Patterning and process parameter effects in 3D suspension near-field electrospinning of nanoarrays

The extracellular matrix (ECM) contains nanofibrous proteins and proteoglycans. Nanofabrication methods have received growing interest in recent years as a means of recapitulating these elements within the ECM. Near-field electrospinning (NFES) is a versatile fibre deposition method, capable of layer-by-layer nano-fabrication. The maximum layer height is generally limited in layer-by-layer NFES as a consequence of electrostatic effects of the polymer at the surface, due to residual charge and polymer dielectric properties. This restricts the total volume achievable by layer-by-layer techniques. Surpassing this restriction presents a complex challenge, leading to research innovations aimed at increasing patterning precision, and achieving a translation from 2D to 3D additive nanofabrication. Here we investigated a means of achieving this translation through the use of 3D electrode substrates. This was addressed by in-house developed technology in which selective laser melt manufactured standing pillar electrodes were combined with a direct suspension near-field electrospinning (SNFES) technique, which implements an automated platform to manoeuvre the pillar electrodes around the emitter in order to suspend fibres in the free space between the electrode support structures. In this study SNFES was used in multiple operation modes, investigating the effects of varying process parameters, as well as pattern variations on the suspended nanoarrays. Image analysis of the nanoarrays allowed for the assessment of fibre directionality, isotropy, and diameter; identifying optimal settings to generate fibres for tissue engineering applications

LA DETERMINACIÓN DEL “ELEMENTO HISTÓRICO Y MORAL” DEL VALOR DE LA FUERZA DE TRABAJO

El objetivo de este artículo es discutir la interpretación marxista dominante respecto del significado de lo que Marx llamó el “elemento histórico y moral” del valor de la fuerza de trabajo y ofrecer una lectura alternativa que sea consistente con los fundamentos de la crítica marxiana de la economía política. Para tal fin, en la primera parte del artículo, se realiza una crítica de dicha interpretación basada en el reconocimiento de su génesis histórica y su filiación con la base textual y fundamentos de la crítica marxiana de la economía política. En la segunda parte, se realiza una reconstrucción crítica del legado de Marx respecto a la determinación del valor de la fuerza de trabajo y se presenta una resignificación del elemento histórico y moral en cuestión. A DETERMINAÇÃO DO “ELEMENTO HISTÓRICO E MORAL” DO VALOR DA FORÇA DE TRABALHOO objetivo deste artigo é discutir a interpretação marxista dominante sobre o significado do que Marx chamou de “elemento histórico e moral” do valor da força de trabalho e oferecer uma leitura alternativa atrelada aos fundamentos da crítica marxiana da economia política. Para tanto, na primeira parte do artigo, realizamos uma crítica da interpretação acima citada, baseada no reconhecimento de sua gênese histórica e sua filiação com a base textual e com os fundamentos da crítica marxiana da economia política. Na segunda parte, realizamos uma reconstrução crítica do legado de Marx quanto à determinação do valor da força de trabalho e apresentamos uma ressignificação do elemento histórico e moral em questão.Palavras-chave: Elemento histórico e moral. Valor da força de trabalho. Debates marxistas. Teoria marxista do salário.THE DETERMINATION OF THE “HISTORIC AND MORAL ELEMENT” OF THE VALUE OF LABOUR POWERThe aim of this article is to challenge the prevailing Marxist interpretation of what Marx called the “historical and moral component” of the value of labour-power, and to offer an alternative reading which is consistent with the foundations of the critique of political economy. In order to do so, the first part of the article develops a critique of the aforementioned Marxist view, on the basis of a reconstruction of its historical genesis, its support on textual evidence from Marx’s works and its theoretical consistency with the foundations of the critique of political economy. Subsequently, the second part of the article undertakes a critical reconstruction of Marx’s legacy on the determination of the value of labour-power and proposes a reconsideration of the meaning of its socalled “historical and moral” component.Keywords: Historical and moral element. Value of labour-power. Marxist debates. Marx’s theory of wages.LA DÉTERMINATION DE L “ÉLÉMENT HISTORIQUE ET MORAL” DE LA VALEUR DE LA FORCE DE TRAVAILL’objectif de cet article est de discuter de l’interprétation marxiste dominante de ce que Marx appelait “l’élément historique et moral” de la valeur de la force de travail et d’offrir une lecture alternative liée aux fondements de la critique marxienne de l’économie politique. Pour ce faire, dans la première partie de l’article nous critiquons l’interprétation susmentionnée, fondée sur la reconnaissance de sa genèse historique et son affiliation à la base textuelle et aux fondements de la critique marxienne de l’économie politique. Dans la deuxième partie, nous effectuons une reconstruction critique de l’héritage de Marx concernant la détermination de la valeur de la force de travail et nous y présentons une nouvelle signification de l’élément historique et moral en question.Mots-clés: Elément historique et moral. Valeur de la force de travail. Débats marxistes. Théorie marxiste du salaire