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Biochar properties are highly dependent on the feedstock type and operational conditions during thermochemical processing, in particular slow pyrolysis. To clarify this aspect, nine biochars were produced by pyrolyzing in a macro TGA at 400, 550, and 650 °C three different decorticated and chopped biomasses. The studied biomasses are representative of conifer (black pine) and deciduous (poplar and willow) woods. Biochar surface area, size, and shape of pores were investigated by means of nitrogen adsorption isotherm, Hg porosimetry, and electron microscopy. The results indicate that biochars with high surface area can be obtained at high temperature, especially starting from pine feedstock. Regarding porosity, micro-pores (1–10 nm) are not remarkably affected by the starting feedstocks, while macro-pores (> 10 nm) are strictly connected with the morphology of the starting wood. More than the surface area, we found a strong correlation between the chemical composition (elemental composition and FTIR) of the biochars and their retention and release capacity of ions (cation exchange capacity, CEC). The trend in the CEC, determined via coupled approach by spectrophotometric and ion chromatography, reveals that the increase in the processing temperature has the effect of reducing the number of functional groups able of exchanging the cations with the equilibrium solution. This work represents a step forward in the characterization of the char produced by pyrolysis of biomass thanks to the development of a multi-technique approach allowing to obtain a structure-property correlation of the biochars. Our results and experimental approach can help in the optimization of the parameters used in the preparation of these materials. [ABSTRACT FROM AUTHOR]

A new green and effective sonochemical liquid-phase exfoliation (LPE) is proposed wherein a flavonoid compound, catechin (CT), promotes the formation of conductive, redox‐active, water‐phase stable graphene nanoflakes (GF). To maximize the GF-CT redox activity, the CT concentration and sonication time have been studied, and the best performing nanomaterial-fraction selected. Physicochemical and electrochemical methods have been employed to characterize the morphological, structural, and electrochemical features of the GF-CT nanoflakes. The obtained GF intercalated with CT exhibits fully reversible electrochemistry (ΔEp = 28 mV, ipa/ipc = ⁓1) because of the catecholic adducts. GF-CT-integrated electrochemistry was generated directly during LPE of graphite, with no need of graphene oxide production, nor activation steps, electropolymerization, or ex-post functionalization. The GF-CT electro-mediator ability has been proven towards hydrazine (HY) and β-nicotinamide adenine dinucleotide (NADH) by simply drop-casting the redox-material onto screen-printed electrodes. GF-CT-based electrodes by using amperometry exhibited high sensitivity and extended linear ranges (HY: LOD = 0.1 µM, L.R. 0.5–150 µM; NADH: LOD = 0.6 µM, L.R. 2.5–200 µM) at low overpotential (+ 0.15 V) with no electrode fouling. The GF-CT electrodes are performing significantly better than commercial graphite electrodes and graphene nanoflakes exfoliated with a conventional surfactant, such as sodium cholate. Recoveries of 94–107% with RSD ≤ 8% (n = 3) for determination of HY and NADH in environmental and biological samples were achieved, proving the material functionality also in challenging analytical media. The presented GF-CT is a new functional redox-active material obtainable with a single-pot sustainable strategy, exhibiting standout properties particularly prone to (bio)sensors and cutting-edge device development. [ABSTRACT FROM AUTHOR]

Herein we report a facile approach to prepare low DS microfibrillated cellulose acetoacetates and esters. All the reactions were performed directly in cellulose slurries without the need of solvent evaporation, which can cause hornification, and without damaging the fibres. The products obtained display the inserted functionalities while retaining the main features and morphology of the unmodified cellulose fibres. In comparison to previously reported synthetic routes, this method is cost-effective, more environmentally friendly through omission of extra solvents and the possibility of reusing the dispersing agents, which can be recovered by distillation. [ABSTRACT FROM AUTHOR]

