New expression for the K-shell ionization

A new expression for the total K-shell ionization cross section by electron impact based on the relativistic extension of the binary encounter Bethe (RBEB) model, valid from ionization threshold up to relativistic energies, is proposed. The new MRBEB expression is used to calculate the K-shell ionization cross sections by electron impact for the selenium atom. Comparison with all, to our knowledge, available experimental data shows good agreement

Leprosy presenting as remitting seronegative symmetrical synovitis with pitting oedema syndrome - a case report

Background: Leprosy typically manifests with skin and peripheral nerve involvement. Musculoskeletal complaints are the third most common, and can be the sole presenting manifestation. They range from arthralgia/arthritis in reactional states to full mimics of systemic rheumatic diseases. Remitting Seronegative Symmetrical Synovitis with Pitting Oedema syndrome has only been described once in a patient with already diagnosed Leprosy. Case report: A 68-year-old male, from an endemic region of familial amyloid polyneuropathy, presented with an inaugural Remitting Seronegative Symmetrical Synovitis with Pitting Oedema like syndrome, more that 20 years after travelling to Leprosy endemic areas. Arthritis would resurface whenever oral prednisone was tapered, so methotrexate was started, controlling the complaints. Only one year later, after the appearance of peripheral neuropathy and skin lesions, it was possible to diagnose Leprosy, through the identification of Mycobacterium leprae bacilli in a peripheral nerve biopsy. Conclusion: This report is an example of the heterogeneity of manifestations of Leprosy, namely rheumatic, and the challenge of diagnosing it when typical complaints are absent. It is also a reminder that this disease should be considered whenever a patient with a combination of skin/neurologic/rheumatic complaints has travelled to endemic countries in the past.info:eu-repo/semantics/publishedVersio

Biodiversidad y especiación críptica en los caprélidos (Crustacea: Amphipoda): ¿cuánto falta por descubrir?

La biodiversidad en el medio marino está subestimada, particularmente en el caso de los invertebrados donde la presencia de especies crípticas es más frecuente de lo que se pensaba. Los anfípodos caprélidos, a pesar de su importancia en el medio marino, han sido muy poco estudiados, y esto se debe, en gran parte, a su complicada taxonomía. Así mismo, la tradicional identificación taxonómica basada en caracteres morfológicos sigue siendo la más empleada para identificar y describir las especies de caprélidos, y, dado que la especiación no siempre va acompañada de cambio morfológico (especies crípticas), el uso exclusivo de estos caracteres puede conllevar a una subestimación de su diversidad real. El empleo de metodologías complementarias es, por tanto, necesario. Y, en este sentido, las herramientas moleculares han resultado eficaces y útiles para identificar especies y resolver problemas taxonómicos en estos pequeños crustáceos marinos. En el presente trabajo se muestra una pequeña revisión de los resultados obtenidos para diferentes especies del género Caprella. Estos resultados, que muestran la existencia de nuevas especies, muchas de ellas crípticas, indican que la diversidad de los caprélidos está subestimada, y que la especiación críptica parece ser un fenómeno muy importante y frecuente en estos organismos.Fondo Europeo de Desarrollo Regional POCTI/BSE/42300/2001, FCOMP-01- 0124-FEDER-PTDC/MAR/118205/201

Avaliação físico-química e bioquímica de efluentes infiltrados de laticínio.

bitstream/item/89806/1/BOP-25.pd

Caracterização bioquímica e molecular de doentes com diagnóstico clínico de Dislipidemia Familiar Combinada

