From nanoscience to nanoethics: the viewpoint of a scientist

Nanotechnologies are an emerging and multidisciplinary field of research, which is re-cently knowing a growing interest because of the basic and applied scientific break-through. Despite a deep understanding of the nanoscience is far to be achieved, the de-bate about the impact of nano-objects in everyday life is gradually involving both the scientific community and civil society. Here we provide some arguments to reflect upon the so-called “nanoethics”. We will start with a brief introduction about the definition of nanotechnology and then the circularity that links the characterization techniques in comparison with the discovery of nanotechnology will be discussed. Conclusion remarks about the presence of nanotechnology in everyday life will be finally presented

Exploiting the properties of mesoporous thin films

Questa tesi di dottorato si pone l’obbiettivo di esplorare le potenzialità offerte dai film sottili mesoporosi. Questi sistemi, infatti, offrono la possibilità di modulare molte delle loro caratteristiche più peculiari come la composizione chimica delle pareti dei pori, la struttura dei pori e la loro organizzazione e sono inoltre eccellenti matrici per strutture host-guest. Inizialmente, sono stati svolti diversi esperimenti in-situ durante l’autoorganizzazione dei film per indagare alcuni aspetti fondamentali di tale processo e per studiare le proprietà chimico-fisiche delle pareti dei pori. In seguito, sono state sfruttate le proprietà di questi materiali attraverso la funzionalizzazione delle loro strutture porose con coloranti, molecole organiche fotoattive e complessi inorganici. E’ stata anche testata la possibilità di utilizzare i pori come stampi monodispersi per la sintesi di nanoparticelle metalliche. Grazie all’elevata area superficiale e ad una particolare composizione chimica delle pareti dei pori, sono stati realizzati film mesoporosi a base di ossidi misti con proprietà ottiche modulabili. Infine, si è cercato di indurre più di un grado di auto-organizzazione all’interno dello stesso materiale per realizzare film a porosità gerarchica. Tre diverse strategie sono state impiegate per ottenere simultaneamente una macro- e una meso-porosità: stampaggio diretto con nanoparticelle fluorurate, separazione di fase controllata mediante l’aggiunta di un agente costampante e cristallizzazione controllata di un sale inorganico. I risultati presentati in questa tesi di dottorato dimostrano la versatilità dei sistemi mesoporosi per la realizzazione di materiali avanzati funzionali con un’ampia varietà di proprietà chimiche e morfologiche.Mesoporous materials show the possibility to tailor several of their characteristic features such as pore structure and arrangement, chemical composition of the pore walls, and, in addition, are excellent matrixes for host-guest systems. This doctoral work explores many of the potentialities offered by mesoporous thin films to produce advanced functional materials with a wide range of tunability in terms of properties and morphology. The first aim was to promote a basic study of self-assembly by in-situ experiments to reveal some fundamental aspects of the process and some chemicalphysical properties of the pore walls. Then, a full set of experiments was dedicated to exploit the mesoporous materials by functionalizing their porous structures with dyes, organic photoactive molecules and inorganic complexes. The pores were also used as a nanoreactor for controlled growth of metallic nanoparticles. Mesoporous mixed oxides films with tunable optical properties were obtained by using the high surface area and controlling the chemical composition of the pore walls. Finally, the possibility of inducing more than one degree of self-organization in the same material, to design hierarchical porous films, was also explored. Three different strategies were used to obtain macro- and meso-porosity, which include direct templating with fluorinated nanoparticles, controlled phase separation using a co-templating agent and controlled crystallization of an inorganic salt

Thermal Induced Polymerization of l-Lysine forms Branched Particles with Blue Fluorescence

AbstractThe polycondensation of amino acids can originate complex polymers that display fascinating structural and optical properties. Thermally induced amidation of l‐lysine allows forming a branched polymer without the support of any catalyst. The polycondensation is completed at 240–250 °C; at higher temperatures, the amino acid degrades. The obtained polylysine particles have been studied by transmission electron microscopy (TEM), nuclear magnetic resonance, and infrared spectroscopy that allow for investigating the different steps of the synthesis. The resulting structure is characterized by peculiar optical properties, e.g., excitation‐dependent blue fluorescence and good quantum efficiency. Hydrogen bonds and the interactions of the amino acids are considered responsible for the optical properties of both l‐lysine monomer solutions at high concentrations and the branched nanopolymers

Thyroid hormones in donkey blood and milk: correlations with milk yield and environmental temperatures

Thyroid hormones (TH) are the primary endocrine stimulators of non-shivering thermogenesis and are known to stimulate lactation. Triiodothyronine (T3) is the bioactive form, mainly derived by deiodination of thyroxine (T4), and the free quote (unbound to plasma proteins) is immediately bioavailable. This study aimed to evaluate potential relationships among TH in the blood, triiodothyronine in the milk (T3M), milk yield and environmental temperature in March to July for 8 lactating donkeys. Milk yield and blood TH concentrations changed significantly over time, whereas T3M was rather stable among individuals and not affected by time of sampling. Free T3 was not correlated with free T4 or with total TH in the blood, but was weakly correlated with T3M. No relationship was found between blood TH and milk yield, which was negatively correlated with T3M, thus the absolute quantity of bioactive hormone in milk secretion is maintained. Milk yield was positively correlated with the free/total T3 and free T3/free T4 ratios and, thus, with the relative quote of the circulating bioactive hormone. Circulating T3/T4 ratios were negatively correlated with environmental temperature. It is concluded that environmental temperature, in the range of the present study (-2 to 35 °C), does not significantly entrain thyroid gland activity, which is affected more by other factors, such as inter-individual variations and physiological status (i.e., stage of lactation). However, increases in environmental temperature most likely induced decreases in deiodinase activity at the peripheral tissue level, as indicated by the decrease in the T3/T4 ratios in the blood

