Influence of Print Orientation on Surface Roughness in Fused Deposition Modeling (FDM) Processes

In the present paper, we address the influence of print orientation angle on surface roughnessobtained in lateral walls in fused deposition modelling (FDM) processes. A geometrical model isdefined that considers the shape of the filaments after deposition, in order to define a theoreticalroughness profile, for a certain print orientation angle. Different angles were considered between 5¿and 85¿. Simulated arithmetical mean height of the roughness profile, Ra values, were calculated fromthe simulated profiles. The Ra simulated results were compared to the experimental results, whichwere carried out with cylindrical PLA (polylactic acid) samples. The simulated Ra values were similarto the experimental values, except for high angles above 80¿, where experimental roughness decreasedwhile simulated roughness was still high. Low print orientation angles show regular profiles withrounded peaks and sharp values. At a print orientation angle of 85¿, the shape of the profile changeswith respect to lower angles, showing a gap between adjacent peaks. At 90¿, both simulated andexperimental roughness values would be close to zero, because the measurement direction is parallelto the layer orientation. Other roughness parameters were also measured: maximum height ofprofile, Rz, kurtosis, Rku, skewness, Rsk, and mean width of the profile elements, Rsm. At high printorientation angles, Rz decreases, Rku shifts to positive, Rsk slightly increases, and Rsk decreases,showing the change in the shape of the roughness profiles.Postprint (published version

Performing Immobility in Contemporary Palestinian Theatre

After the Oslo Accords (1993-1995), Palestine has witnessed the consolidation of a closure regime that limits the freedom of movement of its population. This system has located Palestine in a marginal position within the global patterns of mobility and has had an impact in the internal social dynamics and in artistic representation. Theatre can portray, represent and challenge this process of immobilization. Through the analysis of the play Confinement, produced by Al-Harah in 2010, this paper will analyze how theatre can open new spaces of representation which allows alternative narratives within the intricate panorama of the Israeli occupation

Influence of infill and nozzle diameter on porosity of FDM printed parts with rectilinear grid pattern

The aim of the paper is to analyze the effect of nozzle diameter and infill on porosity and pore size of FDM printed specimens with rectilinear grid pattern. Two different nozzle diameters (0.2 and 0.4 mm), as well as four different infill values (20 %, 40 %, 60 % and 80 %) were used. Experimental results for pore size agree with theoretical results. On the contrary, low experimental porosity was obtained, especially for high infill values, because printed samples show fewer pores than expected. The higher infill, the lower porosity and pore size. Higher nozzle diameter implies higher pore size but similar porosity.Postprint (published version

Cell Receptors for Influenza a Viruses and the Innate Immune Response

The interaction of the hemagglutinin (HA) of the influenza A viruses (IAV) with the cell surface is a key factor for entry of the virus and productive infection of the cell. This glycoprotein has affinity for sialic acids (SA), and different strains present specificity for SA bound through α2,3 or α2,6 linkages to the underlying sugar chain, which is usually related with host and cell tropism. Nucleic acid recognizing receptors (mainly RIG-I and Toll-like receptors) are the most extensively studied pattern recognition receptors for IAV. However, due to the ability of the HA of avian, swine, or human influenza viruses to bind differently linked SA and also to the high levels and variability of glycosylations of their major virion glycoprotein components, HA and NA, IAV interacting proteins on the cell surface could also play an important role in initiating different signaling pathways to elicit the immune response in infected cells. But, at present, these processes are not well understood. In this mini-review we discuss how the interactions of IAV with cell surface receptors on immune cells might be important for the induction of specific innate immune responses and as a result, for pathogenicity in humans

The Good, the Bad and the Ugly: How to Retrieve Scientific Articles form the Internet

The Internet is the largest source of scientific information. For a few years now, the role of library resources and scientific databases has been downgraded in comparison with the immediacy and simplicity of Google’s search toolbar when it comes to retrieving scientific articles. With the emergence of the Open Access movement, and especially since funding agencies began to establish it as a mandatory requirement, there has been some lack of understanding about the concept. However, there are three main characters that will help us clarify this: “The Good”, where we find the institutional or thematic repositories and their corresponding discovery tools, which enable us to disseminate our research and to find scientific articles; “the Bad”, where we find pages like Sci-Hub; and “the Ugly”, which are the copyright agreements that we sign with the journals without knowing all the implications that they involve.N

Neuronal SIRT1 Regulates Metabolic and Reproductive Function and the Response to Caloric Restriction.

Sirt1 is an NAD-dependent, class III deacetylase that functions as a cellular energy sensor. In addition to its well-characterized effects in peripheral tissues, emerging evidence suggests that neuronal Sirt1 activity plays a role in the central regulation of energy balance and glucose metabolism. In this study, we generated mice expressing an enzymatically inactive form (N-MUT) or wild-type (WT) SIRT1 (N-OX) in mature neurons. N-OX male and female mice had impaired glucose tolerance, and N-MUT female, but not male, mice had improved glucose tolerance compared with that of WT littermates. Furthermore, glucose tolerance was improved in all mice with caloric restriction (CR) but was greater in the N-OX mice, who had better glucose tolerance than their littermates. At the reproductive level, N-OX females had impaired estrous cycles, with increased cycle length and more time in estrus. LH and progesterone surges were absent on the evening of proestrus in the N-OX mice, suggesting a defect in spontaneous ovulation, which was confirmed by the ovarian histology revealing fewer corpora lutea. Despite this defect, the mice were still fertile when mated to WT mice on the day of proestrus, indicating that the mice could respond to normal pheromonal or environmental cues. When subjected to CR, the N-OX mice went into diestrus arrest earlier than their littermates. Together, these results suggested that the overexpression of SIRT1 rendered the mice more sensitive to the metabolic improvements and suppression of reproductive cycles by CR, which was independent of circadian rhythms