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The laser surface texturing (LST) technique has recently been used to enhance adhesion bond strength in various coating applications and to create structures with controlled hydrophobic or superhydrophobic surfaces. The texturing processing parameters can be adjusted to tune the surface's polarity, thereby controlling the ratio between the polar and dispersed components of the surface free energy and determining its hydrophobic character. The aim of this work is to systematically select appropriate laser and scan head parameters for high-quality surface topography of metal-based materials. A correlation between texturing parameters and wetting properties was made in view of several technological applications, i.e., for the proper growth of conformal layers onto laser-textured metal surfaces. Surface analyses, carried out by scanning electron microscopy and profilometry, reveal the presence of periodic microchannels decorated with laser-induced periodic surface structures (LIPSS) in the direction parallel to the microchannels. The water contact angle varies widely from about 20° to 100°, depending on the treated material (titanium, nickel, etc.). Nowadays, reducing the wettability transition time from hydrophilicity to hydrophobicity, while also changing environmental conditions, remains a challenge. Therefore, the characteristics of environmental dust and its influence on the properties of the picosecond laser-textured surface (e.g., chemical bonding of samples) have been studied while monitoring ambient conditions. [ABSTRACT FROM AUTHOR]

With the goal of substituting a hard metallic material for the soft Ultra High Molecular Weight Polyethylene (UHMWPE) presently used to make the bases of skis for alpine skiing, we used two non-thermodynamic equilibrium surface treatments with ultra-short (7–8 ps) laser pulses to modify the surface of square plates (50 × 50 mm2) made of austenitic stainless steel AISI 301H. By irradiating with linearly polarized pulses, we obtained Laser Induced Periodic Surface Structures (LIPSS). By laser machining, we produced a laser engraving on the surface. Both treatments produce a surface pattern parallel to one side of the sample. For both treatments, we measured with a dedicated snow tribometer the friction coefficient µ on compacted snow at different temperatures (−10 °C; −5 °C; −3 °C) for a gliding speed range between 1 and 6.1 ms−1. We compared the obtained µ values with those of untreated AISI 301H plates and of stone grinded, waxed UHMWPE plates. At the highest temperature (−3 °C), near the snow melting point, untreated AISI 301H shows the largest µ value (0.09), much higher than that of UHMWPE (0.04). Laser treatments on AISI 301H gave lower µ values approaching UHMWPE. We studied how the surface pattern disposition, with respect to the gliding direction of the sample on snow, affects the µ trend. For LIPSS with pattern, orientation perpendicular to the gliding direction on snow µ (0.05) is comparable with that of UHMWPE. We performed field tests on snow at high temperature (from −0.5 to 0 °C) using full-size skis equipped with bases made of the same materials used for the laboratory tests. We observed a moderate difference in performance between the untreated and the LIPSS treated bases; both performed worse than UHMWPE. Waxing improved the performance of all bases, especially LIPSS treated. [ABSTRACT FROM AUTHOR]

The bulk liquid water density data (ρ) are studied in a very large temperature pressure range including also the glass phases. A thorough analysis of their isobars, together with the suggestions of recent thermodynamical studies, gives evidence of two crossovers at T* and P* above which the hydrogen bond interaction is unable to arrange the tetrahedral network that is at the basis of the liquid polymorphism giving rise to the low density liquid (LDL). The curvatures of these isobars, as a function of T, are completely different: concave below P* (where maxima are) and convex above. In both the cases, a continuity between liquid and glass is observed with P* as the border of the density evolution toward the two different polymorphic glasses (low and high density amorphous). The experimental data of the densities of these two glasses also show a markedly different pressure dependence. Here, on the basis of these observations in bulk water and by considering a recent study on the growth of the LDL phase, by decreasing temperature, we discuss the water liquid-liquid transition and evaluate the isothermal compressibility inside the deep supercooled regime. Such a quantity shows an additional maximum that is pressure dependent that under ambient conditions agrees with a recent X-ray experiment. In particular, the present analysis suggests the presence of a liquid-liquid critical point located at about 180 MPa and 197 K. [ABSTRACT FROM AUTHOR]

The synthesis of contaminant-free silver@linear carbon chains (Ag@LCCs) nanohybrid systems, at different Ag/LCCs ratios, by pulsed laser ablation was studied. The ablation products were first characterized by several diagnostic techniques: conventional UV–Vis optical absorption and micro-Raman spectroscopies, as well as scanning electron microscopy, operating in transmission mode. The experimental evidence was confirmed by the theoretical simulations' data. Furthermore, to gain a deeper insight into the factors influencing metal@LCCs biological responses in relation to their physical properties, in this work, we investigated the bioproperties of the Ag@LCCs nanosystems towards a wound-healing activity. We found that Ag@LCC nanohybrids maintain good antibacterial properties and possess a better capability, in comparison with Ag NPs, of interacting with mammalian cells, allowing us to hypothesize that mainly the Ag@LCCs 3:1 might be suitable for topical application in wound healing, independent of (or in addition to) the antibacterial effect. [ABSTRACT FROM AUTHOR]

The last few years have increasingly emphasized the need to develop new active antiviral products obtained from artificial synthesis processes using nanomaterials, but also derived from natural matrices. At the same time, advanced computational approaches have found themselves fundamental in the repurposing of active therapeutics or for reducing the very long developing phases of new drugs discovery, which represents a real limitation, especially in the case of pandemics. The first part of the review is focused on the most innovative nanomaterials promising both in the field of therapeutic agents, as well as measures to control virus spread (i.e., innovative antiviral textiles). The second part of the review aims to show how computer-aided technologies can allow us to identify, in a rapid and therefore constantly updated way, plant-derived molecules (i.e., those included in terpenoids) potentially able to efficiently interact with SARS-CoV-2 cell penetration pathways. [ABSTRACT FROM AUTHOR]

