Optimization of Tapered Composite Beams

A study on the optimization of tapered composite beams for vibration is conducted. Designers of tapered rotating structural components such as wind mill, helicopter or turbine blades are increasingly considering composite materials as an option to create lighter structures without compromising structural stiffness and to significantly increase their efficiency. In the design of composite material structures, a challenge arises due to a large number of design variables, therefore numerical optimization is required for a better design. Given this, the purpose of this study is to propose an optimization methodology for the design of a tapered beam, considering the vibration constrains present in rotating components. This is achieved by coupling a numerical model which considers the bending modes of vibration, with an optimization algorithm, both coded in MATLAB. Five optimization algorithms, heuristic and deterministic, are coded and compared and the most efficient method is selected. Because the ply orientation angles can assume an infinite number of possible angles, or follow the regular 0 / ±45 / 90 degrees approach, four possible tuning approaches are defined. The beam is optimized for the following design cases of boundary conditions and design requirements: the presence or absence of a tensile axial force, the presence or absence of a taper, three taper configurations, four proposed structural tuning approaches and four boundary conditions. Two of these structural tuning approaches are compared for its influence in the dynamic behavior of the structural component and in achieving better values of in-plane and out-of-plane stresses. The results demonstrate the Genetic Algorithm is an efficient method for optimization, a design analysis is an important step in optimization, and an appropriate tuning approach can improve the overall efficiency of the optimized structure

Stochastic Electrical Detection of Single Ion-Gated Semiconducting Polymers

Semiconducting polymer chains constitute the building blocks for a wide range of electronic materials and devices. However, most of their electrical characteristics at the single-molecule level have received little attention. Elucidating these properties can help understanding performance limits and enable new applications. Here, coupled ionic–electronic charge transport is exploited to measure the quasi-1D electrical current through long single conjugated polymer chains as they form transient contacts with electrodes separated by ≈10 nm. Fluctuations between internal conformations of the individual polymers are resolved as abrupt, multilevel switches in the electrical current. This behavior is consistent with the theoretical simulations based on the worm-like-chain (WLC) model for semiflexible polymers. In addition to probing the intrinsic properties of single semiconducting polymer chains, the results provide an unprecedented window into the dynamics of random-coil polymers and enable the use of semiconducting polymers as electrical labels for single-molecule (bio)sensing assays.</p

Microencapsulation of tomato (Solanum lycopersicon L.) pomace ethanolic extract by spray drying: optimization of process conditions

Microencapsulation by spray-drying is a process used in the stabilization of active compounds from various natural sources, such as tomato by-products, with the purpose to be used as additives in the food industry. The aim of this work was to study the effects of wall material and spray drying conditions on physicochemical properties of microcapsules loaded with lycopene rich extract from tomato pomace. The assays were carried out with ethanolic tomato pomace extract as core material and arabic gum or inulin as wall materials. A central composite rotatable design was used to evaluate the effect of drying air inlet temperature (110–200 C) and concentration of arabic gum (5–35 wt %) or inulin (5–25 wt %) on the antioxidant activity, encapsulation efficiency, loading capacity, and drying yield. SEM images showed that the produced particles were in the category of skin-forming structures. The most suitable conditions, within the ranges studied, to obtain lycopene loaded microparticles were a biopolymer concentration of 10 wt % for both materials and an inlet temperature of 200 and 160 C for arabic gum and inulin, respectively. Arabic gum and inulin possessed a good performance in the encapsulation of tomato pomace extract by spray drying. It is envisaged that the capsules produced have good potential to be incorporated in foods systems with diverse chemical and physical propertiesinfo:eu-repo/semantics/publishedVersio

Influence of ClearT and ClearT2 Agitation Conditions in the Fluorescence Imaging of 3D Spheroids

3D tumor spheroids have arisen in the last years as potent tools for the in vitro screening of novel anticancer therapeutics. Nevertheless, to increase the reproducibility and predictability of the data originated from the spheroids it is still necessary to develop or optimize the techniques used for spheroids' physical and biomolecular characterization. Fluorescence microscopy, such as confocal laser scanning microscopy (CLSM), is a tool commonly used by researchers to characterize spheroids structure and the antitumoral effect of novel therapeutics. However, its application in spheroids' analysis is hindered by the limited light penetration in thick samples. For this purpose, optical clearing solutions have been explored to increase the spheroids' transparency by reducing the light scattering. In this study, the influence of agitation conditions (i.e., static, horizontal agitation, and rotatory agitation) on the ClearT and ClearT2 methods' clearing efficacy and tumor spheroids' imaging by CLSM was characterized. The obtained results demonstrate that the ClearT method results in the improved imaging of the spheroids interior, whereas the ClearT2 resulted in an increased propidium iodide mean fluorescence intensity as well as a higher signal depth in the Z-axis. Additionally, for both methods, the best clearing results were obtained for the spheroids treated under the rotatory agitation. In general, this work provides new insights on the ClearT and ClearT2 clearing methodologies and their utilization for improving the reproducibility of the data obtained through the CLSM, such as the analysis of the cell death in response to therapeutics administration.info:eu-repo/semantics/publishedVersio

Mechanical pruning and soil organic amendments in vineyards of Syrah: effects on grape composition

