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We present a new method to synthesize bulk indium nitride by means of a simple solid-state chemical reaction carried out under hydrostatic high pressure/high temperature conditions in a multi-anvil apparatus, not involving gases or solvents during the process. The reaction occurs between the binary oxide $In_2O_3$ and the highly reactive $Li_3N$ as nitrogen source, in powder form. The formation of the hexagonal phase of InN, occurring at 350 {\deg}C and P $\geq$ 3 GPa, was successfully confirmed by powder X-ray diffraction, with the presence of $Li_2O$ as unique byproduct. A simple washing process in weak acidic solution followed by centrifugation, allowed to obtain pure InN polycrystalline powders as precipitate. With an analogous procedure it was possible to obtain pure bulk GaN, from $Ga_2O_3$ and $Li_3N$ at T $\geq$ 600{\deg}C and P $\geq$ 2.5 GPa. These results point out, particularly for InN, a clean, and innovative way to produce significant quantities of one of the most promising nitrides in the field of electronics and energy technologies., Comment: Under revision in a peer-review journal

Copper-doped antimony selenide (Cu-doped Sb2Se3) thin films were deposited as absorber layers in photovoltaic solar cells using the low-temperature pulsed electron deposition (LT-PED) technique, starting from Sb2Se3 targets where part of the Sb was replaced with Cu. From a crystalline point of view, the best results were achieved for thin films with about Sb1.75Cu0.25Se3 composition. In order to compare the results with those previously obtained on undoped thin films, Cu-doped Sb2Se3 films were deposited both on Mo- and Fluorine-doped Tin Oxide (FTO) substrates, which have different influences on the film crystallization and grain orientation. From the current-voltage analysis it was determined that the introduction of Cu in the Sb2Se3 absorber enhanced the open circuit voltage (VOC) up to remarkable values higher than 500 mV, while the free carrier density became two orders of magnitude higher than in pure Sb2Se3-based solar cells.

Multiferroics, showing the coexistence of two or more ferroic orderings at room temperature, could harness a revolution in multifunctional devices. However, most of the multiferroic compounds known to date are not magnetically and electrically ordered at ambient conditions, so the discovery of new materials is pivotal to allow the development of the field. In this work, we show that BaFe

Background The human taste experience is the result of five basic taste qualities, namely sweet, salty, bitter, sour and umami. Sweet, bitter, and umami are mediated by G protein-coupled receptors (GPCRs), whereas sour and salt are modulated by specialized membrane channels. Taste perception starts with the interaction between a taste-active molecule (substance) and a specialized receptor located on the taste buds at the level of the cell membrane. Once the interaction has occurred, taste receptor cells are able to transduce the information content of the chemical stimulus into nerve signals directly to the brain. Therefore, the receptor-mediated recognition of taste molecules is the first episode leading to taste perception. Scope and approach In this review, we provide a complete overview of in silico molecular modeling techniques applied to the study of umami, sweet, and bitter taste receptors. Structure-based computational tools, usually applied to investigate the binding mode of bioactive molecules into their targets and to rationally design new drug molecules, are proven equally useful in the field of chemical senses to shed light on the molecular acknowledgment of tastants. Key findings and conclusions The recent computational advancements in the taste research field, and particularly the computation-driven investigations of the tastant-receptor binding, provided a better understanding of the molecular mechanisms underlying food tastants’ sensing and could have an impressive contribution to the identification of new taste modulators in the future.

According to Eurostat, the EU production of chemicals hazardous to health reached 211 million tonnes in 2019. Thus, the possibility that some of these chemical compounds interact negatively with the human endocrine system has received, especially in the last decade, considerable attention from the scientific community. It is obvious that given the large number of chemical compounds it is impossible to use in vitro/in vivo tests for identifying all the possible toxic interactions of these chemicals and their metabolites. In addition, the poor availability of highly curated databases from which to retrieve and download the chemical, structure, and regulative information about all food contact chemicals has delayed the application of in silico methods. To overcome these problems, in this study we use robust computational approaches, based on a combination of highly curated databases and molecular docking, in order to screen all food contact chemicals against the nuclear receptor family in a cost and time-effective manner.