Using nuclear magnetic resonance we study the dynamics of the hydrogen bond (HB) sub-domains in bulk and emulsified water across a wide temperature range that includes the supercooled regime. We measure the proton spin-lattice T1 and spin-spin T2 relaxation times to understand the hydrophilic interactions that determine the properties of water. We use (i) the Bloembergen, Purcell, and Pound approach that focuses on a single characteristic correlation time τc, and (ii) the Powles and Hubbard approach that measures the proton rotational time τθ. We find that when the temperature is low both relaxation times are strongly correlated when the HB lifetime is long, and that when the temperature is high a decrease in the HB lifetime destroys the water clusters and decouples the dynamic modes of the system. [ABSTRACT FROM AUTHOR]

We study the relaxation times ta in the water-methanol system. We examine new data and data from the literature in the large temperature range 163 < T < 335 K obtained using different experimental techniques and focus on how ta affects the hydrogen bond structure of the system and the hydrophobicity of the alcohol methyl group. We examine the relaxation times at a fixed temperature as a function of the water molar fraction XW and observe two opposite behaviors in their curvature when the system moves from high to low T regimes. This behavior differs from that of an ideal solution in that it has excess values located at different molar fractions (XW = 0.5 for high T and 0.75 in the deep supercooled regime). We analyze the data and find that above a crossover temperature T ~ 223 K, hydrophobicity plays a significant role and below it the water tetrahedral network dominates. This temperature is coincident with the fragile-to-strong dynamical crossover observed in confined water and supports the liquid-liquid phase transition hypothesis. At the same time, the reported data suggest that this crossover temperature (identified as theWidom line temperature) also depends on the alcohol concentration. [ABSTRACT FROM AUTHOR]

We study the self-diffusion coefficient and viscosity of a water-glycerol mixture for several glycerol molar fractions as a function of temperature well inside the metastable supercooled regime. We perform NMR experiments and verify that the system has at different concentration a fragileto- strong crossover accompanied by the violation of the Stokes-Einstein relation. We observe that the crossover temperature depends on the water amount. Studying the fractional representation of the Stokes-Einstein relation, we find that in these systems dynamical arrest does not exhibit criticality and the transport parameters have a universal behavior. [ABSTRACT FROM AUTHOR]

We study by means of nuclear magnetic resonance the self-diffusion of protein hydration water at different hydration levels across a large temperature range that includes the deeply supercooled regime. Starting with a single hydration shell (h = 0.3), we consider different hydrations up to h = 0.65. Our experimental evidence indicates that two phenomena play a significant role in the dynamics of protein hydration water: (i) the measured fragile-to-strong dynamic crossover temperature is unaffected by the hydration level and (ii) the first hydration shell remains liquid at all hydrations, even at the lowest temperature. [ABSTRACT FROM AUTHOR]

The thermodynamic response functions of water display anomalous behaviors. We study these anomalous behaviors in bulk and confined water. We use nuclear magnetic resonance (NMR) to examine the configurational specific heat and the transport parameters in both the thermal stable and the metastable supercooled phases. The data we obtain suggest that there is a behavior common to both phases: that the dynamics of water exhibit two singular temperatures belonging to the supercooled and the stable phase, respectively. One is the dynamic fragile-to-strong crossover temperature (TL ≃ 225 K). The second, T* ~ 315 ± 5 K, is a special locus of the isothermal compressibility KT(T, P) and the thermal expansion coefficient αP(T, P) in the P-Tplane. In the case of water confined inside a protein, we observe that these two temperatures mark, respectively, the onset of protein flexibility from its low temperature glass state (TL) and the onset of the unfolding process (T*). [ABSTRACT FROM AUTHOR]

We study the dynamical arrest in an adhesive hard-sphere colloidal system. We examine a micellar suspension of the Pluronic-L64 surfactant in the temperature (T) and volume fraction ([lowercase_phi_synonym]) phase diagram. According to mode-coupling theory (MCT), this system is characterized by a cusp-like singularity and two glassy phases: an attractive glass (AG) phase and a repulsive glass (RG) phase. The T - [lowercase_phi_synonym] phase diagram of this system as confirmed by a previous series of scattering data also exhibits a Percolation Threshold (PT) line, a reentrant behavior (AG-liquid-RG), and a glass-to-glass transition. The AG phase can be generated out of the liquid phase by using T and [lowercase_phi_synonym] as control parameters. We utilize viscosity and nuclear magnetic resonance (NMR) techniques. NMR data confirm all the characteristic properties of the colloidal system phase diagram and give evidence of the onset of a fractal-like percolating structure at a precise threshold. The MCT scaling laws used to study the shear viscosity as a function of [lowercase_phi_synonym] and T show in both cases a fragile-to-strong liquid glass-forming dynamic crossover (FSC) located near the percolation threshold where the clustering process is fully developed. These results suggest a larger thermodynamic generality for this phenomenon, which is usually studied only as a function of the temperature. We also find that the critical values of the control parameters, coincident with the PT line, define the locus of the FSC. In the region between the FSC and the glass transition lines the system dynamics are dominated by clustering effects. We thus demonstrate that it is possible, using the conceptual framework provided by extended mode-coupling theory, to describe the way a system approaches dynamic arrest, taking into account both cage and hopping effects. [ABSTRACT FROM AUTHOR]