Aim: The interaction of mechanized pruning systems and soil organic amendment can increase vine productivity. However, since the increase in p roductivity may affect grape composition, this study aimed to understand the effects of the interaction between these two practices. Methods and materials: Two field trials were implemented in Shiraz vineyards in two different wine regions. Mechanical hedge pruning was compared with hand spur pruning and four different organic amendments were tested: biochar, municipal solid waste compost, cattle manure and sewage sludge. Results: Mechanical pruning reduced the total soluble solids (TSS) and pH of the grapes, but had no effects on the other variables. Organic amendments also reduced TSS, especially sewage sludge, and tended to reduce total anthocyanins and total phenols. The effect of the interaction between both factors on grape composition was never significant. A negative relationship between yield and TSS was observed, while titratable acidity had no relationship with yield. Total anthocyanins were also negatively related to yield. A positive relation between TSS and total anthocyanins was also observed. Conclusions: The results show that the combination of mechanical pruning and soil organic amendment is a powerful tool for increasing productivity, but it has some effects on grape composition. Significance and impact of study: The reduction in some fruit composition variables showed that, while mechanical pruning does not significantly affect grape composition, the choice of type and amount of organic amendment will depend on the destination of the grapesinfo:eu-repo/semantics/publishedVersio

Transcriptome analysis of Immune Response against Streptococcus agalactiae infection in the Nile Tilapia GIFT Strain

Streptococcus agalactiae (group B streptococcus, GBS), a broad-spectrum pathogen, causes great economic losses in fish aquaculture, especially the industry of tilapia. Until now, the knowledge of the immune response mechanism against S. agalactiae infection in tilapia has been limited. In the present study, the gill transcriptome of the tilapia from the GBS and the phosphate buffered saline (PBS) groups were sequenced. The transcriptomic analysis results presented the differentially expressed genes (DEGs) at different time points (DEGs number, 6 h: 2122, 9 h: 1851, 15 h: 1791, and 18 h: 2395) after GBS injection, and significantly enriched immune-related gene ontology (GO) terms such as the innate immune response. The significantly enriched immune pathways included the Toll-like receptor signaling pathway, the nucleotide oligomerization domain (NOD)-like receptor signaling pathway, the cytosolic-DNA sensing pathway, and the intestinal immune network for Immunoglobulin A (IgA) production. Most of the DEGs in Toll-like receptor signaling, NOD-like receptor signaling, and cytosolic-DNA sensing pathways presented upregulations at 18 h, which indicated that the innate immune pathways were activated. Two immune-related pathways (phagosome and cell adhesion molecules) were significantly enriched at all time points, suggesting that these two pathways might also play important roles in the immune response against the GBS infection. The results of HE staining showed that the gills of tilapia were damaged seriously at 9 h post-infection, which might be due to the possibility of pyroptosis resulting from the changes of DEGs in the NODlike receptor signaling pathway. This study provided new insight into the mechanisms of gill damage in fish infected with S. agalactiae.info:eu-repo/semantics/publishedVersio

A Leishmania-specific hypothetical protein expressed in both promastigote and amastigote stages of Leishmania infantum employed for the serodiagnosis of, and as a vaccine candidate against, visceral leishmaniasis

Background: LiHyV is an antigenic hypothetical protein present in both promastigote and amastigote stages of Leishmania infantum, which was recently identified by an immunoproteomic approach. A recombinant version of this protein (rLiHyV) was evaluated as a diagnostic marker for canine VL (CVL). In addition, the prophylactic efficacy of the rLiHyV protein, and two of its CD8+ T cell epitopes, has been analyzed in a murine model of visceral leishmaniasis (VL). Methods: Initially, the rLiHyV protein was evaluated by an ELISA technique for the serodiagnosis of CVL. Secondly, vaccines composed of the recombinant protein and both chemically synthesized peptides, combined with saponin as an adjuvant; were administered subcutaneously into BALB/c mice. The cellular and humoral responses generated by vaccination were evaluated. In addition, the parasite burden and immune response were studied 10 weeks after L. infantum infection. Results: The rLiHyV protein was recognized by antibodies of VL dogs. No cross-reactivity was obtained with sera from dogs vaccinated with a Brazilian commercial vaccine, with sera from animals infected with Trypanosoma cruzi, Babesia canis and Ehrlichia canis, or those from non-infected animals living in an endemic area for leishmaniasis. After challenge with L. infantum, spleen cells of BALB/c mice vaccinated with rLiHyV/saponin stimulated with parasite antigens showed a higher production of IFN-γ, IL-12 and GM-CSF, than the same cells obtained from mice vaccinated with the individual peptides, or mice from control (inoculated with saline or saponin) groups. This Th1-type cellular response observed in rLiHyV/saponin vaccinated mice was accompanied by the induction of parasite-specific IgG2a isotype antibodies. Animals immunized with rLiHyV/saponin showed significant reductions in the parasite burden in the liver, spleen, bone marrow and in the lymph nodes draining the paws relative to control mice. Conclusions: The present study showed for the first time that the L. infantum LiHyV protein could be considered as a vaccine candidate against L. infantum infection, as well as a diagnostic marker for CVL.This work was supported by grants from Instituto Nacional de Ciência e Tecnologia em Nanobiofarmacêutica (INCT-Nanobiofar), FAPEMIG (CBB-APQ-00819-12), and CNPq (APQ-472090/2011-9, RHAE-456287/2012-4, APQ-482976/2012-8, and APQ-488237/2013-0). MACF is a grant recipient of FAPEMIG/CAPES. EAFC and APF are grant recipient of CNPq.Peer Reviewe