Vibration of skewed cantilever plates and helicoidal shells

Theoretical vibration frequencies and mode shapes are obtained for skewed plates and helicoidal shells with a cantilever boundary. Using Hamilton's law of varying action, a power series solution is developed to obtain converged numerical results for the five lowest frequencies. Effects of geometrical variables such as aspect ratio, sweep angle and shell radius to thickness ratio are investigated. Accuracy of the solution method is substantiated by comparison with existing skewed plate spherical cap, and conical shell results

Colloidal gas aphron extraction of bioactive compounds from brazilian pinot noir grape pomace.

Residues from the food industry are a problem worldwide. Alternatives have been developed in an attempted to extract compounds from fruit pomace in other to apply those as a natural component in different products. This work has the objective to produce two extracts: (1) ethanolic extract and (2) hot water extract; and characterize the chemical composition of these extracts for future application. In sequence an extraction using surfactants (Colloidal Gas Aphron) was applied in order to obtain a more concentrate and pure extract, in a foam form with better physical properties. The ethanolic extraction was more efficient, obtaining 4 times more bioactive compound (in 100g of pomace: 2670.63 mg Gallic Acid; 65.70 mg anthocyanins and 45,564.78 mmol of Trolox). However the CGA was able to concentrate more the compounds from hot water extract, 61.62% of phenolics compounds were concentrated in the Aphron phase

Trapping and aerogelation of nanoparticles in negative gravity hydrocarbon flames

We report the experimental realization of continuous carbon aerogel production using a flame aerosol reactor by operating it in negative gravity (−g; up-side-down configuration). Buoyancy opposes the fuel and air flow forces in −g, which eliminates convectional outflow of nanoparticles from the flame and traps them in a distinctive non-tipping, flicker-free, cylindrical flame body, where they grow to millimeter-size aerogel particles and gravitationally fall out. Computational fluid dynamics simulations show that a closed-loop recirculation zone is set up in −g flames, which reduces the time to gel for nanoparticles by ≈10[superscript 6] s, compared to positive gravity (upward rising) flames. Our results open up new possibilities of one-step gas-phase synthesis of a wide variety of aerogels on an industrial scale

Cationic Peptide Exposure Enhances Pulsed-Electric-Field-Mediated Membrane Disruption

Background: The use of pulsed electric fields (PEFs) to irreversibly electroporate cells is a promising approach for destroying undesirable cells. This approach may gain enhanced applicability if the intensity of the PEF required to electrically disrupt cell membranes can be reduced via exposure to a molecular deliverable. This will be particularly impactful if that reduced PEF minimally influences cells that are not exposed to the deliverable. We hypothesized that the introduction of charged molecules to the cell surfaces would create regions of enhanced transmembrane electric potential in the vicinity of each charged molecule, thereby lowering the PEF intensity required to disrupt the plasma membranes. This study will therefore examine if exposure to cationic peptides can enhance a PEF’s ability to disrupt plasma membranes. Methodology/Principal Findings We exposed leukemia cells to 40 μs PEFs in media containing varying concentrations of a cationic peptide, polyarginine. We observed the internalization of a membrane integrity indicator, propidium iodide (PI), in real time. Based on an individual cell’s PI fluorescence versus time signature, we were able to determine the relative degree of membrane disruption. When using 1–2 kV/cm, exposure to >50 μg/ml of polyarginine resulted in immediate and high levels of PI uptake, indicating severe membrane disruption, whereas in the absence of peptide, cells predominantly exhibited signatures indicative of no membrane disruption. Additionally, PI entered cells through the anode-facing membrane when exposed to cationic peptide, which was theoretically expected. Conclusions/Significance: Exposure to cationic peptides reduced the PEF intensity required to induce rapid and irreversible membrane disruption. Critically, peptide exposure reduced the PEF intensities required to elicit irreversible membrane disruption at normally sub-electroporation intensities. We believe that these cationic peptides, when coupled with current advancements in cell targeting techniques will be useful tools in applications where targeted destruction of unwanted cell populations is desired

Oxidative-Nitrative Stress and Poly (ADP-Ribose) Polymerase Activation 3 Years after Pregnancy