Numerous water characteristics are essentially ascribed to its peculiarity to form strong hydrogen bonds that become progressively more stable on decreasing the temperature. However, the structural and dynamical implications of the molecular rearrangement are still subject of debate and intense studies. In this work, we observe that the thermodynamic characteristics of liquid water are strictly connected to its dynamic characteristics. In particular, we compare the thermal behaviour of the isobaric specific heat of water, measured in different confinement conditions at atmospheric pressure (and evaluated by means of theoretical studies) with its configurational contribution obtained from the values of the measured self-diffusion coefficient through the use of the Adam–Gibbs approach. Our results confirm the existence of a maximum in the specific heat of water at about 225 K and indicate that especially at low temperature the configurational contributions to the entropy are dominant. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • EINS is applied to study molecular mobility of Gen/β-CDs inclusion complexes. • At ∼100 K a first anharmonic contribution, due to CH 3 rotations, is observed. • At higher T a second anharmonic process occurs, due to H-bond network relaxation. • The hindered mobility of inclusion complexes is due to "host-guest" interactions. • Dynamics was connected to stability, indicating HP-β-CD as the best carrier. Abstract Elastic incoherent neutron scattering was employed to investigate the molecular mobility of inclusion complexes, formed by two β-cyclodextrin (β-CD) derivatives, namely (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) and methyl-β-cyclodextrin (Me-β-CD), with Genistein (Gen), a phytoestrogen having antioxidant and anticarcinogenic activities, compared to the physical mixtures and single components. The results, collected in the 20–300 K temperature range, revealed a purely vibrational dynamics up to ∼100 K, where a first anharmonic contribution, corresponding to the methyl rotational dynamics, was observed and represented by an Arrhenius trend. At higher temperatures, a second anharmonic process, also found to obey an Arrhenius-like behavior, occurred at T d and was mainly ascribed to the relaxation of the H-bond network formed by host and guest molecules. Enthalpy and entropy changes associated to the activated anharmonic processes were obtained. The picoseconds timescale dynamics was finally connected to the thermal stability, suggesting HP-β-CD as the most effective carrier for Gen. [ABSTRACT FROM AUTHOR]

Aqueous solutions of amphiphilic molecules are characterized by the competition between hydrophilic and hydrophobic interactions. These interactions have a different energetic dependence with the temperature. Whereas hydrophilic interactions have been well characterized, a complete theory for the hydrophobic ones is still lacking as well as the comprehension of the effect that the solvent exerts on the solute and vice versa. In this paper from the measured relaxation time, we evaluated the thermodynamic state functions of water–methanol solutions in the frame of the transition state theory. In particular we study the behavior of the Gibbs free energy, enthalpy and entropy of water, methanol and some of their solutions as a function of both temperature and water molar fraction. Our results indicate that the temperature of about 280 K represents a crossover between two regions dominated by hydrophobicity (high T ) and hydrophilicity (low T ). [ABSTRACT FROM AUTHOR]

The integrated approaches of Foodomics, defined as a discipline that studies food and nutrition domains through the application of advanced omic technologies, represent the new frontier to explain some critical issues in food science. Among several applications of omic sciences in food analysis, Nuclear Magnetic Resonance (NMR) spectroscopy is the most used for the instrumental sensitivity and precision. Furthermore, in the last years the NMR technique known as high-resolution magic angle spinning (HR-MAS) has been successfully applied in the field of food science. In particular, this powerful technique is unique for the analysis of talis qualis samples of food products. The results reported in this review showed the validity of this technique for food characterization and authentication but also for the comprehension of the changes in the metabolic profile due to different conditions. [ABSTRACT FROM AUTHOR]

We use 1H NMR to probe the energy landscape in the protein folding and unfolding process. Using the scheme ⇄ reversible unfolded (intermediate) → irreversible unfolded (denatured) state, we study the thermal denaturation of hydrated lysozyme that occurs when the temperature is increased. Using thermal cycles in the range 295

In this work we study by means of Nuclear Magnetic Resonance spectroscopy the dynamics of the different water clusters that form within a solution with LiCl at eutectic concentration in the temperature range 320–205 K. This solution is considered a model system allowing the investigation of water properties in the deep supercooled regime in its bulk phase. Our data reveal two important dynamical changes occurring at two relevant temperatures for water: the highest temperature coincides with that of the water density maximum (277 K) and the lowest with that of the so-called dynamical crossover ( ≃ 225 K ). We interpret our data in terms of the different influence that the ions exert on water by lowering the temperature and of the tendency that water displays to develop its characteristic hydrogen bond network. [ABSTRACT FROM AUTHOR]

The identification and characterization of wood material represent an ongoing challenge for artefacts of interest in cultural heritage. Fourier transforms infrared spectroscopy (FTIR) and micro-Raman (MRS) spectroscopies and more recently Surface-Enhanced Raman Scattering (SERS), being non-destructive techniques, have been largely used for the analysis of painted wood. In this work, for the first time, the X-ray Computed Tomography (CT), using a CT medical scanner, was adopted to discriminate three types of wood, usually used in the construction of heritage objects. Wood interior features have been identified in CT images processed through the volumetric rendering technique (VRT), without the need to destructively "take out" a piece of the sample. The information at the macroscopic level collected by CT (density, volumes, morphology, etc.) was enriched by the evidence, at the microscopic level, obtained by the Raman and FTIR spectroscopic techniques. So, the samples have been classified in softwood and hardwood, with the advantage with respect to the conventional analytical methods to be able to distinguish specific structures within the cell walls only through the CT diagnostic technique. Ultimately, a new non-destructive approach is proposed to analyze wood-based heritage objects, but which can be also extended to other materials (i.e., pigments, glues, consolidants). • Wood density and structural information can be obtained by medical scanner CT (MSCT). • MSCT together FTIR and Raman allow to analyze wood species for conservation actions. • Multislice CT can be used for effectively studying cultural heritage artefacts. • VRT allows to analyze wood interior features applying 3D medical filter. [ABSTRACT FROM AUTHOR]

