Project proposal for the investigation of particle-stabilised emulsions and foams by microgravity experiments

The utilisation of particle-surfactants nanostructures as stabilising agents represents today the technologic and scientific frontier in the stabilisation of liquid films in emulsion and foams. This topic will be addressed by the proposal STEFAN (STabilisation of Emulsions and FoAms by Nanoparticles), proposed by European groups in the framework of the ESA AO-2004 for Life and Physical Sciences and Applied Research projects Similarly to what can be observed for surfactant-stabilised emulsions and foams, microgravity provides ideal conditions for the investigation of the hierarchy of involved objects: interfacial layer, liquid film, dispersed systems foam or emulsion. Microgravity experiments are planned by refurbishing the Experimental Container FASES for the ISS Fluid Science Laboratory and the facility FASTER for the European Drawer Rack, already under development in existing research programmes. Here the scientific guidelines of the project are presented together with examples and preliminary results on the effect of nano-particle-surfactant structures adsorbed at liquid interfaces. First experimental results have been achieved for particle monolayers at the water/air interface and a thermodynamic model was derived to describe the obtained surface pressure-area isotherms.     

Cooperation and Competition in ALIAS: A Logic Framework for Agents that Negotiate

This paper presents ALIAS, an agent architecture based on intelligent logic agents, where the main form of agent reasoning is abduction. The system is particularly suited for solving problems where knowledge is incomplete, where agents may need to make reasonable hypotheses about the problem domain and other agents, and where the raised hypotheses have to be consistent for the overall set of agents. ALIAS agents are pro-active, exhibiting a goal-directed behavior, and autonomous, since each one can solve problems using its own private knowledge base. ALIAS agents are also social, because they are able to interact with other agents, in order to cooperatively solve problems. The coordination mechanisms are modeled by means of LAILA, a logic-based language which allows to express intra-agent reasoning and inter-agent coordination. As an application, we show how LAILA can be used to implement inter-agent dialogues, e.g., for negotiation. In particular, LAILA is well-suited to coordinate the process of negotiation aimed at exchanging resources between agents, thus allowing them to execute the plans to achieve their goals.     

Color balancing of digital photos using simple image statistics

The great diffusion of digital cameras and the widespread use of the internet have produced a mass of digital images depicting a huge variety of subjects, generally acquired by unknown imaging systems under unknown lighting conditions. This makes color balancing, recovery of the color characteristics of the original scene, increasingly difficult. In this paper, we describe a method for detecting and removing a color cast (i.e. a superimposed color due to lighting conditions, or to the characteristics of the capturing device), from a digital photo without any a priori knowledge of its semantic content. First a cast detector, using simple image statistics, classifies the input images as presenting no cast, evident cast, ambiguous cast, a predominant color that must be preserved (such as in underwater images or single color close-ups) or as unclassifiable. A cast remover, a modified version of the white balance algorithm, is then applied in cases of evident or ambiguous cast. The method we propose has been tested with positive results on a data set of some 750 photos.     

Pharmacogenetics Biomarkers and Their Specific Role in Neoadjuvant Chemoradiotherapy Treatments: An Exploratory Study on Rectal Cancer Patients

Background: Pathological complete response (pCR) to neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC) is still ascribed to a minority of patients. A pathway based-approach could highlight the predictive role of germline single nucleotide polymorphisms (SNPs). The primary aim of this study was to define new predictive biomarkers considering treatment specificities. Secondary aim was to determine new potential predictive biomarkers independent from radiotherapy (RT) dosage and cotreatment with oxaliplatin. Methods: Thirty germ-line SNPs in twenty-one genes were selected according to a pathway-based approach. Genetic analyses were performed on 280 LARC patients who underwent fluoropyrimidine-based CRT. The potential predictive role of these SNPs in determining pathological tumor response was tested in Group 1 (94 patients undergoing also oxaliplatin), Group 2 (73 patients treated with high RT dosage), Group 3 (113 patients treated with standard RT dosage), and in the pooled population (280 patients). Results: Nine new predictive biomarkers were identified in the three groups. The most promising one was rs3136228-MSH6 (p = 0.004) arising from Group 3. In the pooled population, rs1801133-MTHFR showed only a trend (p = 0.073). Conclusion: This exploratory study highlighted new potential predictive biomarkers of neoadjuvant CRT and underlined the importance to strictly define treatment peculiarities in pharmacogenetic analyses.     

Effect of dry‐heat treatments on the nutritional value of maize germ

Maize germ is a by‐product of the maize milling process that is characterised by a high nutritional value. Currently, heat treatments are employed to prevent full‐fat maize germ from spoilage. The aim of this research was to study the effect of five dry‐heat treatments on the nutritional value of full‐fat maize germ. The results confirmed that after each dry‐heat treatment, the lipase activity decreases but the use of high temperatures could be detrimental for phytosterol and thiamine concentrations. The main negative effects have been observed after treatments at 140 °C for 30 min and 160 °C for 10 min. No significant difference has been observed for protein, ash or fatty acid contents. The treatment at 140 °C for 20 min resulted an optimal combination between temperature and heating time to inactivate lipase without altering deeply the nutritional value and the colour of maize germ.     