A high-performance screen-printed electrode (SPE) based nanocomposite sensor integrating tungsten disulfide (WS2) flakes decorated with catechin-capped gold nanoparticles (AuNP-CT) and carbon black (CB) has been developed. The excellent antifouling properties of WS2 decorated with AuNP-CT into a high conductivity network of CB results in high selectivity, sensitivity, and reproducibility for the simultaneous determination of hydroxycinnamic acid (hCN) structural analogs: caffeic (CF), sinapic (SP), and p-coumaric acids (CM). Using differential pulse voltammetry (DPV), the target hCNs resulted in three well-resolved oxidation peaks at SPE-CB-WS2/AuNP-CT sensor. Excellent antifouling performance (RSD ip,a ≤ 3%, n = 15 for three analytes' simultaneous measure) and low detection limits (CF 0.10 μmol L−1; SP, 0.40 μmol L−1; CM, 0.40 μmol L−1) are obtained despite the analyzed compounds having a high passivation tendency towards carbon-based sensors. The SPE-CB-WS2/AuNP-CT sensor was successfully applied to determine CF, SP, and CM in food samples with good precision (RSD ≤ 4%, n = 3) and recoveries (86–109%; RSD ≤ 5%, n = 3). The proposed sensor is the first example exploiting the simultaneous determination of these compounds in food samples. Given its excellent electrochemical performance, low cost, disposability, and ease of use, this SPE-CB-WS2/AuNP-CT nanocomposite sensor represents a powerful candidate for the realization of electrochemical devices for the determination of (bio)compounds with high passivation tendency. [ABSTRACT FROM AUTHOR]

A polystyrene ELISA plate (EP) modified with a thin film based on gold nanoseeds (AuSDs) assembled onto polydopamine (PDA) is proposed. The nanodecorated film (PDA@AuSD) allows to evaluate the polyphenols antioxidant capacity (AOC) through a colorimetric approach based on a seed-mediated growth strategy. Polyphenols, in the presence of the nanodecorated (PDA@AuSD) surfaces are able to drive an increase in size of the AuSDs according to their AOC; this produces an increase of the localized surface plasmon resonance (LSPR; maximum at λ ~ 550 nm) that is taken as analytical signal. The PDA@AuSD EP manufacturing shows good intraplates repeatability (RSD ≤ 6.6%, n = 96 wells) and interplates reproducibility (RSD ≤ 7.4%, n = 748 wells), resulting stable for 1 year. The AuSDs growth kinetic has been studied using 11 polyphenols belonging to different chemical classes and 4 different food samples. The PDA@AuSD film is able to return quantitative information on the AOC of food polyphenols. Good repeatability (RSD ≤ 5.7%, n = 12 EP wells) and reproducibility (RSD ≤ 8.1%, n = 12 EP wells) was achieved, with acceptable linear correlation coefficients (R2 ≥ 0.990) and useful limits of detection (LODs ≤ 2.5 10−5 mol L−1). The samples analyzed with the PDA@AuSD device have been successfully ordered according to their AOC in agreement with conventional optical methods. The PDA@AuSD plate allows multiple measurements (96 wells per EP) with a one-step strategy, overcoming the limitations related to the use of colloidal nanoparticles; in addition, since absorbance is measured after washing, it is not affected by sample color or turbidity. [ABSTRACT FROM AUTHOR]

Several studies have demonstrated high polyamine levels in brain diseases such as epilepsy. Epilepsy is the fourth most common neurological disorder and affects people of all ages. Excitotoxic stress has been associated with epilepsy and it is considered one of the main causes of neuronal degeneration and death. The transgenic mouse line Dach-SMOX, with CD1 background, specifically overexpressing spermine oxidase in brain cortex, has been proven to be highly susceptible to epileptic seizures and excitotoxic stress induced by kainic acid. In this study, we analysed the effect of spermine oxidase over-expression in a different epileptic model, pentylenetetrazole. Behavioural evaluations of transgenic mice compared to controls showed a higher susceptibility towards pentylentetrazole. High-performance liquid chromatography analysis of transgenic brain from treated mice revealed altered polyamine content. Immunoistochemical analysis indicated a rise of 8-oxo-7,8-dihydro-2′-deoxyguanosine, demonstrating an increase in oxidative damage, and an augmentation of system xc− as a defence mechanism. This cascade of events can be initially linked to an increase in protein kinase C alpha, as shown by Western blot. This research points out the role of spermine oxidase, as a hydrogen peroxide producer, in the oxidative stress during epilepsy. Moreover, Dach-SMOX susceptibility demonstrated by two different epileptic models strongly indicates this transgenic mouse line as a potential animal model to study epilepsy. [ABSTRACT FROM AUTHOR]