NMR spectroscopy has become an experimental technique widely used in food science. The experimental procedures that allow precise and quantitative analysis on different foods are relatively simple. For a better sensitivity and resolution, NMR spectroscopy is usually applied to liquid sample by means of extraction procedures that can be addressed to the observation of particular compounds. For the study of semisolid systems such as intact tissues, High-Resolution Magic Angle Spinning (HR-MAS) has received great attention within the biomedical area and beyond. Metabolic profiling and metabolism changes can be investigated both in animal organs and in foods. In this work we present a proton HR-MAS NMR study on the typical vegetable foods of Mediterranean diet such as the Protected Geographical Indication (PGI) cherry tomato of Pachino, the PGI Interdonato lemon of Messina, several Protected Designation of Origin (PDO) extra virgin olive oils from Sicily, and the Traditional Italian Food Product (PAT) red garlic of Nubia. We were able to identify and quantify the main metabolites within the studied systems that can be used for their characterization and authentication. [ABSTRACT FROM AUTHOR]

The dynamics of a hierarchical colloid solution, dendrimer in methanol, has been studied using photon-correlation spectroscopy (PCS). The obtained relaxation curves are analyzed according to the mode-coupling theory (MCT). The main results are: i) the occurrence of a fragile to strong dynamical crossover as a function of the packing fraction at ϕ c ≃ 0.39, and ii) the observation of a secondary relaxation ( β ) that has its onset just at the dynamical crossover and is correlated with the primary α -relaxation. Finally we discuss the obtained findings in comparison with recent experiments in similar systems characterized by an attractive interaction obtaining a confirmation on the primary role of the dynamical crossover in the physics of the dynamical arrest. [ABSTRACT FROM AUTHOR]

We study by means of the infrared bending vibrational mode the microscopic mechanisms that are at the base of protein irreversible denaturation. In particular, we follow the thermal evolution of the Amide I and II vibrational modes of lysozyme residuals from ambient temperature toward the temperature of irreversible unfolding. Our results indicate that the thermal changes of the coupling, by means of the hydrogen bond, between hydration water molecules and the different chemical groups of the protein are the main microscopic mechanisms underlying the unfolding process. [ABSTRACT FROM AUTHOR]

We have studied the effects of ahigh concentration of butanol and octanol on the phase behavior andon the lateral mobility of 1,2-palmitoyl-sn-glycero-3-phosphocholine(DPPC) by means of differential scanning calorimetry and pulsed-gradientstimulated-echo (PGSTE) NMR spectroscopy. A lowering of the lipidtransition from the gel to the liquid-crystalline state for the membrane–alcoholsystems has been observed. NMR measurements reveal three distinctdiffusions in the DPPC–alcohol systems, characterized by ahigh, intermediate, and slow diffusivity, ascribed to the water, thealcohol, and the lipid, respectively. The lipid diffusion processis promoted in the liquid phase while it is hindered in the interdigitatedphase due to the presence of alcohols. Furthermore, in the interdigitatedphase, lipid lateral diffusion coefficients show a slight temperaturedependence. To the best of our knowledge, this is the first time thatlateral diffusion coefficients on alcohol with so a long chain, andat low temperatures, are reported. By the Arrhenius plots of the temperaturedependence of the diffusion coefficients, we have evaluated the apparentactivation energy in both the liquid and in the interdigitated phase.The presence of alcohol increases this value in both phases. An explanationin terms of a free volume model that takes into account also for energyfactors is proposed. [ABSTRACT FROM AUTHOR]

Abstract: We have studied by means of High Resolution Magic Angle Spinning Nuclear Magnetic Resonance the metabolic profile of the famous Sicilian cherry tomato of Pachino. Thanks to its organoleptic and healthy properties, this particular foodstuff was the first tomato accredited by the European PGI (Protected Geographical Indication) certification of quality. Due to the relatively high price of the final product commercial frauds originated in the Italian and international markets. Hence, there is a growing interest to develop analytical techniques able to predict the origin of a tomato sample, indicating whether or not it originates from the area of Pachino, Sicily (Italy). In this paper we have determined the molar concentration of the metabolites constituent the PGI cherry tomato of Pachino. Furthermore, by means of a multivariate statistical analysis we have identified which metabolites are relevant for sample differentiation. [Copyright &y& Elsevier]

The dynamics of supercooled ortho-terphenyl has been studied using photon-correlation spectroscopy (PCS) in the depolarized scattering geometry. The obtained relaxation curves are analyzed according to the mode-coupling theory (MCT) for supercooled liquids. The main results are: i) the observation of the secondary Johari-Goldstein relaxation (β) that has its onset just at the dynamical crossover temperature TB (TM > TB > Tg); ii) the confirmation, of the suggestion of a recent statistical mechanical study, that such a molecular system remains ergodic also below the calorimetric glass-transition temperature Tg. Our experimental data give evidence that the time scales of the primary (α) and this secondary relaxations are correlated. Finally a comparison with recent PCS experiments in a colloidal system confirms the primary role of the dynamical crossover in the physics of the dynamical arrest. [ABSTRACT FROM AUTHOR]

For centuries mankind has stored its knowledge on paper, a remarkable biomaterial made of natural cellulose fibers. However, spontaneous cellulose degradation phenomena weaken and discolorate paper over time. The detailed knowledge of products arising from cellulose degradation is essential in understanding deterioration pathways and in improving durability of cultural heritage. In this study, for the first time, products of cellulose degradation were individually detected in solid paper samples by means of an extremely powerful proton HR-MAS NMR set-up, in combination to a wise use of both ancient and, as reference, artificially aged paper samples. Carboxylic acids, in addition to more complex dicarboxylic and hydroxy-carboxylic acids, were found in all samples studied. Since these products can catalyze further degradation, their knowledge is fundamental to improve conservation strategies of historical documents. Furthermore, the identification of compounds used in ancient production techniques, also suggests for artifacts dating, authentication and provenance. [ABSTRACT FROM AUTHOR]

