Otimização das condições de pré-redução do As(V) em extratos do método BCR para quantificação de arsênio por HG-AAS

A determinação de As por espectrometria de absorção atômica com geração de hidretos (HG-AAS) constitui um método simples, sensível, preciso e de baixo custo. Entretanto, essa técnica requer a pré-redução das espécies de As(V), o que se obtém através do uso de agentes redutores como o KI. Em extratos contendo agentes oxidantes, a pré-redução do As é comprometida, como acontece em extratos obtidos pela aplicação do método BCR (acrônimo francês para Community Bureau of Reference) para a extração sequencial de As em sedimentos. O objetivo deste trabalho foi avaliar as condições de redução do As(V) a As(III), de modo a permitir o uso da HG-AAS para a quantificação do arsênio em extratos obtidos a partir do método BCR. Foram avaliadas condições reacionais utilizando KI, L-cisteína e ácido ascórbico. Para cada uma das etapas de extração do método BCR, diferentes condições de pré-redução possibilitaram a detecção quantitativa do As presente. O uso do método BCR para a extração de arsênio em amostras de sedimentos contaminadas e a aplicação das condições de pré-redução do As(V) selecionadas, seguida pela detecção por HG-AAS, forneceram percentagens de recuperação entre 91 e 99 %.

Reliure de : Spectaculorum in susceptione Philippi, Hisp. prin., divi Caroli V, Caes., f., an. 1549, Antverpiae, aeditorum, mirificus apparatus, per Cornelium Scrib. Grapheum,... vere et... accurate descriptus...

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Reliure de : Andreae Vesalii,... Epistola [ad Joachimum Roelants], rationem modumque propinandi radicis Chynae decocti, quo nuper... Carolus V. imperator usus est, pertractans ; et praeter alia quaedam, epistolae cujusdam ad Jacobum Sylvium sententiam recensens, veritatis ac potissimum humanae fabricae studiosis perutilem ; quum qui hactenus in illa nimium Galeno creditum sit, facile commonstret. Accessit quoque locuples rerum et verborum in hac ipsa epistola memorabilium index... [A Francisco Vesalio, auctoris fratre, editum.]

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How to assign a likelihood ratio in a footwear mark case: an analysis and discussion in the light of R v T

This article analyses and discusses issues that pertain to the choice of relevant databases for assigning values to the components of evaluative likelihood ratio procedures at source level. Although several formal likelihood ratio developments currently exist, both case practitioners and recipients of expert information (such as judiciary) may be reluctant to consider them as a framework for evaluating scientific evidence in context. The recent ruling R v T and ensuing discussions in many forums provide illustrative examples for this. In particular, it is often felt that likelihood ratio-based reasoning amounts to an application that requires extensive quantitative information along with means for dealing with technicalities related to the algebraic formulation of these approaches. With regard to this objection, this article proposes two distinct discussions. In a first part, it is argued that, from a methodological point of view, there are additional levels of qualitative evaluation that are worth considering prior to focusing on particular numerical probability assignments. Analyses will be proposed that intend to show that, under certain assumptions, relative numerical values, as opposed to absolute values, may be sufficient to characterize a likelihood ratio for practical and pragmatic purposes. The feasibility of such qualitative considerations points out that the availability of hard numerical data is not a necessary requirement for implementing a likelihood ratio approach in practice. It is further argued that, even if numerical evaluations can be made, qualitative considerations may be valuable because they can further the understanding of the logical underpinnings of an assessment. In a second part, the article will draw a parallel to R v T by concentrating on a practical footwear mark case received at the authors' institute. This case will serve the purpose of exemplifying the possible usage of data from various sources in casework and help to discuss the difficulty associated with reconciling the depth of theoretical likelihood ratio developments and limitations in the degree to which these developments can actually be applied in practice.

Oeuvres complètes de Alfred de Vigny. [V]

Collection : Petite bibliothèque littéraire

Reliure de : Joannis Lodovici Vivis,... de Veritate fidei christianae libri V, in quib. de religionis nostrae fundamentis contra Ethnicos, Judaeos, Agarenos sive Mahumetanos et perverse Christianos plurima... disputantur... [Francisci Craneveldii... in eosdem libros praefatio...]

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Lymphocyte specificity to protein antigens. V. Conformational dependence of activation of cytochrome c-specific T cells.

Variations in the immunogenic and antigenic properties of native and denatured forms of cytochrome c were observed depending on the strain of mouse tested. In C57BL/6 and (C57BL/6 X DBA/2)F1 (BDF1) mice, priming with either native or denatured cytochrome c (apocytochrome c) gave rise to T cell blasts responding in a similar fashion to the two forms of the antigen and to different peptides derived from CNBr cleavage of the protein when tested for proliferation in the presence of C57BL/6 or BDF1 accessory cells. A different pattern of proliferation was observed when apocytochrome c-specific DBA/2 or BDF1 T cell blasts were tested with DBA/2 accessory cells. In this case, no response was obtained to heme peptide 1-65. This was not due to an inability of DBA/2 macrophages to process and present heme peptide 1-65, as they were able to present this antigen to native cytochrome c-specific BDF1 T cell blasts. Thus, it seems that different sets of clones are generated upon priming BDF1 mice with denatured cytochrome c which are able to recognize different sets of peptides depending on the nature of the accessory cells. The results obtained are consistent with the hypothesis that degradation and presentation of native and denatured cytochrome c by macrophages is dependent on the three-dimensional conformation of the protein.

Reliure de : Justini, L. Flori et Ruffi Historiae. - "Fol. AAi" : Trogi Pompeii Historia per Justinum in compendium redacta proxime quam emendatissime edita. - "Fol. L ij" : Ad magnificum comitem Petrum Mariam Rubeum Parmensem Philippi Broaldi ["sic"] Bononiensis epistola, in Lucii Flori Gestorum ro. epithoma. - "Fol. P iiij v°" : Sexti Ruffi, viri consularis, Valentiano Augusto de Historia ro. libellus incipit. - "A la fin" : Habes, candide lector, in hoc volumine non minus utilia quam lepida Justini in Trogum et Flori in Livium, insuper Sexti Ruffi, viri consularis, epithomas nuper castigatissime editas Mediolani, ex Minutiana officina. 1520 pridie kalendas augustas

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