CARBOXYLATED-CELLULOSE NANOCRYSTALS PRODUCED FROM LIGNOCELLULOSIC SOURCES AND USED AS BARRIER COATING FOR PET FILMS

The obtainment of Cellulose nanocrystal (CNC) from different cellulosic sources recently gained a great attention due to their physical and mechanical properties. CNC can be extracted from variety of bio-based and renewable sources, such as wood, cotton, bacterial cellulose, tunicate cellulose and softwood cellulose and used as reinforced nanocomposites, functional materials and oxygen-barrier layers. The most important factor affecting the nanocellulose production is the relative proportion of cellulose, hemicellulose, and lignin in the source material. The extraction of CNC from cellulosic materials started with a pre-treatment of biomass involving the complete or partial removal of hemicelluloses, lignin, etc. and isolation of cellulose component. After the separation of matrix materials, controlled hydrolysis of the cellulosic fibers is performed in order to produce colloidal suspensions of cellulose crystals. Using of ammonium persulfate (APS) has recently achieved the obtainment of CNC from different cellulose sources without any pre-treatment. APS, a strong oxidizing agent with high water solubility, is able to produce carboxylated CNC having high crystallinity and active carboxyl groups. The conversion of the carboxylic acid groups to the carboxylate form offers active sites for surface modification and templates for the synthesis of nanoparticles. Incorporation of carboxylated–CNC as a functional layer on different substrates have enhanced the barrier (oxygen permeability), mechanical, optical, and antifog properties of the nanocomposites. The aim of this work was to obtain the CNC from two lignocellulosic sources and to characterize them in terms of morphology, crystallinity, charge density and coating properties in order to use CNC as barrier coating for PET films

Locomotion performance for oscillatory swimming in free mode

Oscillatory swimming of a fishlike body, whose motion is essentially promoted by the flapping tail, has been studied almost exclusively in axial mode under an incoming uniform stream or, more recently, self-propelled under a virtual body resistance. Obviously, both approaches do not consider the unavoidable recoil motions of the real body which have to be necessarily accounted for in a design procedure for technological means. Actually, once combined with the prescribed kinematics of the tail, the recoil motions lead to a remarkable improvement on the resulting swimming performance. An inviscid impulse model, linear in both potential and vortical contributions, is a proper tool to obtain a deeper comprehension of the physical events with respect to more elaborated flow interaction models. In fact, at a first look, the numerical results seem to be quite entangled, since their trends in terms of the main flapping parameters are not easy to be identified and a fair interpretation is obtained by means of the model capability to separate the effects of added mass and vortex shedding. Specifically, a prevailing dependence of the potential contribution on the heave amplitude and of the vortical contribution on the pitch amplitude is instrumental to unravel their combined action. A further aid for a proper interpretation of the data is provided by accounting separately for a geometrical component of the recoil which is expected to follow from the annihilation of any spurious rigid motion in case no fluid interactions occur. The above detailed decomposition of the recoil motions shows, through the numerical results, how the single components are going to influence the main flapping parameters and the locomotion performance as a guide for the design of biomimetic swimmers

Linear Chains of Styrene and Methyl-Styrene Molecules and their Heterojunctions on Silicon: Theory and Experiment

We report on the synthesis, STM imaging and theoretical studies of the structure, electronic structure and transport properties of linear chains of styrene and methyl-styrene molecules and their heterojunctions on hydrogen-terminated dimerized silicon (001) surfaces. The theory presented here accounts for the essential features of the experimental STM data including the nature of the corrugation observed along the molecular chains and the pronounced changes in the contrast between the styrene and methyl-styrene parts of the molecular chains that are observed as the applied bias is varied. The observed evolution with applied bias of the STM profiles near the ends of the molecular chains is also explained. Calculations are also presented of electron transport along styrene linear chains adsorbed on the silicon surface at energies in the vicinity of the molecular HOMO and LUMO levels. For short styrene chains this lateral transport is found to be due primarily to direct electron transmission from molecule to molecule rather than through the silicon substrate, especially in the molecular LUMO band. Differences between the calculated position-dependences of the STM current around a junction of styrene and methyl-styrene molecular chains under positive and negative tip bias are related to the nature of lateral electron transmission along the molecular chains and to the formation in the LUMO band of an electronic state localized around the heterojunction.Comment: 17 pages plus 11 figures. To appear in Physical Review