The anomalous behavior of thermodynamic response functions is an unsolved problem in the physics of water. The mechanism that gives rise to the dramatic indefinite increase at low temperature in the heat capacity, the compressibility, and the coefficient of thermal expansion, is unknown. We explore this problem by analyzing both new and existing experimental data on the power spectrum S(Q, ω) of bulk and confined water at ambient pressure. When decreasing the temperature, we find that the liquid undergoes a structural transformation coinciding with the onset of an extended hydrogen bond network. This network onset seems to give rise to the marked viscoelastic behavior, consistent with the interesting possibility that the sound velocity and response functions of water depend upon both the frequency and wave vector. [ABSTRACT FROM AUTHOR]

Abstract: We have studied by means of high resolution Nuclear Magnetic Resonance the dynamical and structural properties of water/methanol solutions as a function of temperature and concentration. We measured dynamical quantities such as the self-diffusion coefficient and the spin–lattice relaxation time and structurally dependent quantities like the proton chemical shift of all the chemical groups present in the mixture. In fact, by means of high resolution NMR spectroscopy, it is possible to study separately all the hydrogens belonging to the different functional groups. We argue that the physical properties of the solution are influenced by the interplay between hydrophobic and hydrophilic interactions that in turn depend on the solution concentration and on the temperature. [Copyright &y& Elsevier]

Abstract: The understanding of the physical processes that occur below the threshold of protein thermal denaturation is of fundamental importance. In this thermal region proteins undergo a reversible folding/unfolding process whose evolution depends upon temperature and time. When the kinetics of the folding is altered, the specific biological activity of the protein is altered as well and aggregation phenomena usually intervene. The most important role in driving these processes is played by the solvent and water is certainly the solvent par excellence. It is well known that proteins become biologically active with no less than a water monolayer covering their surface. The knowledge of the physical properties of this monolayer is of basic importance to prevent folding alterations. We present a proton Nuclear Magnetic Resonance study at very high resolution of the thermodynamic properties of lysozyme hydration water as a function of temperature and time in the thermal region of the reversible denaturation. [Copyright &y& Elsevier]

Polymers are widely employed in several fields thanks to their wide versatility and the easy derivatization routes. However, a wide range of commercial polymers suffer from limited use on a large scale due to their inert nature. Nowadays, acrylate and methacrylate polymers, which are respectively derivatives of acrylic or methacrylic acid, are among the most proposed materials for their useful characteristics like good biocompatibility, capping ability toward metal clusters, low price, potentially recyclability and reusability. Here, we discuss the advantages and challenges of this class of smart polymers focusing our attention on their current technological applications in medical, electronic, food packaging and environmental remediation fields. Furthermore, we deal with the main issue of their recyclability, considering that the current commercial bioplastics are not yet able to meet the global needs as much as to totally replace fossil-fuel-based products. Finally, the most accredited strategies to reach recyclable composites based on acrylic polymers are described. [ABSTRACT FROM AUTHOR]

In this review we discuss the role of hydrophilic/hydrophobic interplay in several processes involving water–surface interactions. For this purpose, we describe the self-organization architecture of biomacromolecules, the design of artificial biocompatible nano-devices able to deliver poorly water-soluble drugs, and the engineering of packaging materials capable to preserve food from water, dust, and microorganisms contamination. Material properties together with mutual-cooperative interactions play a crucial role to match the complexity of biological environments and desired functional products. Therefore, the comprehension and description of hydrophilic/hydrophobic interactions at molecular level represent the main steps towards the development of new biosystems with improved functionality. [Display omitted] • H 2 O polymorphic properties tune its interaction with molecular/macroscopic surfaces. • WMI pilot surface functionalization and self-organization of biomolecules. • WMI are crucial in improving drug delivery systems and food packaging materials. [ABSTRACT FROM AUTHOR]

Liquid's behaviour, when close to critical points, is of extreme importance both for fundamental research and industrial applications. A detailed knowledge of the structural–dynamical correlations in their proximity is still today a target to reach. Liquid water anomalies are ascribed to the presence of a second liquid–liquid critical point, which seems to be located in the very deep supercooled regime, even below 200 K and at pressure around 2 kbar. In this work, the thermal behaviour of the self-diffusion coefficient for liquid water is analyzed, in terms of a two-states model, for the first time in a very wide thermal region (126 K < T < 623 K), including those of the two critical points. Further, the corresponding configurational entropy and isobaric-specific heat have been evaluated within the same interval. The two liquid states correspond to high and low-density water local structures that play a primary role on water dynamical behavior over 500 K. [ABSTRACT FROM AUTHOR]

Water is one of the most important compounds on Earth, yet its material properties are still poorly understood. Here, we use a recently developed two-state, two-(time)scale (TS2) dynamic mean-field model combined with the two-state Sanchez–Lacombe (SL) thermodynamic theory in order to describe the equation of state (density as a function of temperature and pressure) and diffusivity of liquid water. In particular, it is shown that in a relatively wide temperature and pressure range (160 K < T < 360 K; 0 < P < 100 MPa), density and self-diffusion obey a special type of dynamic scaling, similar to the "τTV" scaling of Casalini and Roland, but with the negative exponent γ. The model predictions are consistent with experimental data. The new equation of state can be used for various process models and generalized to include multicomponent mixtures. [ABSTRACT FROM AUTHOR]