Nano-to-macroporous TiO2 (anatase) by cold sintering process

Cold Sintering Process (CSP) was applied on commercial nanopowders to produce nanostructured TiO₂ anatase with nano-to-macro porosity. Nanoporous TiO₂ based materials were obtained by applying CSP at 150 °C and pressures up to 500 MPa on three TiO₂ nanopowders with different specific surface area (s.s.a. = 50, 90 and 370 m²/g), using water as transient aqueous environment. Although TiO₂ is insoluble in water, a density of 68% and s.s.a. = 117 m²/g were achieved from the powder with the highest specific surface area. A post annealing process at 500 °C increased the density up to 73% with a s.s.a. = 59 m²/g, and the crystallites dimensions passed from 110 Å in the powder to 130 Å in CSP material and 172 Å after post annealing. Finally, macroporosity was produced by using thermoplastic polymer beads as sacrificial templates within TiO₂ nanopowder during CSP, followed by a debonding at 500 °C.     

Water soluble trehalose-derived oligoamides

A new family of oligotrehaluronamides was synthesized through the polycondensation of α,α-trehaluronic acid dimethyl ester and different diamines or polyamines. In particular, diamines with different molecular structure (1,n-alkylene diamines, aromatic diamine, and alkyleneoxydiamine) were used in order to modulate the molecular weights and the physical characteristics of the products, such as T_g, hydrophilic or hydrophobic properties, and solubility. α,α-Trehaluronic acid was obtained from a renewable source as α,α-trehalose. The syntheses of oligotrehaluronamides were carried out in different solvents such as ethanol, methanol, THF and DMSO, using triethylamine as catalyst. All the compounds obtained in this study were characterized through FT-IR and NMR spectroscopy. The molecular weights were evaluated by ¹H-NMR and in some cases compared with those obtained from ESI-MS spectrometry. Glass transition temperatures and melting points were detected by differential scanning calorimetry. Low molecular weight oligoamides, containing several hydroxyl groups, are water-soluble and could be used in water-based formulations.     

Methanol Conversion to Hydrocarbons (MTH) Over H-ITQ-13 (ITH) Zeolite

Product flexibility is key to meeting fluctuating chemicals demands in the future. In this contribution, the methanol to hydrocarbons (MTH) reaction was investigated over two Ge-containing H-ITQ-13 samples, one with needle-like (H-ITQ-13(N), with (Si+Ge)/Al) = 42) and another with plate-like (H-ITQ-13(P), with (Si+Ge)/Al > 100) morphology. The samples were characterised using XRD, BET, SEM/EDS and FTIR spectroscopy, and their MTH performance was compared with the performance of H-ZSM-5 and H-ZSM-22. Similar specific surface areas (413 and 455 m² g^?1 for H-ITQ-13(N) and (P), respectively) and similar acid strength (Δν ~ ?327(?310) cm^?1) was observed for the two H-ITQ-13 samples. Testing of H-ITQ-13(N) at weight hourly space velocity (WHSV) = 2–8 h^?1 at 350–450 °C revealed that C₅₊ alkenes were the main products (35–45 % selectivity at 400 °C), followed by propene and butene. A low but significant selectivity for aromatic products was observed (6–8 % selectivity at 400 °C). Product selectivity was found to be independent of deactivation. The methanol conversion capacity of H-ITQ-13(N) was 120–150 g methanol g^?1 catalyst at 400 °C. Testing H-ITQ-13 at high (30 atm) and ambient pressure, respectively, at 350 °C showed that a high pressure led to enhanced C₅₊ selectivity, but close to a tenfold decrease in methanol conversion capacity. H-ITQ-13(P) was tested at 400 °C and 2 h^?1. It gave lower conversion than H-ITQ-13(N). Furthermore, when compared at the same conversion level, H-ITQ-13(P) gave higher C₅₊ alkene selectivity, lower aromatics selectivity, and a higher propene to ethene ratio than H-ITQ-13(N). The H-ITQ-13 samples yielded a product spectrum intermediate of H-ZSM-22 and H-ZSM-5. The effluent product cut-off of H-ITQ-13 was similar to that of H-ZSM-5 with tetramethylbenzene as the largest significant product, while H-ZSM-22 produced mainly linear and branched alkenes. The lifetime of H-ITQ-13(N) was clearly enhanced compared to H-ZSM-22, but inferior to H-ZSM-5.     

Evaluation of 4-(4-Fluorobenzyl)piperazin-1-yl]-Based Compounds as Competitive Tyrosinase Inhibitors Endowed with Antimelanogenic Effects

There is a considerable attention for the development of inhibitors of tyrosinase (TYR) as therapeutic strategy for the treatment of hyperpigmentation disorders in humans. Continuing in our efforts to identify TYR inhibitors, we describe the design, synthesis and pharmacophore exploration of new small molecules structurally characterized by the presence of the 4-fluorobenzylpiperazine moiety as key pharmacophoric feature for the inhibition of TYR from Agaricus bisporus (AbTYR). Our investigations resulted in the discovery of the competitive inhibitor [4-(4-fluorobenzyl)piperazin-1-yl]-(3-chloro-2-nitro-phenyl)methanone 26 (IC₅₀=0.18 μM) that proved to be ∼100-fold more active than reference compound kojic acid (IC₅₀=17.76 μM). Notably, compound 26 exerted antimelanogenic effect on B16F10 cells in absence of cytotoxicity. Docking analysis suggested its binding mode into AbTYR and into modelled human TYR.