurolíticos e uma fonte distinta para os metagrauvaques. Os aspetos litológicos, petrográficos e geoquímicos sugerem três etapas de anatexia/cristalização: i) um primeiro melt resultante da fusão incongruente de biotite, produz minerais anidros (cordierite + plagioclase + quartzo); ii) circulação de fluidos ricos em K por cristalização e diferenciação de melts de níveis mais profundos, onde a taxa de fusão é superior, e que atingindo os migmatitos superiores levam à cristalização de ortoclase e à feldspatização da plagioclase. Esses fluidos, com circulação condicionada estruturalmente, não atingiram todo o complexo migmatítico uma vez que há metatexitos e diatexitos sem feldspato; iii) Nos níveis de maior taxa de fusão há formação de magmas graníticos de tipo S. Estes são menos densos do que as rochas encaixantes o que promove a sua ascensão e instalação, gerando granitos de duas micas, que incorporam xenólitos de migmatitos (metatexíticos e diatexíticos)

Alcohol consumption among patients with hepatitis B infection in northern Portugal considering gender and hepatitis B virus genotype differences

Alcohol. 2010 Mar;44(2):149-56. Epub 2010 Jan 29. Alcohol consumption among patients with hepatitis B infection in northern Portugal considering gender and hepatitis B virus genotype differences. Mota A, Guedes F, Areias J, Pinho L, Cardoso MF. SourceInstituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Portugal. Abstract Alcohol abuse is an important public health problem. In Portugal with a population of 10 millions of inhabitants, there are around 10% of alcoholics or excessive alcohol drinkers and 1% of chronically infected patients with hepatitis B virus (HBV). To examine the characteristics of patients with higher levels of alcohol consumption and to investigate the association between alcohol consumption and liver damage a total of 298 chronically infected individuals, with HBV genotyped and submitted to liver biopsy, were classified with Child's grading and separated by habits of alcohol intake, less and greater than 20g/day. No significant differences were observed about genotype but genotypes A and D were predominant in both of them. A higher percentage of males (P<.001) were observed in the group with alcohol intake above 20g/day, as well a lower proportion of patients with HBeAg negativity (P< or =.035). In this group, biochemistry parameters, such as alanine aminotransferase (P=.006), aspartate aminotransferase (P=.001), gamma-glutamyl transferase (P<.001) were elevated in a significantly higher proportion than in the other group. The analysis of hematological parameters showed significantly lower values of platelets (P=.042) and mean corpuscular volume (P<.001) and significantly higher values of prothrombin time (P<.001) in the group with higher levels of alcohol consumption. The characteristics of biopsy (P<.001) and Child-Phug's classification (P=.002) revealed more severe results in this group. Logistic regression showed a positive association between liver damage and alcohol intake, increasing with age. In female patients, a strong positive association between alcohol intake and liver damage was also found (odds ratio: 9.379; 95% confidence interval: 0.859-468.422; P = .037); however, the most severe cases were only observed in women older than 45 years. In patients with HBV infection, alcohol is associated with a more severe liver disease. No evidence was found concerning association with HBV genotype. 2010 Elsevier Inc. All rights reserved