On the feasibility of the Rayleigh cycle for dynamic soaring trajectories

Dynamic soaring is a flight technique used by albatrosses and other birds to cover large distances without the expenditure of energy, which is extracted from the available wind conditions, as brightly perceived five centuries ago by Leonardo da Vinci. Closed dynamic soaring trajectories use spatial variations of wind speed to travel, in principle, indefinitely over a prescribed area. The application of the concept of closed dynamic soaring trajectories to aerial vehicles, such as UAVs, may provide a solution to improve the endurance in certain missions. The main limitation of dynamic soaring is its dependence on the wind characteristics. More than one century ago, Lord Rayleigh proposed a very simple model, based on the repeated crossing of a step wind profile, presently known as Rayleigh cycle, that provides a clear explanation of the physical phenomenon. The present paper studies the feasibility of closed, single-loop, energy-neutral trajectories for a broad set of wind and vehicle conditions. Through the use of trajectory optimization methods, it was possible to see how the shape of the wind profile, the initial flight conditions and the vehicle constraints influence the required wind strength to perform dynamic soaring trajectories and consequently their feasibility. It was possible to conclude that there are optimal values for the initial airspeed and initial height of the vehicle, that minimize the required wind strength. In addition, it was seen how the structural and aerodynamic constraints of the vehicle affect dynamic soaring at high and low airspeeds respectively. Finally, some new trajectories that can be performed in conditions of excess wind are proposed. The purpose is to maximize the time spent aloft and the path length while maintaining the concept of single-loop, energy-neutral trajectories, making them especially useful for aerial vehicles surveillance applications

Raw and extruded pea (Pisum sativum), faba bean (Vicia faba var. minor) and lupin (Lupinus albus var. multitalia) as alternative protein sources in broiler diets

AbstractResearch on vegetable-based protein sources has grown as a result of the European Union ban on the inclusion of meat and bone meal in diets of agricultural livestock. This together with recent concern over genetically modified soybeans, the protein source of choice for monogastric diets, has sparked research into the identification of some alternative protein sources. The objective of this study was to evaluate the effect of raw or extruded pea (RP and EP), faba beans (RFb and EFb) or lupin (RL and EL) in partial substitution of soybean meal and other starch sources in broiler diets. A total of 462-d-old male Ross chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (3 pens/treatment). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The amount of alternative proteins used as fed basis and for 1-10 d-old and 11-42 d-old growing periods were: RP and EP: 350 g/kg for all diets; RFb..

Posidonia Oceanica And Green Tea Extract As Active Agents For Shelf Life Extension Of Fresh Cut Peach

Nowadays the reduction of food waste and the availability of food all over the world areas are priority keys for society. In this context, the shelf life extension of fresh products in a sustainable way may represent one of the main goals. The aim of the present research work was to extend the shelf life of fresh cut peach slices by using extracts of Posidonia oceanica (POS) and green tea (GT), and compared to the control. Total polyphenols content was assessed by Folin-Ciocalteu method and the antioxidant capacity by DPPH (2,2-Diphenyl-1-Picrylhydrazyl) assay. Antimicrobial activity of the two extracts was initially carried out in vitro by determining the Minimal Inhibitory Concentration (MIC) against Escherichia coli, Listeria innocua, Pseudomonas putida, Staphylococcus aureus, Saccharomyces cerevisiae, Aspergillus niger and Penicillium chrysogenum. The two extracts in vivo on peach slices by dipping were applied (only water for the control), than, slices were placed into low-density polyethylene (LDPE) bag and stored at 3 ± 1°C for up to 7 days. Microbiological analyses, color (L*,a*,b*), total soluble solid (TSS) and titratable acidity (TA) on peach slices were carried out every 3 days. POS showed the highest polyphenols content (615±45 mg Gallic Acid Equivalent/g – mg GAE/g) while GT 526 ± 28 mg GAE/g. The values of EC50, for POS, was 72.42 ± 22.90 mg/L, while for GT 3.80 ± 0.11 mg/L. Trials in vitro showed MIC values of above 2 g/L for POS and above 1 g/L in GT mainly against Gram positive bacteria. POS was also found to lead a growth delay in the case of fungi, approximately 60 h compared to the control. Results related to the Total Aerobic (TAC) and yeasts and moulds (Y&M) counts highlighted that peach slices dipped with POS maintained in the first 5 days of storage the microbiota at lower or analogous levels than those found at t0 (1.80 ± 0.09 log cfu/g respect 2.30 ± 0.11 log cfu/g and 1.80 ± 0.05 log cfu/g respect 1.70 ± 0.03 log cfu/g of the control, respectively for TAC and Y&M). Regarding pomological analysis, after seven days, lightness of the peach slices decreased 28% in POS, 24% in GT and 35% in control. During shelf life TSS increased 8% in the control, 2% in POS and remained unchanged in GT, after seven days. At the same time, TA decreased 30% in POS, 20% in GT treatment and 63% in the control. During the experiment TSS increased in all treatments, more rapidly in the control; meanwhile the TA decreased slowly in treated samples compared to the control. Concluding, Posidonia oceanica and green tea extracts were found able to delay the colour and pomological parameters decay, maintaining a good fruit quality during shelf life. Data already showed evidence a better performance of the Posidonia extract, limiting the growth of microorganisms responsible for fresh fruit deterioration

