937 resultados para Non nutrient and non toxic dietary components


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Toadfish are fish from the family Batrachoididae that are found in marine and brackish environment around the world. Among the toadfish, Porichthys genus is very common, where Porichthys porosissimus, also called Atlantic Midshipman is found in Southwest Atlantic, from Rio de Janeiro, Brazil to eastern Argentina. There was no consensus about the classification of the genus Porichthys as venomous fish because so far there are no published Studies regarding human envenomations and/or toxic activities induced in animal models. Herein, we report two conclusive envenoming in human beings caused by P porosissimus spines, with clear signs and symptoms that were very important for the development of our experimental studies. We demonstrated that the P. porosissimus spine extract, now venom, can induce nociceptive and edematogenic responses in mice as well an induction of an inflammatory response elicited by intravital microscopy and leukocyte migration. Finally, we identified in the P. porosissimus spine extract, through analysis by mass spectrometry, the presence of proteins previously detected in the venoms of other fish species and other venomous animals. We believe that based on our studies we will dismiss the non-venomous nature of this fish and clarify this issue. (C) 2014 Elsevier Ltd. All rights reserved.

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Free radicals are produced during aerobic cellular metabolism and have key roles as regulatory mediators in signaling processes. Oxidative stress reflects an imbalance between production of reactive oxygen species and an adequate antioxidant defense. This adverse condition may lead to cellular and tissue damage of components, and is involved in different physiopathological states, including aging, exercise, inflammatory, cardiovascular and neurodegenerative diseases, and cancer. In particular, the relationship between exercise and oxidative stress is extremely complex, depending on the mode, intensity, and duration of exercise. Regular moderate training appears beneficial for oxidative stress and health. Conversely, acute exercise leads to increased oxidative stress, although this same stimulus is necessary to allow an up-regulation in endogenous antioxidant defenses (hormesis). Supporting endogenous defenses with additional oral antioxidant supplementation may represent a suitable noninvasive tool for preventing or reducing oxidative stress during training. However, excess of exogenous antioxidants may have detrimental effects on health and performance. Whole foods, rather than capsules, contain antioxidants in natural ratios and proportions, which may act in synergy to optimize the antioxidant effect. Thus, an adequate intake of vitamins and minerals through a varied and balanced diet remains the best approach to maintain an optimal antioxidant status. Antioxidant supplementation may be warranted in particular conditions, when athletes are exposed to high oxidative stress or fail to meet dietary antioxidant requirements. Aim of this review is to discuss the evidence on the relationship between exercise and oxidative stress, and the potential effects of dietary strategies in athletes. The differences between diet and exogenous supplementation as well as available tools to estimate effectiveness of antioxidant intake are also reported. Finally, we advocate the need to adopt an individualized diet for each athlete performing a specific sport or in a specific period of training, clinically supervised with inclusion of blood analysis and physiological tests, in a comprehensive nutritional assessment. (C) 2015 Elsevier Inc. All rights reserved.

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Colorectal cancer (CRC) is a disease whose genesis may include metabolic dysregulation. Cancer stem cells are attractive targets for therapeutic interventions since their aberrant expansion may underlie tumor initiation, progression, and recurrence. To investigate the actions of metabolic regulators on cancer stem cell-like cells (CSC) in CRC, we determined the effects of soybean-derived bioactive molecules and the anti-diabetes drug metformin (MET), alone and together, on the growth, survival, and frequency of CSC in human HCT116 cells. Effects of MET (60 μM) and soybean components genistein (Gen, 2 μM), lunasin (Lun, 2 μM), β-conglycinin (β-con, 3 μM), and glycinin (Gly, 3 μM) on HCT116 cell proliferation, apoptosis, and mRNA/protein expression and on the frequency of the CSC CD133(+)CD44(+) subpopulation by colonosphere assay and fluorescence-activated cell sorting/flow cytometry were evaluated. MET, Gen, and Lun, individually and together, inhibited HCT116 viability and colonosphere formation and, conversely, enhanced HCT116 apoptosis. Reductions in frequency of the CSC CD133(+)CD44(+) subpopulation with MET, Gen, and Lun were found to be associated with increased PTEN and reduced FASN expression. In cells under a hyperinsulinemic state mimicking metabolic dysregulation and without and with added PTEN-specific inhibitor SF1670, colonosphere formation and frequency of the CD133(+)CD44(+) subpopulation were decreased by MET, Lun and Gen, alone and when combined. Moreover, MET + Lun + Gen co-treatment increased the pro-apoptotic and CD133(+)CD44(+)-inhibitory efficacy of 5-fluorouracil under hyperinsulinemic conditions. Results identify molecular networks shared by MET and bioavailable soy food components, which potentially may be harnessed to increase drug efficacy in diabetic and non-diabetic patients with CRC.

