Three-dimensional printed bone scaffolds:The role of nano/micro-hydroxyapatite particles on the adhesion and differentiation of human mesenchymal stem cells

Bone tissue engineering is strongly dependent on the use of three-dimensional scaffolds that can act as templates to accommodate cells and support tissue ingrowth. Despite its wide application in tissue engineering research, polycaprolactone presents a very limited ability to induce adhesion, proliferation and osteogenic cell differentiation. To overcome some of these limitations, different calcium phosphates, such as hydroxyapatite and tricalcium phosphate, have been employed with relative success. This work investigates the influence of nano-hydroxyapatite and micro-hydroxyapatite (nHA and mHA, respectively) particles on the in vitro biomechanical performance of polycaprolactone/hydroxyapatite scaffolds. Morphological analysis performed with scanning electron microscopy allowed us to confirm the production of polycaprolactone/hydroxyapatite constructs with square interconnected pores of approximately 350 µm and to assess the distribution of hydroxyapatite particles within the polymer matrix. Compression mechanical tests showed an increase in polycaprolactone compressive modulus ( E) from 105.5 ± 11.2 to 138.8 ± 12.9 MPa (PCL_nHA) and 217.2 ± 21.8 MPa (PCL_mHA). In comparison to PCL_mHA scaffolds, the addition of nano-hydroxyapatite enhanced the adhesion and viability of human mesenchymal stem cells as confirmed by Alamar Blue assay. In addition, after 14 days of incubation, PCL_nHA scaffolds showed higher levels of alkaline phosphatase activity compared to polycaprolactone or PCL_mHA structures. </jats:p

Diversidade de aranhas arborícolas (Araneae, Arachnida) na serra do Piquiatuba, Santarém, Pará, Brasil / Diversity of arboreal spiders (Araneae, Arachnida) in Serra do Piquiatuba, Santarém, Pará, Brazil

Este inventário foi desenvolvido na Serra de Piquiatuba, inserida na área do 8º Batalhão de Engenharia e Construção (8º BEC), localizado no km 8 da rodovia Santarém–Cuiabá, no município de Santarém, Pará, Brasil. Esta área é caracterizada por um clima quente e úmido, pluviosidade acima de 1900 mm/ano e um alto grau de preservação. As coletas foram realizadas no período diurno (manhã), mensalmente, durante um ano, de julho/2011 a junho/2012, utilizando o guarda-chuva entomológico para amostragem. Foram obtidas 71 amostras, que resultaram na captura de 917 aranhas, distribuídas em 23 famílias e 74 espécies (409 adultos, [44,6%] e 508 imaturos [55,4%]).  A maior abundância de aranhas foi na estação chuvosa (dezembro a junho). As famílias Tetragnathidae, Araneidae, Salticidae, Theridiidae e Uloboridae foram as mais abundantes. Araneidae apresentou maior riqueza, com 25 espécies seguida de Theridiidae (11 espécies) e Salticidae (8 espécies). Após um ano de coletas, a assíntota da curva de acumulação não foi atingida, sendo a menor estimativa de 85.18 (Chao 1) e a maior com 110.88 (Jack 2), mostrando que mais investimento em amostragem devem ser realizados. Esta é a primeira listagem de aranhas de uma área da região oeste do Pará, abrangendo uma área preservada e protegida, como a Serra de Piquiatuba, na área do 8° BEC

Influence of natural and synthetic carotenoids on the color of egg yolk

Carotenoids are incorporated into the diet of laying hens in order to modify the yolk color. A natural source of carotenoids in tropical countries is annatto, which could be used in the diets of hens. This study aimed to evaluate the addition of natural (annatto) and synthetic carotenoids to the diet of laying hens (commercial and alternative) and their effects on yolk color and consumer sensory perception of fresh and stored eggs obtained from two different preparations (boiled and fried). Physicochemical analysis of proximate composition, thiobarbituric acid reactive substances (TBARS), emulsion activity and instrumental color were performed. Cooking caused significant alterations to the moisture in the preparations and this may have directly affected the color intensity, influencing factors related to egg appearance. In this study, 85 % of the panelists indicated that yolk color is an important attribute of the product’s quality. There was no antioxidant effect of the carotenoids in raw eggs. Synthetic additives should be better dosed to obtain the desired effect. Storage did not alter the proximate composition of the eggs