Sensitive impedimetric detection of miR-222, a miRNA sequence found in many lung tumors, was investigated by using gold-nanostructured disposable carbon electrodes and enzyme-decorated liposomes. The proposed method was based on the immobilization of thiolated DNA capture probes onto gold-nanostructured carbon surfaces. Afterwards, the capture probes were allowed to hybridize to the target miRNAs. Finally, enzyme-decorated liposomes were used as labels to amplify the miRNA sensing, by their association with the probe-miRNA hybrids generated on the nanostructured transducer. By using this amplification route a limit of detection of 0.400 pM, a limit of quantification of 1.70 pM, and an assay range spanning three orders of magnitude (1.70-900 pM) were obtained (RSD % = 13). This limit of quantification was 20 times lower than that obtained using a simple enzyme conjugate for the detection. A comparison was also made with gold screen-printed transducers. In this case, a limit of quantification approximately 70 times lower was found by using the nanostructured transducers. Application of the optimized assay in serum samples was also demonstrated. [ABSTRACT FROM AUTHOR]

Gels are particularly useful for the cleaning of works of art, as they allow the controlled delivery of cleaning fluids on solvent-sensitive substrates such as easel paintings. Owing to the presence of covalent cross-links between the polymer chains, chemical gels exhibit mechanical properties that allow their easy handling and their residue-free removal from artistic surfaces after the cleaning intervention. Organogels based on the cross-linking of methyl methacrylate (MMA) can be prepared as loaded with solvents for the controlled removal of unwanted layers from the surface of canvas paintings. Here, we propose MMA-based organogels obtained by solubilizing MMA in pure organic solvents (e.g., ethyl acetate, butyl acetate and ketones) and using a dimethacrylate cross-linker. The uptake/release behavior of the gels has been investigated, and their mesoporosity has been characterized through small-angle X-ray scattering. Finally, the gels have been used for the removal of historical varnishes from canvas painting samples, checking the absence of gel residues with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). [ABSTRACT FROM AUTHOR]

The human deep space exploration focused on Mars, being the near eventual final destination. Mars surface habitation is considered a dangerous solution. Among others, radiation, micrometeorites and dust storms, are the major causes of risk for the human well-being during the mission. Caves on Mars can provide a natural shelter against these environmental hazards. Several practical applications address forward the use of caves as habitation opportunity. Within the caves, inflatable structures can be used, as opposed to the heavy structure surface buildings. For this reason, studies were taken to assess the possible areas for which caves could be used as human habitats as an alternative for an initial settlement of Mars. The results obtained not only suggest strong arguments for the use of caves, but also open questions for further quantification and understanding of current unknowns. In the present review, we focus on the hypothetical biological effects due to the cave shelter for natural background radiation that is of three orders of magnitude lower than Mars surface. Background radiation is the ubiquitous ionizing radiation that organisms experienced on the Earth, being present at the appearance of life on Earth. Nevertheless, both the effects of natural background radiation and its absence are not well known. We review the literature based on the effects of the absence of natural background to pursue a common scientific effort to gain scientific knowledge in this future deep space exploration scenario in a Sino-Italy cooperation, taking advantage of the JingPing cavern laboratory in the Sichuan region. [ABSTRACT FROM AUTHOR]

Skin reaction to irradiation is a key factor to understand the role of high-linear energy transfer radiation in the treatment of cancer, as well as the tolerance of the damage and the functional changes induced in the contiguous normal tissues. Moreover, low doses of neutron are a potentially dangerous hazard during low earth astronautic orbit missions and aircrew activities. To this purpose, mice skin irradiated with 14 Mev neutrons was studied in term of its genomic response combining cDNA microarrays methodology, to analyze transcriptomic changes, and high resolution Fourier transform-infra red (FT-IR) spectroscopy, to monitor the lipid content and distribution in dorsal skin sections after the neutron irradiation treatment. FT-IR spectroscopy imaging provides both spatial and biochemical information on a micrometric scale without being destructive, thus representing a novel and powerful approach in the context of revealing radiation exposure effects. [ABSTRACT FROM AUTHOR]