Fulleropyrrolidine-functionalized ceria nanoparticles as a tethered dual nanosystem with improved antioxidant properties

Combining nanoceria and fulleropyrrolidine in a tethered nanosystem allows for efficient scavenging of reactive oxygen species and improved protection of mouse fibroblast cells exposed to a UV insult

Plant extracts in swine nutrition: Effects on some hematochemical parameters and sensory characteristics

There is an increasing public interest in the use of plant extracts in livestock feed. The objective of this study was to investigate the effects of inclusion of oregano (Origanum vulgare L) and chestnut wood (Castanea sativa) extract in pig diets, on some blood parameters, and chemical and sensory characteristics of the meat pork. Ninety Suffolk hybrids pigs were randomly divided into 6 groups (3 indoor and 3 outdoor; 15 animals/group) and, after the adaptation period, both indoor and outdoor pigs were assigned to one of the following iso-nitrogenous and iso-energetic diets: a) control, a commercial pellet diet (16.0% CP, 4.3% CF, 1.0% Lysine produced by Nuovo Molino, in Bastia Umbra, PG); b) control with 0.2% oregano essential oil; c) control with 0.2% oregano + 0.2% natural extract of chestnut wood. Diets were administered for 190 d until slaughter. Blood samples were taken at the beginning (s 1), after 120 (s 2) and at the end of the trial (s 3) to check the health status of animals by some minerals and hematochemical determinations (Ca, P, Zn, Cu, Mg, Fe, total protein, beta-hydroxibutyrate, free fatty acids, tryglicerids, cholesterol, LDLcholesterol) measured with an automatic analyzer (Hitachi 74); whereas the chemical characteristics and sensory quality of the pork were investigated, the first, on a mincemeat separately prepared from carcass (n. 3 animals) of each diet group and on derived matured salami, the second only on the derived matured salami. In conclusion, the diet integrated with plants extracts didn’t interfere with the animal health status or the minerals and hematochemical blood parameters investigated. However, the chemical parameters of the salami showed statistically significant differences especially as regards to the content of lipids and cholesterol, lower in outdoor pigs respectively for 20% and 40%. By contrast, the “consumer test” used to assess whether the consumer perceives sensory differences on the final products showed that the salami made from indoor pigs were significantly more appreciated by consumers (P0,05), regardless of the type of the diet followed by the animal. Then is possible concluded that the consumer “choice” not coincide with the healthy characteristics of meat

On the stable homotopy of a Z₂-Moore space

Silica-germania thin films are important materials for photonic applications, but synthesis of these films is quite difficult to achieve especially with the task of obtaining a homogeneous structure. We have prepared mesoporous silica-germania films via evaporation-induced self-assembly from ethanolic solutions of Si and Ge chlorides, using a triblock copolymer as the templating agent. The mesostructure has been found to have tetragonal symmetry, and the degree of order decreased with increasing Ge content. X-ray photoelectron spectroscopy has shown that the chemical composition of the films is close to the nominal composition. Infrared analysis has revealed that the pore walls are highly condensed and residual hydroxyls are present as isolated. or hydrogen bonded silanols in short chains. UV-vis absorption and photoluminescence spectra have been correlated with the presence of photoactive oxygen-deficient Ge2+ centers which can give rise to a variation in the refractive index upon high-power density UV irradiation

graphene mediated surface enhanced raman scattering in silica mesoporous nanocomposite films

Highly performing mesoporous nanocomposite films with embedded exfoliated graphene and gold nanoparticles display a significant enhancement of G-SERS properties

Thermal-induced phase transitions in self-assembled mesostructured films studied by small-angle X-ray scattering

Two examples of phase transition in self-assembled mesostructured hybrid thin films are reported. The materials have been synthesized using tetraethoxysilane as the silica source hydrolyzed with or without the addition of methyltriethoxysilane. The combined use of transmission electron microscopy, small-angle X-ray scattering and computer simulation has been introduced to achieve a clear identification of the organized phases. A structural study of the self-assembled mesophases as a function of thermal treatment has allowed the overall phase transition to be followed. The initial symmetries of mesophases in as-deposited films have been linked to those observed in samples after thermal treatment. The monodimensional shrinkage of silica films during calcination has induced a phase transition from face-centered orthorhombic to body-centered cubic. In hybrid films, instead, the phase transition has not involved a change in the unit cell but a contraction of the cell parameter normal to the substrate

Mesoscale organization of titania thin films enables oxygen sensing at room temperature

The application of titania materials to gas sensing devices based on thin films are of limited utility because they only operate at a high working temperature and exhibit in general a low sensitivity. To overcome these constraints, a new type of oxygen sensor based on mesoporous titania thin films working at room temperature under UV irradiation has been developed. The increased density of charge carriers induced by the photoconductive effect, has been used to enhance the sensitivity of the thin oxide layers. Mesostructured titania films have been prepared via self-assembly and thermal processing to remove the organic template obtaining anatase nanocrystals. The mesoporous films show a striking decrease of the current in the presence of oxygen that acts as an electron scavenger. Mesoporous samples exhibit a much higher response with respect to dense titania, due to the higher surface area and the larger number of surface defects.RAS is acknowledged for funding this project through CRP 30 L.R. 7/2007 ‘‘Bando Capitale Umano ad Alta Qualificazione annualita` 2015’’. This work was partially supported by the project ‘‘Mi ADATTI E L’ABBATTI’’- INSTM-Regione Lombardia project INSTMRL6