Theory of Functional Connections and Nelder-Mead optimization methods applied in satellite characterization

The growing population of man-made objects with the build up of mega-constellations not only increases the potential danger to all space vehicles and in-space infrastructures (including space observatories), but above all poses a serious threat to astronomy and dark skies. Monitoring of this population requires precise satellite characterization, which is is a challenging task that involves analyzing observational data such as position, velocity, and light curves using optimization methods. In this study, we propose and analyze the application of two optimization procedures to determine the parameters associated with the dynamics of a satellite: one based on the Theory of Functional Connections (TFC) and another one based on the Nelder-Mead heuristic optimization algorithm. The TFC performs linear functional interpolation to embed the constraints of the problem into a functional. In this paper, we propose to use this functional to analytically embed the observational data of a satellite into its equations of dynamics. After that, any solution will always satisfy the observational data. The second procedure proposed in this research takes advantage of the Nealder-Mead algorithm, that does not require the gradient of the objective function, as alternative solution. The accuracy, efficiency, and dependency on the initial guess of each method is investigated, analyzed, and compared for several dynamical models. These methods can be used to obtain the physical parameters of a satellite from available observational data and for space debris characterization contributing to follow-up monitoring activities in space and astronomical observatories.Comment: Submitted to Acta Astronautic

Viscosidade da clara de ovo proveniente de poedeiras de diferentes espécies com aditivos comerciais e naturais

Yolk color and egg white (albumen) cleanliness and viscosity are important parameters by which consumers judge the quality of eggs. This study aimed to investigate changes in albumen viscosity during storage of eggs for up to 36 days from two different commercial laying hen strains (Carijo Barbada and Isa Brown) fed a diet containing annatto (1.5 and 2.0%) or a synthetic additive without synthetic colorants (control). Analyses of humidity, albumen height, pH, viscosity, foam formation, and stability were carried out on eggs. Carijo Barbada strain had smaller albumen, lower humidity and higher egg white viscosity than Isa Brown strain; however, with storage, viscosity lowered significantly on both strains. Initially, the addition of 2.0% of annatto or a synthetic additive increased viscosity in both strains, but with storage only the control maintained longer viscosity. Lower viscosity did not change foam density and stability

Acute Effects of Whole-Body Vibration Exercise on Pain Level, Functionality, and Rating of Exertion of Elderly Obese Knee Osteoarthritis Individuals: A Randomized Study

Introduction: Among chronic diseases, knee osteoarthritis (KOA) is a joint disease that causes important progressive alterations in the articular and periarticular structures, including synovial inflammation. Exercise has been suggested as an intervention to KOA individuals, and studies suggest that whole-body vibration (WBV) exercise decreases pain levels and favours the functionality of KOA individuals. Objective: The aim of the present study is to analyze the acute effects of WBV exercise on pain levels, functionality (Timed Up and Go (TUG test), anterior trunk flexion (ATF)), and rating of exertion of elderly obese KOA individuals. Methods: Thirty-seven individuals with KOA were allocated to a WBV exercise group (WBVEG), n = 19 (15 females/4 males), and a control group (CG), n = 18 (15 females/3 males). WBVEG performed one session of WBV exercise (11 min, using 5 Hz, 2.5, 5.0, and 7.5 mm, 0.12, 0.25, and 0.37 g). Three bouts were performed (working time of 3 min and rest time of 1 min) using a side-alternating vibrating platform (VP). The same position was used in CG; however, the VP was turned off and there was equipment coupled to the VP that emitted a sound like the vibrations. The pain level was evaluated using a visual analog scale (VAS). Functionality was evaluated with a TUG test and ATF. The rating of subjectively perceived exertion was measured with the category ratio CR-10 (BORG Scale CR-10), Results: A reduction of pain levels in WBVEG after the intervention (p = 0.001) and intergroups (p = 0.041) was found. A decrease of TUG test time in both groups (p = 0.001) and intergroups (p = 0.045) was found, while no statistical changes were observed in the Borg Scale score. Significant improvements of flexibility in both groups (p = 0.001) and intergroups (p = 0.043) were found. Conclusion: One session of WBV exercise can lead to important improvements in individuals with KOA, possibly triggered by physiological responses. However, more studies are needed, in this clinical context, to confirm these results