Intraocular lenses (IOLs) are commonly implanted after surgical removal of a cataractous lens. A variety of IOL materials are currently available, including collamer, hydrophobic acrylic, hydrophilic acrylic, PHEMA copolymer, polymethylmethacrylate (PMMA), and silicone. High-quality polymers with distinct physical and optical properties for IOL manufacturing and in line with the highest quality standards on the market have evolved to encompass medical needs. Each of them and their packaging show unique advantages and disadvantages. Here, we highlight the evolution of polymeric materials and mainly the current state of the art of the unique properties of some polymeric systems used for IOL design, identifying current limitations for future improvements. We investigate the characteristics of the next generation of IOL materials, which must satisfy biocompatibility requirements and have tuneable refractive index to create patient-specific eye power, preventing formation of posterior capsular opacification. [ABSTRACT FROM AUTHOR]

Traditional pharmacotherapy suffers from multiple drawbacks that hamper patient treatment such as antibiotic resistances or low drug selectivity and toxicity during systemic applications. Some functional hybrid nanomaterials are designed to handle the drug release process under remote-control. More attention has recently been paid to synthetic polyelectrolytes for their intrinsic properties which allow them to rearrange into compact structures, ideal to be used as drug carriers or probes influencing biochemical processes. The presence of Ag nanoparticles (NPs) in the Poly methyl acrylate (PMA) matrix leads to an enhancement of drug release efficiency, even using a low-power laser whose wavelength is far from the Ag Surface Plasmon Resonance (SPR) peak. Further, compared to the colloids, the nanofiber-based drug delivery system has shown shorter response time and more precise control over the release rate. The efficiency and timing of involved drug release mechanisms has been estimated by the Weibull distribution function, whose parameters indicate that the release mechanism of nanofibers obeys Fick's first law while a non-Fickian character controlled by diffusion and relaxation of polymer chains occurs in the colloidal phase. [ABSTRACT FROM AUTHOR]

Adaptive optics (AO) is employed for the continuous measurement and correction of ocular aberrations. Human eye refractive errors (lower-order aberrations such as myopia and astigmatism) are corrected with contact lenses and excimer laser surgery. Under twilight vision conditions, when the pupil of the human eye dilates to 5–7 mm in diameter, higher-order aberrations affect the visual acuity. The combined use of wavefront (WF) technology and AO systems allows the pre-operative evaluation of refractive surgical procedures to compensate for the higher-order optical aberrations of the human eye, guiding the surgeon in choosing the procedure parameters. Here, we report a brief history of AO, starting from the description of the Shack–Hartmann method, which allowed the first in vivo measurement of the eye's wave aberration, the wavefront sensing technologies (WSTs), and their principles. Then, the limitations of the ocular wavefront ascribed to the IOL polymeric materials and design, as well as future perspectives on improving patient vision quality and meeting clinical requests, are described. [ABSTRACT FROM AUTHOR]

The two-exponential Sheffield equation of viscosity η(T) = A1·T·[1 + A2·exp(Hm/RT)]·[1 + C·exp(Hd/RT)], where A1, A2, Hm, C, and Hm are material-specific constants, is used to analyze the viscous flows of two glass-forming organic materials—salol and α-phenyl-o-cresol. It is demonstrated that the viscosity equation can be simplified to a four-parameter version: η(T) = A·T·exp(Hm/RT)]·[1 + C·exp(Hd/RT)]. The Sheffield model gives a correct description of viscosity, with two exact Arrhenius-type asymptotes below and above the glass transition temperature, whereas near the Tg it gives practically the same results as well-known and widely used viscosity equations. It is revealed that the constants of the Sheffield equation are not universal for all temperature ranges and may need to be updated for very high temperatures, where changes occur in melt properties leading to modifications of A and Hm for both salol and α-phenyl-o-cresol. [ABSTRACT FROM AUTHOR]

Silver (Ag)-grafted PMA (poly-methacrylic acid, sodium salt) nanocomposite loaded with sorafenib tosylate (SFT), an anticancer drug, showed good capability as a drug carrier allowing on-demand control of the dose, timing and duration of the drug release by laser irradiation stimuli. In this study, the preparation of Ag-PMA capsules loaded with SFT by using sacrificial silica microparticles as templates was reported. A high drug loading (DL%) of ∼13% and encapsulation efficiency (EE%) of about 76% were obtained. The photo-release profiles were regulated via the adjustment of light wavelength and power intensity. A significant improvement of SFT release (14% vs. 21%) by comparing SFT-Ag-PMA capsules with Ag-PMA colloids under the same experimental conditions was observed. Moreover, an increase of drug release by up to 35% was reached by tuning the laser irradiation wavelength near to Ag nanoparticles' surface plasmon resonance (SPR). These experimental results together with more economical use of the active component suggest the potentiality of SFT-Ag-PMA capsules as a smart drug delivery system. [ABSTRACT FROM AUTHOR]

The aim of this research is the identification of main and common physical-chemical parameters which induce paper degradation. A simple protocol to monitor the quality and molecular structure of ancient papers under natural degradation processes was proposed. Two-dimensional micro-Raman mapping were carried out. Then, point to point, the changes of both the cellulose Raman signature and fluorescence signal intensity were analysed. Modern papers were artificially aged to simulate the natural degradation and a comparison with the trend found for the ancient paper was presented and discussed. Cellulose degradation involves different mechanisms such as dehydration, cleaving of cellulose-glycosidic bonds and glucopyranose rings oxidation, that induce a reduction in the polymerization degree. As shown by the changes of Raman and fluorescence signals and NMR relaxation times, the rate of each processes depends on the initial amount of glycosidic bonds in the cellulose amorphous and crystalline regions, respectively. All these informations are useful both to define procedures to restore old documents and also to preserve the quality of modern papers for a long-term time. Image 1 • Paper aging monitoring by the two-dimensional micro-Raman spectroscopy • Time-dependent paper degradation in relation to oxidative and hydrolytic mechanisms • Exponential behaviour of fluorescence as a function of aging days [ABSTRACT FROM AUTHOR]