Background. Poisoning from pesticides can be extremely hazardous for non-invasive species, such as bees, and humans causing nearly 300,000 deaths worldwide every year. Several pesticides are recognized as endocrine disruptors compounds that alter the production of the normal hormones mainly by acting through their interaction with nuclear receptors (NRs). Among the insecticides, one of the most used is pyriproxyfen. As analogous to the juvenile hormone, the pyriproxyfen acts in the bee’s larval growth and creates malformations at the adult organism level. Methods. This work aims to investigate the possible negative effects of pyriproxyfen and its metabolite, the 4′-OH-pyriproxyfen, on human and bee health. We particularly investigated the mechanism of binding of pyriproxyfen and its metabolite with ultraspiracle protein/ecdysone receptor (USP-EcR) dimer of A. mellifera and the relative heterodimer farnesoid X receptor/retinoid X receptor alpha (FXR-RXRα) of H. sapiens using molecular dynamic simulations. Results. The results revealed that pyriproxyfen and its metabolite, the 4′-OH- pyriproxyfen, stabilize each dimer and resulted in stronger binders than the natural ligands. Conclusion. We demonstrated the endocrine interference of two pesticides and explained their possible mechanism of action. Furthermore, in vitro studies should be carried out to evaluate the biological effects of pyriproxyfen and its metabolite.

The umami taste receptor is a heterodimer composed of two members of the T1R taste receptor family: T1R1 (taste receptor type 1 member 1) and T1R3 (taste receptor type 1 member 3). Taste receptor T1R1-T1R3 can be activated, or modulated, by binding to several natural ligands, such as L-glutamate, inosine-5'-monophosphate (IMP), and guanosine-5'-monophosphate (GMP). Because no structure of the umami taste receptor has been solved until now, in silico techniques, such as homology modelling, molecular docking, and molecular dynamics (MD) simulations, are used to generate a 3D structure model of this receptor and to understand its molecular mechanisms. The purpose of this chapter is to highlight how computational methods can provide a better deciphering of the mechanisms of action of umami ligands in activating the umami taste receptors leading to advancements in the taste research field.

Risk-benefit assessment is the comparison of the risk of a situation to its related benefits, i.e. a comparison of scenarios estimating the overall health impact. The risk–benefit analysis paradigm mirrors the classical risk analysis one: risk–benefit assessment goes hand-in-hand with risk–benefit management and risk–benefit communication. The various health effects associated with food consumption, together with the increasing demand for advice on healthy and safe diets, have led to the development of different research disciplines in food safety and nutrition. In this sense, there is a clear need for a holistic approach, including and comparing all of the relevant health risks and benefits. The risk–benefit assessment of foods is a valuable approach to estimate the overall impact of food on health. It aims to assess together the negative and positive health effects associated with food intake by integrating chemical and microbiological risk assessment with risk and benefit assessment in food safety and nutrition. The 2019 Parma Summer School on risk–benefit in food safety and nutrition had the objective was to provide an opportunity to learn from experts in the field of risk–benefit approach in food safety and nutrition, including theory, case studies, and communication of risk–benefit assessments plus identify challenges for the future. It was evident that whereas tools and approaches have been developed, more and more case studies have been performed which can form an inherent validation of the risk–benefit approach. Executed risk–benefit assessment case studies apply the steps and characteristics developed: a problem formulation (with at least 2 scenarios), a tiered approach until a decision can be made, one common currency to describe both beneficial and adverse effects (DALYs in most instances). It was concluded that risk–benefit assessment in food safety and nutrition is gaining more and more momentum, while also many challenges remain for the future. Risk-benefit is on the verge of really enrolling into the risk assessment and risk analysis paradigm. The interaction between risk–benefit assessors and risk–benefit managers is pivotal in this, as is the interaction with risk–benefit communicators. Highlights: - Risk-benefit assessment goes hand-in-hand with RB-management and RB-communication; - Holistic approach in food safety and nutrition, comparing health risks and benefits; - Risk-benefit assessment estimates the overall impact of food on health; - Risk-benefit characteristics: problem formulation, tiered approach, common currency. info:eu-repo/semantics/publishedVersion