Low-dose exposure of ionizing radiation triggers cell-to-cell communications and tissue interplay alterations. These alterations may play a fundamental role in non-cancer effects, overwhelming the theory of the DNA centric approach. Neither the mechanisms of these effects are fully understood nor is it possible to dissect the real incidence of quality and quantity of incident radiation during in vivo exposure, overall for particulate high-linear energy transfer (LET) radiation. Moreover, the knowledge of particulate high-LET radiation is mandatory for the human deep space exploration and to gain efficiency in the dose/effect ratio for radiotherapy. The aim of this mini-review was to describe an integrated system approach to the radiation biology of cosmic interest which could be set up in the framework of a future Sino-Italy cooperation among participating laboratories. We propose, in particular, to deliver X-rays and neutron irradiation at ENEA-FNG (Frascati, Italy) and heavy ion irradiation at IMP-CAS (Lanzhou, China) to in vivo models. The integrated system approach will focus on the correlation between the quality and quantity of radiation exposure and its in vivo biological effects. Wide range molecular profiling will analyze mainly cell and DNA damages and cell-to-cell and tissues interplay, meanwhile biochemical and chemical specific composition will be detected by infrared spectroscopy. The recently characterized alteration of leptin metabolism is discussed in more detail to present a successful example of systemic approach to cosmic radiation biology. [ABSTRACT FROM AUTHOR]

Destruction of cells by irradiation-induced radical formation is one of the most frequent interventions in cancer therapy. An alternative to irradiation-induced radical formation is in principle drug-induced formation of radicals, and the formation of toxic metabolites by enzyme catalyzed reactions. Thus, combination therapy targeting polyamine metabolism could represent a promising strategy to fight hyper-proliferative disease. The aim of this work is to discuss and evaluate whether the presence of a DNA damage provoked by enzymatic ROS overproduction may act as an additive or adaptive response upon radiation and combination of hyperthermia with lysosomotropic compounds may improve the cytocidal effect of polyamines oxidation metabolites. Low level of X-irradiations delivers challenging dose of damage and an additive or adaptive response with the chronic damage induced by spermine oxidase overexpression depending on the deficiency of the DNA repair mechanisms. Since reactive oxygen species lead to membrane destabilization and cell death, we discuss the effects of BSAO and spermine association in multidrug resistant cells that resulted more sensitive to spermine metabolites than their wild-type counterparts, due to an increased mitochondrial activity. Since mammal spermine oxidase is differentially activated in a tissue specific manner, and cancer cells can differ in term of DNA repair capability, it could be of interest to open a scientific debate to use combinatory treatments to alter spermine metabolism and deliver differential response. [ABSTRACT FROM AUTHOR]

We study the evolution of the Boson peak for water confined in cement paste obtained by means of Inelastic Neutron Scattering from room temperature to the deep supercooled regime. We analyze the data in terms of a universal-like model, developed for glass forming liquids in the frame of the energy landscape. In such a way it is possible to discriminate between the fragile and strong glass forming character of supercooled liquids and the dynamical crossover, fragile to strong, between them. Hence, we confirm the link between the Boson peak and the water polymorphism. In particular, the main result is represented by a crossover from a local energetic minima configuration to that characteristic of saddle points on going towards the deep supercooled regime up to the dynamical arrest. [ABSTRACT FROM AUTHOR]

A new hybrid nanomaterial is used in a screen-printed electrode (SPE) for sensing of the ortho-diphenols oleuropein (OLEU) and hydroxytyrosol (HYT) in extra virgin olive oil (EVOO) and related samples. The hybrid material consists of carbon black (CB) and molybdenum disulfide (MoS2). In comparison with individual nanomaterials, CB-MoS2 exhibits improved charge-transfer ability, low charge-transfer resistance, high electrical conductivity and enhanced electrocatalysis. The sensor is also characterized by (a) high sensitivity that avoids the need for adsorptive voltammetry, (b) reduced analysis time, and (c) high anti-fouling ability (electrode RSDOLEU < 8%, for n = 10). OLEU can be detected in the 0.3 to 30 μM concentration range with a 0.1 μM LOD, and HYT in the 2–100 μM range with a 1 μM LOD. A comparison of the data obtained by this sensor and by HPLC-UV exhibited high correlation (r = 0.995, p < 0.05). These data revealed the reliability of CB-MoS2 for analysis of complex EVOO and related samples. [ABSTRACT FROM AUTHOR]