3D printing of fine alumina powders by binder jetting

Additive manufacturing of ceramics is still at an early-development stage; however, the huge interest in custom production of these materials has led to the development of different techniques that could provide highly performing devices. In this work, alumina (α-Al₂O₃) components were produced by binder jetting 3D printing (BJ), a powder-based technique that enables the ex-situ thermal treatment of the printed parts. The employment of fine particles has led to high green relative density values (>60 %), as predicted by Lubachevsky-Stillinger algorithm and DEM modelling. Then, extended sintering has been observed on samples treated at 1750 °C that have reached a final density of 75.4 %. Finally, the mechanical properties of the sintered material have been assessed through bending test for flexural resistance and micro-indentation for Vickers hardness evaluation.     

Production of Green Star/Linear PLA Blends by Extrusion and Injection Molding: Tailoring Rheological and Mechanical Performances of Conventional PLA

In this work, bio-based products composed of blends of a star-shaped poly(d ,l -lactide) (star-PDLLA) and a conventional linear poly(l -lactide) (linear-PLLA) are produced by typical large-scale manufacturing techniques for thermoplastic blends. In the first case, the two polymers are blended through melt extrusion, producing pellets that are subsequently compression-molded into the final bio-based polymer films. Alternatively, the star/linear poly(lactide) (PLA) materials are developed by direct blending through injection molding, a process that generally applies after a preblending extrusion step to ensure proper mixing. Thermomechanical degradation induced by the different processes is evaluated, and the performances of the final star/linear PLA products are thoroughly compared. The effect of the short-branched, amorphous, star polymeric component on thermal, mechanical, and rheological properties of the conventional PLLA is comprehensively investigated, revealing that the star-PDLLA incorporation promotes the formation of a more flexible and tougher material with reduced capability of crystallization. Most importantly, star-PDLLA decreases the melt viscosity of the final material, while increasing the shear-thinning behavior, hence facilitating melt flow during manufacturing. Such properties lead to enhanced material ductility and processability, with respect to typically brittle and viscous conventional PLLA-based materials. Moreover, the tuning of final material performances can be achieved by simply varying the star-PDLLA content.     

Different miRNA Profiles in Plasma Derived Small and Large Extracellular Vesicles from Patients with Neurodegenerative Diseases

Identifying biomarkers is essential for early diagnosis of neurodegenerative diseases (NDs). Large (LEVs) and small extracellular vesicles (SEVs) are extracellular vesicles (EVs) of different sizes and biological functions transported in blood and they may be valid biomarkers for NDs. The aim of our study was to investigate common and different miRNA signatures in plasma derived LEVs and SEVs of Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic Lateral Sclerosis (ALS) and Fronto-Temporal Dementia (FTD) patients. LEVs and SEVs were isolated from plasma of patients and healthy volunteers (CTR) by filtration and differential centrifugation and RNA was extracted. Small RNAs libraries were carried out by Next Generation Sequencing (NGS). MiRNAs discriminate all NDs diseases from CTRs and they can provide a signature for each NDs. Common enriched pathways for SEVs were instead linked to ubiquitin mediated proteolysis and Toll-like receptor signaling pathways and for LEVs to neurotrophin signaling and Glycosphingolipid biosynthesis pathway. LEVs and SEVs are involved in different pathways and this might give a specificity to their role in the spreading of the disease. The study of common and different miRNAs transported by LEVs and SEVs can be of great interest for biomarker discovery and for pathogenesis studies in neurodegeneration.     

Status and Perspectives of Biomass Use for Industrial Process Heat for Industrialized Countries

Full reduction of greenhouse gas emissions involves transforming the industrial process heat supply. The status and future perspectives of biomass for industrial heat mainly based on the German example are reviewed, and a more differentiated consideration by a newly introduced method is attempted. The article focuses on temperature levels above 200 °C combined with an individual examination of most energy-consuming industrial subsectors according to the feasibility of biomass utilization. Numerous studies conclude that biomass use will shift substantially from residential to industrial heat. Results indicate that biomass could play a bigger role especially for cement and clinker production, but they indicate also a significant need for further research and development to take final conclusions.     