Humans, but also animals, are exposed to chemicals in everyday life. Many of these compounds are present in our food as food contact chemicals (FCCs), naturally occurring (toxins produced by plants), intentionally added (food additives, flavourings) or unintentionally added (pesticides, bisphenols, polychlorinated biphenyls). It is well-known that some of them can act as endocrine-disrupting chemicals (EDCs), which can interfere with the endocrine systems mainly by acting through their interaction with nuclear receptors (NRs). NRs are a superfamily constitute of 48 ligand-regulated transcription factors that are expressed in the animal kingdom and are essential for cell signalling, survival and proliferation. Thus, the alteration of nuclear receptor pathways is correlated to a large number of pathologies. Given the high number of EDCs we are exposed to, it is fundamental to test the endocrine disruptor properties of FCCs with alternative methods to animal testing. In this chapter, we focus our attention on the most common in vitro bioassays and in silico analysis as methods that can consider different endpoints of the NR pathway.

The umami taste receptor is a heterodimer composed of two members of the T1R taste receptor family: T1R1 (taste receptor type 1 member 1) and T1R3 (taste receptor type 1 member 3). Taste receptor T1R1-T1R3 can be activated, or modulated, by binding to several natural ligands, such as L-glutamate, inosine-5'-monophosphate (IMP), and guanosine-5'-monophosphate (GMP). Because no structure of the umami taste receptor has been solved until now, in silico techniques, such as homology modelling, molecular docking, and molecular dynamics (MD) simulations, are used to generate a 3D structure model of this receptor and to understand its molecular mechanisms. The purpose of this chapter is to highlight how computational methods can provide a better deciphering of the mechanisms of action of umami ligands in activating the umami taste receptors leading to advancements in the taste research field.

The application of computational methods (repository or database design, screening, and molecular docking) in food safety is a relatively recent challenge. Docking/scoring techniques could be applied to a wide range of food safety problems. An important milestone for screening/docking approaches is the availability of a three-dimensional database to collect the huge amount of food contact chemicals to make possible testing these compounds otherwise unfeasible with traditional in vitro tests. In silico applications could be applied to predict the interaction between food contact chemicals and different receptors/targets involved in human diseases and/or to decipher their mechanism of binding. Another important purpose is the design of chemosensors for mycotoxins detection. The use of docking techniques as an alternative to animal tests is an emerging field and we will illustrate these concepts using recently published cases.

We report on the high-pressure solid-state synthesis and the detailed structural characterization of the metastable, CuAu-type CuInS

We report on the high-pressure solid-state synthesis and the detailed structural characterization of the metastable, CuAu-type CuInS2 (CA-CIS) phase. Although often present in CIS thin films as unwanted phase, it has been never synthesized in pure form, and its effect on the performance of CIS-based solar cells has been long debated. In this work, pure CA-CIS phase is synthesized in bulk polycrystalline form through a high-pressure-high-temperature solid-state reaction. Single-crystal X-rays diffraction reveals the formation of tetragonal CA-CIS (a = 3.9324(5), c = 5.4980(7) A) either in cation-ordered and disordered phase, pointing out the role of the pressure/temperature increase on the Cu/In ordering. The resistivity measurements performed on CA-CIS show low resistivity and a flat trend vs temperature and, in the case of the ordered phase, highlight a bad-metallic behavior, probably due to a high level of doping. These findings clearly rule out the possibility of a beneficial effect of this phase on the CIS-based thin film solar cells.

We report on the room temperature, simple and cheap preparation by mechano-synthesis of polycrystalline targets of complex sulphide semiconductors, namely CuInS (CIS), to be used for film deposition in physical vacuum techniques such as PLD, sputtering or LT-PED. The sulphur (S)-based targets usually require expensive high pressure equipment to compensate the high S vapour pressure; nevertheless they are indispensable for the deposition of high band-gap semiconductor materials. The comparison of CIS films grown by mechano-synthesis and by commercial targets demonstrates similar material quality, making the mechano-synthesis a viable solution in the fabrication of high band-gap, S-based targets of complex chalcogenides.