Implants outcome inserted in different sites

Oral rehabilitation by means dental implants has high standards of success. Recently, a new type of two-pieces spiral implants has been introduced in the market. Since few reports focus of the efficacy of this medical device as a reliable tool for oral rehabilitation, here a retrospective study is reported. In the period June-December 2017 one hundred and two spiral fixtures were inserted, half in females and 51 in males. The median age was 56 \ub1 8 (min-max 36-73 years). Forty-eight implants were inserted in upper jawbone and 54 in mandible. Two implants were lost and thus survival rate (SVR) is 99.9%. Then peri-implant bone resorption was used to investigate the clinical success (success rate, SCR) over time. No implants have a crestal bone resorption greater than 1.5 mm in the first year follow up. No studied variable has an effect on clinical outcome. In conclusion the studied implants have high SCR and SVR so that they are good tools for oral rehabilitation

Dexamethasone blocks the migration of the human neuroblastoma cell line SK-N-SH

Glucocorticoids (Gc) influence the differentiation of neural crestderived cells such as those composing sympathoadrenal tumors like pheochromocytomas, as well as neuroblastomas and gangliomas. In order to obtain further information on the effects of Gc on cells evolving from the neural crest, we have used the human neuroblastoma cell line SK-N-SH to analyze: 1) the presence and the binding characteristics of Gc receptors in these cells, 2) the effect of dexamethasone (Dex) on the migration of SK-N-SH cells, and 3) the effect of Dex on the organization of the cytoskeleton of SK-N-SH cells. We show that: 1) receptors that bind [ 3 H]-Dex with high affinity and high capacity (Kd of 9.6 nM, Bmax of 47 fmol/mg cytosolic protein, corresponding to 28,303 sites/cell) are present in cytosolic preparations of SK-N-SH cells, and 2) treatment with Dex (in the range of 10 nM to 1 µM) has an inhibitory effect (from 100% to 74 and 43%, respectively) on the chemotaxis of SK-N-SH cells elicited by fetal bovine serum. This inhibition is completely reversed by the Gc receptor antagonist RU486 (1 µM), and 3) as demonstrated by fluorescent phalloidin-actin detection, the effect of Dex (100 nM) on SK-NSH cell migration is accompanied by modifications of the cytoskeleton organization that appear with stress fibers. These modifications did not take place in the presence of 1 µM RU486. The present data demonstrate for the first time that Dex affects the migration of neuroblastoma cells as well as their cytoskeleton organization by interacting with specific receptors. These findings provide new insights on the mechanism(s) of action of Gc on cells originating in the neural crest

Pea seeds (Pisum sativum), faba beans (Vicia faba var. minor) and lupin seeds (Lupinus albus var. multitalia) as protein sources in broiler diets: effect of extrusion on growth performance

The effect of extrusion of pea seeds (Pisum sativum) (PS), faba bean (Vicia faba, variety minor) (FB) and lupin seeds (Lupinus albus, variety multitalia) (LS) on broiler performance were evaluated. Four hundred sixty two 1d-old Ross male chicks, Marek vaccinated, were randomly assigned to seven dietary treatments (3 pens per treatment/22 birds per pen). Chicks were floor housed, ad libitum fed isocaloric and isonitrogenous diets and had free access to water. Artificial light was provided 10 h/d. The bulk of the base diet (control diet) was corn (48.8%, 53.7% and 57%), solvent-extracted soy- bean meal (42.8%, 37.3% and 33.4%), corn oil (4.4%, 5.2% and 6.3%), plus synthetic amino acids, minerals, trace minerals and vitamins, respectively for the 1-10d-old, 11-28d-old and 29 to 42d-old growing periods. The amounts of PS, FB and LS used on an as fed basis were: PS and extruded PS (EPS): 353 (1-10d-old), 356 (11-28d-old) and 350 (29- 42d-old) g/kg; FB and extruded FB (EFB): 479 (1-10d-old), 497 (11-28d-old) and 500 (29-42d old) g/kg; LS and extrud- ed LS (ELS): 360 (1-10d-old) and 300 (11-42d-old) g/kg. High levels of pea (350 g/kg) and faba bean (500 g/kg) did not show negative effects on body weight gain (BWG) and bird feed intake compared to control. Lupin at the 300 g/kg level reduced (P< 0.05) the BWG during the finishing period (22 to 42 d), however the effect disappeared over the whole experimental period (1-42 d) compared to the control group. The ELS group had a lower (P< 0.01) feed intake com- pared to the control group and to the LS group. The feed conversion rate (FCR) was similar among groups for the whole experimental period; however during the grower period the FCR was higher (P< 0.05) for the PS, FB and EFB groups com- pared to the control group. Birds consuming the PS diet had a reduced (P< 0.05) eviscerated carcass yield compared to the control group. The breast meat percent yield was higher (P< 0.01) for birds consuming the FB and EFB diets compared to the control group. There were no statistical differences in percent yield of the leg quarters and in blood parameters