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Literature mentions propyl gallate (PG) as a non-toxic synthetic antioxidant that can be used as a food additive due to its high tolerance to heat. It is important to understand the thermal properties and to identify the decomposition products of this substance, since it has been reported to be thermally stable at temperatures as high as 300 °C. Simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry-photovisual (DSC-photovisual), coupled thermogravimetry-infrared spectroscopy (TG-FTIR) analyses and spectroscopic techniques were used to study the food additive PG. The TG-DTA curves, which were performed with the aid of DSC-photovisual, provided information concerning the thermal stability and decomposition profiles of the compound. From the TG-FTIR coupled techniques, it was possible to identify n-propanol as a possible volatile compound released during the thermal decomposition of the antioxidant. A complete spectroscopic characterization in the ultraviolet, visible, near and middle infrared regions was performed in order to understand the spectroscopic properties of PG.

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The main causes of simple diffuse goiter (SDG) and multinodular goiter (MNG) are iodine deficiency, increase in serum thyroid-stimulating hormone (TSH) level, natural goitrogens, smoking, chronic malnutrition, and lack of selenium, iron, and zinc. Increasing evidence suggests that heredity is equally important. Treatment of SDG and MNG still focuses on L-thyroxine-suppressive therapy surgery. Radioiodine alone or preceded by recombinant human TSH stimulation is widely used in Europe and other countries. Each of these therapeutic options has advantages and disadvantages, with acute and long-term side effects.

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The interactions between outdoor bronzes and the environment, which lead to bronze corrosion, require a better understanding in order to design effective conservation strategies in the Cultural Heritage field. In the present work, investigations on real patinas of the outdoor monument to Vittorio Bottego (Parma, Italy) and laboratory studies on accelerated corrosion testing of inhibited (by silane-based films, with and without ceria nanoparticles) and non-inhibited quaternary bronzes are reported and discussed. In particular, a wet&dry ageing method was used both for testing the efficiency of the inhibitor and for patinating bronze coupons before applying the inhibitor. A wide range of spectroscopic techniques has been used, for characterizing the core metal (SEM+EDS, XRF, AAS), the corroded surfaces (SEM+EDS, portable XRF, micro-Raman, ATR-IR, Py-GC-MS) and the ageing solutions (AAS). The main conclusions were: 1. The investigations on the Bottego monument confirmed the differentiation of the corrosion products as a function of the exposure geometry, already observed in previous works, further highlighting the need to take into account the different surface features when selecting conservation procedures such as the application of inhibitors (i.e. the relative Sn enrichment in unsheltered areas requires inhibitors which effectively interact not only with Cu but also with Sn). 2. The ageing (pre-patination) cycle on coupons was able to reproduce the relative Sn enrichment that actually happens in real patinated surfaces, making the bronze specimens representative of the real support for bronze inhibitors. 3. The non-toxic silane-based inhibitors display a good protective efficiency towards pre-patinated surfaces, differently from other widely used inhibitors such as benzotriazole (BTA) and its derivatives. 4. The 3-mercapto-propyl-trimethoxy-silane (PropS-SH) additivated with CeO2 nanoparticles generally offered a better corrosion protection than PropS-SH.