Mycotoxins are secondary metabolites produced by pathogenic fungi. They are found in a variety of different products, such as spices, cocoa, and cereals, and they can contaminate fields before and/or after harvest and during storage. Mycotoxins negatively impact human and animal health, causing a variety of adverse effects, ranging from acute poisoning to long-term effects. Given a large number of mycotoxins (currently more than 300 are known), it is impossible to use in vitro/in vivo methods to detect the potentially harmful effects to human health of all of these. To overcome this problem, this work aims to present a new robust computational approach, based on a combination of in silico and statistical methods, in order to screen a large number of molecules against the nuclear receptor family in a cost and time-effective manner and to discover the potential endocrine disruptor activity of mycotoxins. The results show that a high number of mycotoxins is predicted as a potential binder of nuclear receptors. In particular, ochratoxin A, zearalenone, α- and β-zearalenol, aflatoxin B1, and alternariol have been shown to be putative endocrine disruptors chemicals for nuclear receptors.

In this paper we report on the single stage deposition of CuInxGa1−xSe2 (CIGS)-based bifacial solar cells on glass coated with Fluorine-doped Tin Oxide (FTO) or Indium Tin Oxide (ITO) by single-stage low-temperature (250 °C) pulsed electron deposition (LTPED). We show that the mechanism of Sodium incorporation during the low-temperature deposition of CIGS on both FTO and ITO leads to the formation of a stable n+/p+ ohmic tunnel junction and photovoltaic efficiencies exceeding 14% can be obtained without any intentional bandgap grading of CIGS. The significant degradation of the cell fill factor with decreasing CIGS thickness is found to be related to the presence of craters left behind by micro-fragments of CIGS target, which are weakly incorporated in the film during the LTPED growth and removed during the subsequent process steps. Evidence is also presented that the low-temperature deposition of CIGS on ITO leads to the formation of a Ga-rich CIGS layer at the interface and to an unintentional compositional grading propagating towards the active region of the solar cells. The defects associated with this grading may be responsible for the loss in FF and Voc with respect to the cells deposited on FTO and Mo back contacts.

CuSb(S,Se)2 is emerging as an alternative absorber for thin film photovoltaics, for its intrinsic p-type conductivity, tunable energy bandgap (1.0÷1.6 eV), high absorption coefficient > 104 cm-1 and very low cost of the constituent elements. In this work, we studied the structural, compositional and electro-optical properties of CuSbSe2 (CASe) films grown by Low Temperature Pulsed Electron Deposition (LTPED), a developing technology in thin film photovoltaics. We proved that stoichiometric or Cu-poor CASe films can be obtained at low temperature (< 200 °C) from a stoichiometric target with no need for post-deposition treatments to adjust the stoichiometry. Solar cells based on Cu-poor and stoichiometric CASe absorbers exhibit a similar open circuit voltage (~290÷310 mV), while the JSC increases from ~3 mA/cm2 up to ~20 mA/cm2 as the Cu/Sb ratio increases from 0.55 to 0.95. A low FF ~40% still limits the performance of all the cells indicating that the standard architecture of thin film solar cells, currently used for CIGS and CdTe devices, need to be significantly reviewed. The results of the structural and optoelectrical characterization presented in this paper show that JSC, VOC and FF can all be improved as a result of the optimization of the device architecture. The best of the LTPED-grown CASe cells obtained so far, reached an efficiency of 3.8%, very close to the state of the art reported so far in literature.

We report on the fabrication and characterization of Cu(In,Ga)Se2 (CIGS)-based thin film bifacial solar cells using Al-doped ZnO (AZO) as cost-effective and non-toxic transparent back contact. We show that, by depositing both CIGS and AZO by Low Temperature Pulsed Electron Deposition at a maximum temperature of 250 °C, a good ohmic contact is formed between the two layers and good quality solar cells can be fabricated as a result. Photovoltaic efficiencies as high as 9.3% (front illumination), 5.1% (backside illumination) and 11.6% (bifacial illumination) have been obtained so far. These values are remarkably higher than those previously reported in the literature. We demonstrate that this improvement is ascribed to the low-temperature deposition process that avoids the formation of Ga2O3 at the CIGS/AZO interface and favours the formation of a low-resistivity contact in agreement with device simulations.