High-performance hydrogen sulfide (H2S) sensors are mandatory for many industrial applications. However, the development of H2S sensors still remains a challenge for researchers. In this work, we report the study of a TiO2-based conductometric sensor for H2S monitoring at low concentrations. TiO2 samples were first synthesized using the sol-gel route, annealed at different temperatures (400 and 600 °C), and thoroughly characterized to evaluate their morphological and microstructural properties. Scanning electronic microscopy, Raman scattering, X-ray diffraction, and FTIR spectroscopy have demonstrated the formation of clusters of pure anatase in the TiO2 phase. Increasing the calcination temperature to 600 °C enhanced TiO2 crystallinity and particle size (from 11 nm to 51 nm), accompanied by the transition to the rutile phase and a slight decrease in band gap (3.31 eV for 400 °C to 3.26 eV for 600 °C). Sensing tests demonstrate that TiO2 annealed at 400 °C displays good performances (sensor response Ra/Rg of ~3.3 at 2.5 ppm and fast response/recovery of 8 and 23 s, respectively) for the detection of H2S at low concentrations in air. [ABSTRACT FROM AUTHOR]

The hydrogen density of states (DOS) in confined water has been probed by inelastic neutron scattering spectra in a wide range of its P–T phase diagram. The liquid–liquid transition and the dynamical crossover from the fragile (super-Arrhenius) to strong (Arrhenius) glass forming behavior have been studied, by taking into account the system polymorphism in both the liquid and amorphous solid phases. The interest is focused in the low energy region of the DOS ( E < 10 meV) and the data are discussed in terms of the energy landscape (local minima of the potential energy) approach. In this latest research, we consider a unit scale energy (EC) linked to the water local order governed by the hydrogen bonding (HB). All the measured spectra, scaled according to such energy, evidence a universal power law behavior with different exponents (γ) in the strong and fragile glass forming regions, respectively. In the first case, the DOS data obey the Debye squared-frequency law, whereas, in the second one, we obtain a value predicted in terms of the mode-coupling theory (MCT) ( γ ≃ 1.6 ). [ABSTRACT FROM AUTHOR]

The "dynamic" or "glass" transition in biomolecules is as important to their functioning as the folding process. This transition occurs in the low temperature regime and has been related to the onset of biochemical activity that is dependent on the hydration level. This protein transition is believed to be triggered by the strong hydrogen bond coupling in the hydration water. We study the vibrational bending mode and measure it using Fourier Transform Infrared spectroscopy. We demonstrate that at the molecular level the hydration water bending mode bonds the C=O and N-H peptide groups, and find that the temperature of the "dynamic" protein transition is the same as the fragile-to-strong dynamic transition in confined water. The fragile-to-strong dynamic transition in water governs the nature of the H bonds between water and peptides and appears to be universal in supercooled glassforming liquids. [ABSTRACT FROM AUTHOR]

Abstract Neurodegenerative diseases such as Alzheimer's are characterized by neuritic plaques throughout the brain gray matter, associated with neurofibrillary tangles and neuron loss. These plaques are formed by abnormal aggregation of amyloid beta (A β) peptide into insoluble fibrils. In the present work we study the A β 1 − 40 peptide in the three aggregations states – monomers, oligomers and fibrils – via small angle neutron scattering (SANS) technique. The size of the three forms as well as their fractal nature are investigated at physiologic conditions. Our results evidence that the A β 1 − 40 peptide has a good aggregation capability but can also adopt an unfolded conformation in particular conditions, as for example, when incubated in DMSO. Highlights • The size of the three forms of amyloid beta peptides as well as their fractal nature are measured at physiologic conditions. • Small Angle Neutron Scattering allows to clearly distinguish monomer, oligomer and fibril preparations. • Open and compact structures of the peptide are detected, that correspond to the monomeric and fibril states. [ABSTRACT FROM AUTHOR]

The development of novel nanomaterials as highly efficient gas-sensing materials is envisaged as one of the most important routes in the field of gas-sensing research. However, developing stable, selective, and efficient materials for these purposes is a highly challenging task requiring numerous design attempts. In this work, a ZrO2/Co3O4 composite is reported, for the first time, as a gas-sensing material for the detection of ethanol. The sensitive and selective detection of ethanol gas at 200 °C has been demonstrated for the ZrO2/Co3O4 (0.20 wt%/0.20 wt%)-based sensor. Furthermore, the sensor showed a very low response/recovery time of 56 s and 363 s, respectively, in response to a pulse of 20 ppm of ethanol and good stability. The interesting gas-sensing property of ZrO2/Co3O4 can be ascribed to both the porous structure, which facilitates the interaction between the target gas and the sensing site, and the p–p-junction-induced built-in electric field. These results indicate that the ZrO2/Co3O4 composite can serve as a heterostructured nanomaterial for the detection of ethanol gas. [ABSTRACT FROM AUTHOR]

The thermal properties of an extra Virgin Olive Oil (eVOO) depend on its composition and indeed characterize its quality. Many studies have shown that the freezing and melting behaviors of eVOOs can serve for geographical or chemical discrimination. We use Nuclear Magnetic Resonance spectroscopy to study the evolution of the fatty acids bands as a function of temperature during freezing and melting processes. In such a way we can follow separately the variations in the thermal properties of the different molecular groups during these thermodynamic phase transitions. The data indicate that the methyl group which is at the end of every fatty chain displays the major changes during both freezing and melting processes. [ABSTRACT FROM AUTHOR]