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The last decades have witnessed significant and rapid progress in polymer chemistry and molecular biology. The invention of PCR and advances in automated solid phase synthesis of DNA have made this biological entity broadly available to all researchers across biological and chemical sciences. Thanks to the development of a variety of polymerization techniques, macromolecules can be synthesized with predetermined molecular weights and excellent structural control. In recent years these two exciting areas of research converged to generate a new type of nucleic acid hybrid material, consisting of oligodeoxynucleotides and organic polymers. By conjugating these two classes of materials, DNA block copolymers are generated exhibiting engineered material properties that cannot be realized with polymers or nucleic acids alone. Different synthetic strategies based on grafting onto routes in solution or on solid support were developed which afforded DNA block copolymers with hydrophilic, hydrophobic and thermoresponsive organic polymers in good yields. Beside the preparation of DNA block copolymers with a relative short DNA-segment, it was also demonstrated how these bioorganic polymers can be synthesized exhibiting large DNA blocks (>1000 bases) applying the polymerase chain reaction. Amphiphilic DNA block copolymers, which were synthesized fully automated in a DNA synthesizer, self-assemble into well-defined nanoparticles. Hybridization of spherical micelles with long DNA templates that encode several times the sequence of the micelle corona induced a transformation into rod-like micelles. The Watson-Crick motif aligned the hydrophobic polymer segments along the DNA double helix, which resulted in selective dimer formation. Even the length of the resulting nanostructures could be precisely adjusted by the number of nucleotides of the templates. In addition to changing the structural properties of DNA-b-PPO micelles, these materials were applied as 3D nanoscopic scaffolds for organic reactions. The DNA strands of the corona were organized by hydrophobic interactions of the organic polymer segments in such a fashion that several DNA-templated organic reactions proceeded in a sequence specific manner; either at the surface of the micelles or at the interface between the biological and the organic polymer blocks. The yields of reactions employing the micellar template were equivalent or better than existing template architectures. Aside from its physical properties and the morphologies achieved, an important requirement for a new biomaterial is its biocompatibility and interaction with living systems, i.e. human cells. The toxicity of the nanoparticles was analyzed by a cell proliferation assay. Motivated by the non-toxic nature of the amphiphilic DNA block copolymers, these nanoobjects were employed as drug delivery vehicles to target the anticancer drug to a tumor tissue. The micelles obtained from DNA block copolymers were easily functionalized with targeting units by hybridization. This facile route allowed studying the effect of the amount of targeting units on the targeting efficacy. By varying the site of functionalization, i.e. 5’ or 3’, the outcome of having the targeting unit at the periphery of the micelle or in the core of the micelle was studied. Additionally, these micelles were loaded with an anticancer drug, doxorubicin, and then applied to tumor cells. The viability of the cells was calculated in the presence and absence of targeting unit. It was demonstrated that the tumor cells bearing folate receptors showed a high mortality when the targeting unit was attached to the nanocarrier.

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Cross Reacting Material 197(CRM197) is a Diphteria toxin non toxic mutant that had shown anti-tumor activity in mice and humans. CRM197 is utilized as a specific inhibitor of heparin-binding epidermal growth factor (HB-EGF), that competes for the epidermal growth factor receptor (EGFR), overexpressed in colorectal cancer and implicated in its progression. We evaluated the effects of CRM197 on HT-29 human colon cancer cell line behaviour and, for CRM197 recognized ability to inhibit HB-EGF, its possible effects on EGFR activation. In particular, while HT-29 does not show any reduction of viability after CRM197 treatment, or changes in cell cycle distribution, in EGFR localization or activation, they show a change in gene expression profile analyzed by microarray. This is the first study where the CRM197 treatment on HT-29 show the alteration of a specific and selected number of genes.