Epidemiological study of genotypes of hepatitis B virus in northerm Portugal

ed Virol. 2009 Jul;81(7):1170-6. Epidemiological study of genotypes of hepatitis B virus in northern Portugal. Mota A, Guedes F, Areias J, Pinho L, Cardoso MF. SourceInstituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal. Abstract While the overall prevalence of hepatitis B virus (HBV) infection in Portugal is around 1%, there are no published studies examining HBV genotypes in this country. This study aimed to survey HBV genotypes in the northern Portugal and to examine the possible associations between genotypes and gender, viral transmission routes, viral markers, viral load, and biochemical tests of liver function. The study sample consists of 340 patients with HBV infection of whom 42.9% were women. Tests were carried out for HBV genotypes and biochemical liver function while demographic information, including alcohol intake, was obtained from the patient files. The results indicate the predominance of genotype D (60.3%) and genotype A (31.5%). Intrafamilial transmission was predominant in female patients, while males were infected in equal proportions by perinatal, sexual, and intrafamilial transmission. Absence of HBeAg was found in a significantly smaller proportion of female patients with genotype D as compared to A (56.6% vs. 82.1%, P = 0.028). High viral load was associated significantly and independently with genotype D and HBeAg. Both alanine and aspartate aminotransferases (ALT and AST) were associated with gender and HBeAg. Thus, genotypes A and D were found to be the most prevalent in the north of Portugal. Patients infected with genotype D had higher levels of HBV DNA. HBeAg was associated with genotype D, viral load, and ALT and AST

New synthetic compounds as inhibitors of mycotoxin synthesis

Ochratoxin A (OTA) is a mycotoxin produced by some Aspergillus and Penicillium species which is often detected in beer, cereals, coffee, feeds, figs, sultanas and wine. Some fungicides have been found to be effective in preventing fungal growth, but, in other cases, an increase in the synthesis of mycotoxins was reported. Also, the pressure to use less harmful compounds to the environment stimulates the exploration of new and more benign compounds. Synthetic compounds were tested on the growth and OTA production of one strain of A. alliaceus, A. ochraceus, A. carbonarius and A. niger. These new synthetic compounds have a linear structure incorporating urea and/or a phenolic unit. Fungi were grown in yeast extract sucrose (YES) medium supplemented with 50 μM to 200 μM of each one of 20 test compounds in triplicate, for 6 days. Growth was recorded by measuring the diameter of colonies every 24 hours, and OTA was quantified after 5 days of growth using HPLC and fluorescence detection. Growth of the A. ochraceus and the A. carbonarius strains were not inhibited by most of these compounds. However, some led to a decrease in OTA detection. Compounds without the phenolic unit were found to be less effective, while those compounds with urea and phenolic units were the most effective. Growth of the A. alliaceus and of the A. niger strains were inhibited by compound-X by 22 and 27% respectively. This approach will lead to the selection of functional groups able to inhibit the synthesis of OTA which could be incorporated into more powerful antifungal compounds.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/11228/2002, SFRH/BD/3185/2000, SFRH/BPD/12044/2003

Oxidative stress protection by newly synthesized nitrogen compounds with pharmacological potential

In this study we used new nitrogen compounds obtained by organic synthesis whose structure predicted an antioxidant potential and then an eventual development as molecules of pharmacological interest in diseases involving oxidative stress. The compounds, identified as FMA4, FMA5, FMA7 and FMA8 differ in the presence of hydroxyl groups located in the C-3 and/or C-4 position of a phenolic unit, which is possibly responsible for their free radicals buffering capacity. Data from the DPPH discoloration method confirm the high antiradical efficiency of the compounds. The results obtained with cellular models (L929 and PC12) show that they are not toxic and really protect from membrane lipid peroxidation induced by the ascorbate-iron oxidant pair. The level of protection correlates with the drugs lipophilic profile and is sometimes superior to trolox and equivalent to that observed for a-tocopherol. The compounds FMA4 and FMA7 presented also a high protection from cell death evaluated in the presence of a staurosporine apoptotic stimulus. That protection results in a significant reduction of caspase-3 activity induced by staurosporine which by its turn seems to result from a protection observed in the membrane receptor pathway (caspase-8) together with a protection observed in the mitochondrial pathway (caspase-9). Taken together the results obtained with the new compounds, with linear chains, open up perspectives for their use as therapeutical agents, namely as antioxidants and protectors of apoptotic pathways. On the other hand the slight pro-oxidant profile obtained with the cyclic structures suggests a different therapeutic potential that is under current investigation.Fundação para a Ciência e a Tecnologia (FCT) - POCTI and/or FEDER programmes, SFRH/BD/17174/2004, SFRH/BD/3185/2000