The thermal properties of many organic extra Virgin Olive Oils (eVOOs) coming from different countries of the world were investigated by Differential Scanning Calorimetry (DSC). This technique, through a series of heating and cooling cycles, provides a specific curve, i.e., a thermogram, which represents the fingerprint of each eVOO sample. In fact, variations due to the different cultivars, geographical origin or chemical composition can be highlighted because they produce changes in the corresponding thermogram. In particular, in this work, we show the results of an unsupervised multivariate statistical analysis applied to the DSC thermograms of many organic eVOOs. This analysis allows us to discriminate the geographical origin of the different studied samples in terms of the peculiar features shown by the melting profiles of the triacylglycerol moieties. [ABSTRACT FROM AUTHOR]

• A new magnetic nanoparticles of magnetite functionalized Schiff base modified nanocellulose [(pH-PDA-DANC)@Fe 3 O 4 NPs] was synthesized by an ecofriendly and a simple protocol. • The synthesized product was characterized using FTIR, XRD, SEM-EDX, and TGA analysis. • The magnetic nano-catalyst [(pH-PDA-DANC)@Fe 3 O 4 NPs] was used subsequently as a catalyst in the green and efficient procedure for one-pot multicomponent syntheses of imidazole derivatives. In the present work, a nanocellulose based magnetic nanocomposite [(pH-PDA-DANC)@Fe 3 O 4 NPs] was synthesized by an ecofriendly and a simple protocol and characterized by means of different techniques such as Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) equipped with an Energy Dispersive X-ray (EDX) probe and the Value Stream Mapping (VSM). The theoretical study of [(pH-PDA-DANC)@Fe 3 O 4 NPs] was investigated using Density Functional Theory (DFT) at the DFT-D3/ B3LYP/LanL2DZ level of theory to explore the nature of the interactions between the (pH-PDA-DANC) ligand and magnetite nanoparticles. The results indicate that the Fe 3 O 4 nanoparticles form covalent bonds with the N-ring of the ligand. Then, it was used as a catalyst in the green and efficient procedure for one-pot multicomponent syntheses of imidazole derivatives by the condensation of benzil or 9.10-phenanthrenequinone, benzaldehyde derivatives and ammonium acetate. The catalytic reaction provided the synthesis of above imidazole derivatives with high reaction efficiency (80 %-98.1 %) in a short reaction time (3 h) and in presence of a minimum amount of ethanol. The identification and structure of imidazole derivatives was determined analyzing the 1H NMR (Nuclear Magnetic Resonance) and FTIR spectra. This procedure has several advantages compared to the conventional method such as the high yields, short reaction times, easy separation of the nanocatayst from the reaction mixture by using a magnet, and the reusability of the catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

• A new magnetic nanoparticles of magnetite functionalized Schiff base modified nanocellulose [(pH-PDA-DANC)@Fe 3 O 4 NPs] was synthesized by an ecofriendly and a simple protocol. • The synthesized product was characterized using FTIR, XRD, SEM-EDX, and TGA analysis. • The magnetic nano-catalyst [(pH-PDA-DANC)@Fe 3 O 4 NPs] was used subsequently as a catalyst in the green and efficient procedure for one-pot multicomponent syntheses of imidazole derivatives. In the present work, a nanocellulose based magnetic nanocomposite [(pH-PDA-DANC)@Fe 3 O 4 NPs] was synthesized by an ecofriendly and a simple protocol and characterized by means of different techniques such as Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) equipped with an Energy Dispersive X-ray (EDX) probe and the Value Stream Mapping (VSM). The theoretical study of [(pH-PDA-DANC)@Fe 3 O 4 NPs] was investigated using Density Functional Theory (DFT) at the DFT-D3/ B3LYP/LanL2DZ level of theory to explore the nature of the interactions between the (pH-PDA-DANC) ligand and magnetite nanoparticles. The results indicate that the Fe 3 O 4 nanoparticles form covalent bonds with the N-ring of the ligand. Then, it was used as a catalyst in the green and efficient procedure for one-pot multicomponent syntheses of imidazole derivatives by the condensation of benzil or 9.10-phenanthrenequinone, benzaldehyde derivatives and ammonium acetate. The catalytic reaction provided the synthesis of above imidazole derivatives with high reaction efficiency (80 %-98.1 %) in a short reaction time (3 h) and in presence of a minimum amount of ethanol. The identification and structure of imidazole derivatives was determined analyzing the 1H NMR (Nuclear Magnetic Resonance) and FTIR spectra. This procedure has several advantages compared to the conventional method such as the high yields, short reaction times, easy separation of the nanocatayst from the reaction mixture by using a magnet, and the reusability of the catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

Gold nanoparticles (Au NPs) have received great attention owing to their biocompatible nature, environmental, and widespread biomedical applications. Au NPs are known as capable to regulate inflammatory responses in several tissues and organs; interestingly, lower toxicity in conjunction with anti-inflammatory effects was reported to occur with Au NPs treatment. Several variables drive this benefit-risk balance, including Au NPs physicochemical properties such as their morphology, surface chemistry, and charge. In our research we prepared hybrid Au@LCC nanocolloids by the Pulsed Laser Ablation, which emerged as a suitable chemically clean technique to produce ligand-free or functionalized nanomaterials, with tight control on their properties (product purity, crystal structure selectivity, particle size distribution). Here, for the first time to our knowledge, we have investigated the bioproperties of Au@LCCs. When tested in vitro on intestinal epithelial cells exposed to TNF- α , Au@LCCs sample at the ratio of 2.6:1 showed a significantly reduced TNF gene expression and induced antioxidant heme oxygenase-1 gene expression better than the 1:1 dispersion. Although deeper investigations are needed, these findings indicate that the functionalization with LCCs allows a better interaction of Au NPs with targets involved in the cell redox status and inflammatory signaling. [ABSTRACT FROM AUTHOR]