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Outdoor bronzes exposed to the environment form naturally a layer called patina, which may be able to protect the metallic substrate. However, since the last century, with the appearance of acid rains, a strong change in the nature and properties of the copper based patinas occurred [1]. Studies and general observations have established that bronze corrosion patinas created by acid rain are not only disfiguring in terms of loss of detail and homogeneity, but are also unstable [2]. The unstable patina is partially leached away by rainwater. This leaching is represented by green streaking on bronze monuments [3]. Because of the instability of the patina, conservation techniques are usually required. On a bronze object exposed to the outdoor environment, there are different actions of the rainfall and other atmospheric agents as a function of the monument shape. In fact, we recognize sheltered and unsheltered areas as regards exposure to rainwater [4]. As a consequence of these different actions, two main patina types are formed on monuments exposed to the outdoor environment. These patinas have different electrochemical, morphological and compositional characteristics [1]. In the case of sheltered areas, the patina contains mainly copper products, stratified above a layer strongly enriched in insoluble Sn oxides, located at the interface with the uncorroded metal. Moreover, different colors of the patina result from the exposure geometry. The surface color may be pale green for unsheltered areas, and green and mat black for sheltered areas [4]. Thus, in real outdoor bronze monuments, the corrosion behavior is strongly influenced by the exposure geometry. This must be taken into account when designing conservation procedures, since the patina is in most cases the support on which corrosion inhibitors are applied. Presently, for protecting outdoor bronzes against atmospheric corrosion, inhibitors and protective treatments are used. BTA and its derivatives, which are the most common inhibitors used for copper and its alloy, were found to be toxic for the environment and human health [5, 6]. Moreover, it has been demonstrated that BTA is efficient when applied on bare copper but not as efficient when applied on bare bronze [7]. Thus it was necessary to find alternative compounds. Silane-based inhibitors (already successfully tested on copper and other metallic substrates [8]), were taken into consideration as a non-toxic, environmentally friendly alternative to BTA derivatives for bronze protection. The purpose of this thesis was based on the assessment of the efficiency of a selected compound, to protect the bronze against corrosion, which is the 3-mercapto-propyl-trimethoxy-silane (PropS-SH). It was selected thanks to the collaboration with the Corrosion Studies Centre “Aldo Daccò” at the Università di Ferrara. Since previous studies [9, 10, 11] demonstrated that the addition of nanoparticles to silane-based inhibitors leads to an increase of the protective efficiency, we also wanted to evaluate the influence of the addition of CeO2, La2O3, TiO2 nanoparticles on the protective efficiency of 3-mercapto-propyl-trimethoxy-silane, applied on pre-patinated bronze surfaces. This study is the first section of the thesis. Since restorers have to work on patinated bronzes and not on bare metal (except for contemporary art), it is important to be able to recreate the patina, under laboratory conditions, either in sheltered or unsheltered conditions to test the coating and to obtain reliable results. Therefore, at the University of Bologna, different devices have been designed to simulate the real outdoor conditions and to create a patina which is representative of real application conditions of inhibitor or protective treatments. In particular, accelerated ageing devices by wet & dry (simulating the action of stagnant rain in sheltered areas [12]) and by dropping (simulating the leaching action of the rain in unsheltered areas [1]) tests were used. In the present work, we used the dropping test as a method to produce pre-patinated bronze surfaces for the application of a candidate inhibitor as well as for evaluating its protective efficiency on aged bronze (unsheltered areas). In this thesis, gilded bronzes were also studied. When they are exposed to the outside environment, a corrosion phenomenon appears which is due to the electrochemical couple gold/copper where copper is the anode. In the presence of an electrolyte, this phenomenon results in the formation of corrosion products than will cause a blistering of the gold (or a break-up and loss of the film in some cases). Moreover, because of the diffusion of the copper salts to the surface, aggregates and a greenish film will be formed on the surface of the sample [13]. By coating gilded samples with PropS-SH and PropS-SH containing nano-particles and carrying out accelerated ageing by the dropping test, a discussion is possible on the effectiveness of this coating, either with nano-particles or not, against the corrosion process. This part is the section 2 of this thesis. Finally, a discussion about laser treatment aiming at the assessment of reversibility/re-applicability of the PropS-SH coating can be found in section 3 of this thesis. Because the protective layer loses its efficiency with time, it is necessary to find a way of removing the silane layer, before applying a new one on the “bare” patina. One request is to minimize the damages that a laser treatment would create on the patina. Therefore, different laser fluences (energy/surface) were applied on the sample surface during the treatment process in order to find the best range of fluence. In particular, we made a characterization of surfaces before and after removal of PropS-SH (applied on a naturally patinated surface, and subsequently aged by natural exposure) with laser methods. The laser removal treatment was done by the CNR Institute of Applied Physics “Nello Carrara” of Sesto Fiorentino in Florence. In all the three sections of the thesis, a range of non-destructive spectroscopic methods (Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), μ-Raman spectroscopy, X-Ray diffractometry (XRD)) were used for characterizing the corroded surfaces. AAS (Atomic Absorption Spectroscopy) was used to analyze the ageing solutions from the dropping test in sections 1 and 2.

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Materials that can mold the flow of elastic waves of certain energy in certain directions are called phononic materials. The present thesis deals essentially with such phononic systems, which are structured in the mesoscale (<1 µm), and with their individual components. Such systems show interesting phononic properties in the hypersonic region, i.e., at frequencies in the GHz range. It is shown that colloidal systems are excellent model systems for the realization of such phononic materials. Therefore, different structures and particle architectures are investigated by Brillouin light scattering, the inelastic scattering of light by phonons.rnThe experimental part of this work is divided into three chapters: Chapter 4 is concerned with the localized mechanical waves in the individual spherical colloidal particles, i.e., with their resonance- or eigenvibrations. The investigation of these vibrations with regard to the environment of the particles, their chemical composition, and the influence of temperature on nanoscopically structured colloids allows novel insights into the physical properties of colloids at small length scales. Furthermore, some general questions concerning light scattering on such systems, in dispute so far, are convincingly addressed.rnChapter 5 is a study of the traveling of mechanical waves in colloidal systems, consisting of ordered and disordered colloids in liquid or elastic matrix. Such systems show acoustic band gaps, which can be explained geometrically (Bragg gap) or by the interaction of the acoustic band with the eigenvibrations of the individual spheres (hybridization gap).rnWhile the latter has no analogue in photonics, the presence of strong phonon scatterers, when a large elastic mismatch between the composite components exists, can largely impact phonon propagation in analogy to strong multiple light scattering systems. The former is exemplified in silica based phononic structures that opens the door to new ways of sound propagation manipulation.rnChapter 6 describes the first measurement of the elastic moduli in newly fabricated by physical vapor deposition so-called ‘stable organic glasses’. rnIn brief, this thesis explores novel phenomena in colloid-based hypersonic phononic structures, utilizing a versatile microfabrication technique along with different colloid architectures provided by material science, and applying a non-destructive optical experimental tool to record dispersion diagrams.rn