Cell adhesion and proliferation of skeletal muscle cells on piezoelectric poly(vinylidene fluoride) membranes

Several body tissues, including bone and muscle, are subjected to electromechanical solicitations during their functional activity [1-3]. Thus, the use of electroactive polymers as active scaffolds shows innovative large potential for tissue engineering applications as it offers functional resemblance to biological clues [2]. In particular, piezoelectric polymers have shown suitability for tissue engineering due to their ability to vary surface charge when a mechanical load is applied [4] and their possibility to be processed in form of films, porous 2D and 3D membranes and scaffolds and fiber mats. The influence of poling state and morphology (film or fiber morphology) of piezoelectric poly(vinylidene fluoride) (PVDF) on the adhesion and morphology of myoblast cells was studied. Non-poled, ‘‘poled +’’ and “poled-’’ !-PVDF films were prepared by solvent casting followed by corona poling. Further, random and aligned electrospun !-PVDF fiber mats were also prepared. It is demonstrated that negatively charged surfaces improve cell adhesion and proliferation and that the directional growth of the myoblast cells can be achieved by culturing the cell on aligned fibers. Therefore, the potential application of electroative materials for muscle regeneration is demonstrated

The importance of ultrasound findings in the study of anal pain

ABSTRACT Objective: endoanal ultrasonography can detect organic causes of anal pain without pathology on physical examination. The aim of this study is to evaluate the importance of endoanal ultrasonography in the diagnosis and therapeutic management of idiopathic and functional anal pain. Material and methods: retrospective study, between 15 March 2005 and 15 June 2008, of all patients with proctalgia and normal examination or with alterations not responsible for anal pain at proctologic exam that have undergone an endoanal ultrasonography. Results: a total of 90 patients were analyzed, with a mean age of 50.5 years, 58% were female. Twenty-three patients had functional anal pain clinic criteria. Endoanal ultrasonography revealed alterations in 49% of patients. The primary findings were changes in sphincters in 14 patients, followed by anal sepsis in 12 patients, anal fissure in 10 patients, perirectal lesions in 6 patients and ulcer of the anal canal in 2 patients. Of the patients with sphincter defects, 5 patients had criteria of chronic anal pain. In this group of patients, no differences were found in manometric and defecographic results between the different ultrasound abnormalities. Conclusions: the endoanal ultrasonography detected occult organic lesions to proctologic examination, in half the patients with anal pain. Ultrasound abnormalities were found in 22% of patients with functional anal pain. However, there was no correlation between ultrasound findings and physiological studies, and therefore could not find etiological or pathogenic factors of functional anal pain

The condensation of salicylaldehydes and malononitrile revisited : synthesis of new dimeric chromene derivatives

The reaction of salicylic aldehydes with malononitrile was reinvestigated, and the reaction pathway was followed by 1H NMR spectroscopy. A delicate control of the experimental conditions allowed the synthesis of 2-imino-2H-chromene-3-carbonitriles 1, (2-amino-3-cyano-4H-chromen-4-yl)malononitriles 2, 4-amino-5-imino-2,7-dimethoxy-5H-chromeno[3,4-c]pyridine-1-carbonitrile 12, and (4,5-diamino-1-cyano-1,10b-dihydro-2H-chromeno[3,4-c]pyridin-2-ylidene)malononitrile 13. Two novel 2-iminochromene dimers, with structures 8 and 9, were isolated and fully characterized. The activity of compound 8a on Aspergillus spp. growth and on ochratoxin A production was evaluated. The results of the bioassays indicate that compound 8a, applied at concentrations of 2 mM, totally inhibited the growth of the fungi tested. Ochratoxin A production by Aspergillus alliaceus was reduced by about 93% with a 200 μM solution of this compound. A moderate inhibitory effect was observed for the analogous structure 8b, and no inhibition was registered for compounds 2 and 1, used as synthetic precursors of the dimeric species 8