Background: Oxidative-nitrative stress and poly (ADP-ribose) polymerase activation have been previously observed in healthy and gestational diabetic pregnancies, and they were also linked to the development of metabolic diseases. The aim of the present study was to examine these parameters and their correlation to known metabolic risk factors following healthy and gestational diabetic pregnancies. // Methods: Fasting and 2 h postload plasma total peroxide level, protein tyrosine nitration, and poly (ADP-ribose) polymerase activation were measured in circulating leukocytes three years after delivery in women following healthy, “mild” (diet-treated) or “severe” (insulin-treated) gestational diabetic pregnancy during a standard 75 g OGTT. Nulliparous women and men served as control groups. // Results: Fasting plasma total peroxide level was significantly elevated in women with previous pregnancy (B = 0.52 ± 0.13; p < 0 001), with further increase in women with insulin-treated gestational diabetes (B=0 36 ± 0 17; p < 0 05) (R2 = 0 419). Its level was independently related to previous pregnancy (B=0 47 ± 0 14; p < 0 01) and current CRP levels (B=0 06 ± 0 02; p < 0 05) (R2 = 0 306). // Conclusions: Elevated oxidative stress but not nitrative stress or poly (ADP-ribose) polymerase activation can be measured three years after pregnancy. The increased oxidative stress may reflect the cost of reproduction and possibly play a role in the increased metabolic risk observed in women with a history of severe gestational diabetes mellitus

Excess body fat negatively affects bone mass in adolescents

AbstractObjectiveThe aim of this study was to investigate the effects of excess body fat on bone mass in overweight, obese, and extremely obese adolescents.MethodsThis study included 377 adolescents of both sexes, ages 10 to 19 y. Weight, height, body mass index (BMI), bone age, bone mineral content (BMC), and bone mineral density (BMD) were obtained by dual-energy x-ray absorptiometry. The results were adjusted for chronological age and bone age. Comparisons according to nutritional classification were performed by analysis of variance, followed by Tukey test. Linear regression models were used to explain the variation in BMD and BMC in the L1–L4 lumbar spinal region, proximal femur, and whole body in relation to BMI, lean mass, fat mass (FM), and body fat percentage (BF%), considering P < 0.05.ResultsFor all nutritional groups, average bone age was higher than chronological age. In both sexes, weight and BMI values increased from eutrophic to extremely obese groups, except for BMD and BMC, which did not differ among male adolescents, and were smaller in extremely obese than in obese female adolescents (P < 0.01). Significant differences were observed for FM and BF% values among all nutritional groups (P < 0.01). Positive, moderate to strong correlations were detected between BMD and BMC for BMI, lean mass, and FM. A negative and moderate correlation was found between BMC and BF%, and between BMD and BF% at all bone sites analyzed in males and between BF% and spine and femur BMD, in females.ConclusionThe results reveal a negative effect of BF% on bone mass in males and indicate that the higher the BF% among overweight adolescents, the lower the BMD and BMC values

Oxidative-Nitrative Stress and Poly (ADP-Ribose) Polymerase Activation 3 Years after Pregnancy

Background: Oxidative-nitrative stress and poly (ADP-ribose) polymerase activation have been previously observed in healthy and gestational diabetic pregnancies, and they were also linked to the development of metabolic diseases. The aim of the present study was to examine these parameters and their correlation to known metabolic risk factors following healthy and gestational diabetic pregnancies. Methods: Fasting and 2 h postload plasma total peroxide level, protein tyrosine nitration, and poly (ADP-ribose) polymerase activation were measured in circulating leukocytes three years after delivery in women following healthy, "mild" (diet-treated) or "severe" (insulin-treated) gestational diabetic pregnancy during a standard 75 g OGTT. Nulliparous women and men served as control groups. Results: Fasting plasma total peroxide level was significantly elevated in women with previous pregnancy (B = 0.52 +/- 0.13; p < 0.001), with further increase in women with insulin-treated gestational diabetes (B = 0.36 +/- 0.17; p < 0.05) (R(2) = 0.419). Its level was independently related to previous pregnancy (B = 0.47 +/- 0.14; p < 0.01) and current CRP levels (B = 0.06 +/- 0.02; p < 0.05) (R(2) = 0.306). Conclusions: Elevated oxidative stress but not nitrative stress or poly (ADP-ribose) polymerase activation can be measured three years after pregnancy. The increased oxidative stress may reflect the cost of reproduction and possibly play a role in the increased metabolic risk observed in women with a history of severe gestational diabetes mellitus

Effect of juçara powder on colonic bacteria after static in vitro gastrointestinal digestion.

Ref. 378/137. ICDF, 2 a 4 de abril 2019. Na publicação: Gomes, F.;Pereira, D.; Silva, L.; Beres, C.; Santos, K.; Lourdes, C

Extração aquosa do bagaço de uva Merlot resultante de vinificação tinta: obtenção de fibras alimentares e compostos fenólicos.

ISBN: 978-972-8936-28-0. I CLBHort. Editores Paulo César Tavares de Melo, António Calado. 1-4 nov. 2017

Bioacessibilidade de compostos bioativos e potencial antioxidante de polpa de juçara em pó (Euterpe Edulis).

CBCTA. 13 a 16 de agosto de 2018