A Dislipidemia Familiar Combinada (FCHL) é uma doença poligénica caracterizada por hiperlipidemia simples ou combinada, variabilidade intra-individual e intra-familiar do perfil lipídico, ApoB elevada (> 120 mg/dL) e risco elevado de doença cardiovascular (DCV). A sua causa é desconhecida mas alterações nos genes LPL, APOAIV, APOAV, APOCIII e USF1 parecem contribuir para o seu fenótipo. O objectivo deste estudo é caracterizar bioquímica e molecularmente doentes com diagnóstico clínico de FCHL. Todos os exões e promotor dos genes LPL, APOAIV, APOAV, APOCIII e regiões do gene USF1 (s1,s2) de 41 doentes foram amplificados por PCR e sequenciados. O colesterol total (CT), c-LDL, c-HDL, sdLDL, trigliceridos (TG), apoB e apoCIII foram determinados num aparelho automatizado. Em alguns doentes as sdLDL foram também analisadas por electroforese de lipoproteínas. A ApoAIV e ApoAV foram quantificadas por ELISA. Foram encontradas alterações genéticas em 37 doentes, 3 não descritas (APOAIV Q359_E362, APOAV D332fsX336 e APOCIII 3269C>A). O índex com a alteração Q359_E362del apresentou valores normais de apo AIV (15.5 mg/dL) e o índex com a alteração D332fsX336 apresentou valores baixos de apo AV (74.5 ng/mL). Os doentes estudados apresentam valores elevados de CT (285 ± 83 mg/dL), c-LDL (189 ± 85 mg/dL), TG (310 ± 253 mg/dL), e apo CIII (15 ± 4 mg/dL) e valores reduzidos de c-HDL (45 ± 11 mg/dL), sem medicação. Os valores de apoAIV (17,5 ± 10,4 mg/dL) e apoAV (150 ± 135 ng/mL) encontram-se, na maioria dos casos, no intervalo normal assim como os valores de sdLDL (35 ± 18 mg/dL), no entanto alguns casos apresentam valores acima do cut-off para DCV (35 mg/dL). A análise de sdLDL por electroforese foi realizada em 11 doentes, 9 dos quais apresentaram um perfil aterogénico. O valor médio de ApoB destes doentes era de 94 ± 43 mg/dL, mas aproximadamente 70% dos doentes estavam medicados com terapêutica hipolimiante (estatinas e/ou fibratos). Cerca de 30% dos doentes apresentavam DCV prematura. Os resultados obtidos parecem indicar que alterações nos genes estudados influenciam o fenótipo da FCHL. Os níveis séricos de apo CIII encontram-se alterados nesta dislipidemia. Doentes com FCHL, apesar de estarem medicados, apresentam valores elevados de sdLDL, evidenciando o seu elevado risco cardiovascular. A caracterização bioquímica complementa a identificação genética e permite uma melhor avaliação do risco cardiovascular do doente bem como a escolha de uma terapêutica adequada

PimT, an amino acid exporter controls polyene production via secretion of the quorum sensing pimaricin-inducer PI-factor in Streptomyces natalensis

<p>Abstract</p> <p>Background</p> <p>Polyenes represent a major class of antifungal agents characterised by the presence of a series of conjugated double bonds in their planar hydroxylated macrolide ring structure. Despite their general interest, very little is known about the factors that modulate their biosynthesis. Among these factors, we have recently discovered a new inducing compound (PI-factor) in the pimaricin producer <it>Streptomyces natalensis</it>, which elicits polyene production in a manner characteristic of quorum sensing. Here, we describe the involvement of an amino-acid exporter from <it>S. natalensis </it>in modulating the expression of pimaricin biosynthetic genes via secretion of the quorum-sensing pimaricin-inducer PI-factor.</p> <p>Results</p> <p>Adjacent to the pimaricin gene cluster lies a member of the RhtB family of amino-acid exporters. Gene deletion and complementation experiments provided evidence for a role for PimT in the export of L-homoserine, L-serine, and L-homoserine lactone. Expression of the gene was shown to be induced by homoserine and by the quorum-sensing pimaricin-inducer PI-factor. Interestingly, the mutant displayed 65% loss of pimaricin production, and also 50% decrease in the production of PI, indicating that PimT is used as PI-factor exporter, and suggesting that the effect in antifungal production might be due to limited secretion of the inducer.</p> <p>Conclusion</p> <p>This report describes the involvement of an amino acid exporter (encoded by <it>pimT </it>in the vicinity of the pimaricin cluster) in modulating the expression of antibiotic biosynthetic genes via secretion of the quorum-sensing pimaricin-inducer PI-factor. The discovery of the participation of amino acid exporters in a signal transduction cascade for the production of polyene macrolides is unexpected, and represents an important step forward towards understanding the regulatory network for polyene regulation. Additionally, this finding constitutes the first detailed characterization of an amino-acid exporter in an Actinomycete, and to our knowledge, the first evidence for the implication of this type of exporters in quorum sensing.</p