Antioxidant edible film based on a carrot pectin-enriched fraction as an active packaging of a vegan cashew ripened cheese

An orange-coloured carrot pectin-enriched fraction (CPEF), with 50% uronic acids (42%-methylated), carrying lipophilic carotenoids and α-tocopherol, developed homogeneous calcium-crosslinked films at 0%, 25%, 50%, 75% and 100% CPEF proportions regarding a commercial pectin. CPEF gave higher relative elongation at break (65% for 50% CPEF film) when compared to 0% CPEF film (26% elongation). FTIR spectra showed a decreased intensity in the C = O group of the esterified carboxylate band as the CPEF content increased. CPEF maintained the orange colour (a* ≈ +37) and partly the carotenes (k ≈ 8.62 × 10⁻³ d⁻¹) in films, even under 25 °C light storage. Also, CPEF gave water resistance to dissolution (100% CPEF film: 50% solubility), maintaining film integrity after 24 h soaking. Surface wettability decreased (40° contact angle) when CPEF proportion increased. These characteristics made the 100% CPEF film an efficient antioxidant interface that preserved a vegan cashew ripened cheese of high water activity (0.952) for 60 days at 7 °C, as determined through the assay of thiobarbituric acid-reactive substances (TBARS).     

Composition and potential uses of mesquite pods (Prosopis pallida L): Comparison with carob pods (Ceratonia siliqua L)

The composition of mesquite pods (Prosopis pallida L) (PP), a legume cultivated in the large desert areas of Peru, was studied. These fruits have at the present time very little practical or commercial use. Taking into account the morphological and compositional similarities to Mediterranean carob pods (Ceratonia siliqua L) (CS), which are widely used in the food industry, some applications of PP are considered. PP shows better nutritional properties than CS, mainly owing to its lower polyphenolic content and higher protein digestibility.     

IL-4 induces functional cell-surface expression of CXCR4 on human T cells

Here we report that IL-4 specifically enhances cell surface expression of CXCR4 on resting peripheral and cord blood T cells. Whereas polarized Th2 clones express variable levels of CXCR4, expression of this receptor is undetectable on polarized Th1 clones but can be induced on the latter cells as well, following short-term culture in the presence of IL-4. The IL-4-induced CXCR4 is functional since interaction with its ligand, stromal-derived factor (SDF)-1, activates the p42 MAP-kinase ERK-2. In addition, although CXCR4 expression is down-regulated following stimulation of T cells and T cell clones via CD28 or CD3 and CD2 cell surface molecules, respectively, it is re-induced by IL-4. These data indicate an important role for IL-4 in rendering CD4+ T cells susceptible to infection with HIV via CXCR4, as well as in promoting SDF-1-induced migration of these cells.     

Selective hydrogenation of styrene: Poisoning effect of thiophene

The poisoning effect of thiophene on a commercial selective hydrogenation Pd/Al₂O₃ catalyst, using the styrene hydrogenation to ethylbenzene as a test reaction, has been studied. It was found that the addition of thiophene to the reactants modifies the electronic properties of Pd and also prevents (within certain limits) the catalyst from a subsequent poisoning when a second amount of thiophene is added. These modifications on Pd electronic state have been followed by X-ray photoelectron spectroscopy, and the poison addition has been studied by IR spectroscopy.     

Children's early ability to solve perspective-taking problems.

Piaget and B. Inhelder (1967 [1948]) claimed that, until 9 or 10 yrs of age, children had great difficulty with perspective taking. J. Huttenlocher and C. C. Presson (1979) showed, however, that these problems were linked to conflict between actual and imagined frames of reference; asking what object occupied a specified location with respect to a hypothetical observer (item questions) led to much better performance. The present experiments extend these findings to younger children: 5-yr-olds (Exp 1); 4-yr-olds, for near and far locations but not left and right (Exp 2); 4-yr-olds for left–right questions (Exp 3); and 3-yr-olds (Exp 4). In addition, Exp 4 showed that memory was not the basis for answering. These data show clearly that preschool children can indicate locations relative to another position. (PsycINFO Database Record (c) 2010 APA, all rights reserved)