Polysaccharide-based biodegradable films for agricultural mulching

In the last 20 years, the global population has blowout growth from 6.0 billion to 7.2 billion and will reach over 8.0 billion around 2046 [1]. Consequently, food shortage has drawn attention, and the demand for agricultural products has increased annually. To meet this need, the excessive and prolonged use of mulching films based on low-density polyethene resulted in significant environmental pollution events, leading to serious side effects on human health [2]. Due to the thickness of the plastic film and the difficulty of recovery, some mulch films were discarded in agricultural soils intentionally or unintentionally. Mulch film residue is a direct source of farmland meso- and microplastics (MMPs), which constitute a global environmental issue, as they accumulate even in the food chain [3]. MMPs' further degradation into nanoscale particles can endanger human health [4]. To provide agricultural sustainability, there is a great interest in developing biodegradable bio-based polymeric films for agriculture mulching, which can be tilled directly into the soil after use. Based on the above issues, this study aims at (i) the preparation and characterisation of biodegradable bio-based composite films and (2) their enrichment with plant nutrients, which could be efficiently released into the water to sustain their application as mulch films on the soil. Sodium carboxymethyl cellulose (CMC), chitosan (CS) and sodium alginate (SA) were combined in the presence of glycerol as a plasticiser to produce composite films by solvent casting. Composition (i.e., concentrations and mass ratios between the precursors) and cross-linking agent (CaCl2) effects on films' properties were evaluated. In the first stage, we investigated the structure of the formed films through Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy, the thermal and mechanical properties by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA), and some water-interaction properties (degree of swelling and solubility in water). This approach allowed identifying the best quality films, which were enriched with NH4H2PO4, as N and P are generally the most deficient nutrients in the soil. Moreover, the release kinetics in the water of this salt was studied. The latter aspect is of great importance as the release of N and P helps to improve the nutrient supply to the soil, thus reducing the use of synthetic fertilisers. [1] B. Chieng et al. J. Appl. Polym. Sci. 130 (2013) 4576-4580 [2] H. M. S . Akhtar, et al. Int. J. Biol. Macromol. 118 (2018), 469-477 [3] M.C. Rillig, M. C. Environ. Sci. Technol. 46 (2012), 6453-6454 [4] I. Ali et al. J. Clean. Prod. 313 (2021) 12786

From micro to macro: Physical-chemical characterization of wheat starch-based films modified with PEG200, sodium citrate, or citric acid

Needing to extend the shelf-life of packaged food and the evolving consumer demands led researchers to seek innovative, eco-friendly, and biocompatible packaging solutions. Starch is among the most promising natural and renewable alternatives to non-degradable plastics. Here, we deeply study the structural features of starch films modified by adding citric acid (CA) or sodium citrate (SC) as a cross-linker and polyethylene glycol 200 (PEG200) as a plasticizer and obtained through solvent casting. The substances' influence on starch films was evaluated through Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) and Solid-state Nuclear Magnetic Resonance (ss-NMR) spectroscopies. Films' macroscopic properties, such as swelling index, solubility, thermo-mechanical features, and moisture absorption, were also assessed to foresee potential applications. Proper amounts of CA, CS, and PEG200 improve film properties and inhibit starch chains' retrogradation and recrystallization. Besides, the chemical neighbourhood of nuclei observed through ss-NMR significantly changed alongside the polymer chains' mobility. The latter result indicates a different polymer chain structural organization that could justify the film's higher resistance to thermal degradation and elongation at the break. This methodological approach is effective in predicting the macroscopic behaviour of a polymeric material and could be helpful for the application of such products in food preservation

Chemometric Tools to Point Out Benchmarks and Chromophores in Pigments through Spectroscopic Data Analyses

Spectral preprocessing data and chemometric tools are analytical methods widely applied in several scientific contexts i.e., in archaeometric applications. A systematic classification of natural powdered pigments of organic and inorganic nature through Principal Component Analysis with a multi-instruments spectroscopic study is presented here. The methodology allows the access to elementary and molecular unique benchmarks to guide and speed up the identification of an unknown pigment and its recipe. This study is conducted on a set of 48 powdered pigments and tested on a real-case sample from the wall painting in S. Maria Delle Palate di Tusa (Messina, Italy). Four spectroscopic techniques (X-ray Fluorescence, Raman, Attenuated Total Reflectance and Total Reflectance Infrared Spectroscopies) and six different spectrometers are tested to evaluate the impact of different setups. The novelty of the work is to use a systematic approach on this initial dataset using the entire spectroscopic energy range without any windows selection to solve problems linked with the manipulation of large analytes/materials to find an indistinct property of one or more spectral bands opening new frontiers in the dataset spectroscopic analyses

A New Methodological Approach to Correlate Protective and Microscopic Properties by Soft X-ray Microscopy and Solid State NMR Spectroscopy: The Case of Cusa’s Stone

Hydrophobic treatment is one of the most important interventions usually carried out for the conservation of stone artefacts and monuments. The study here reported aims to answer a general question about how two polymers confer different protective performance. Two fluorinated-based polymer formulates applied on samples of Cusa’s stone confer a different level of water repellence and water vapour permeability. The observed protection action is here explained on the basis of chemico-physical interactions. The distribution of the polymer in the pore network was investigated using scanning electron microscopy and X-ray microscopy. The interactions between the stone substrate and the protective agents were investigated by means of solid state NMR spectroscopy. The ss-NMR findings reveal no significant changes in the chemical neighbourhood of the observed nuclei of each protective agent when applied onto the stone surface and provide information on the changes in the organization and dynamics of the studied systems, as well as on the mobility of polymer chains. This allowed us to explain the different macroscopic behaviours provided by each protective agent to the stone substrate

Looking for the Original Materials and Evidence of Restoration at the Vault of the San Panfilo Church in Tornimparte (AQ)

This paper reports the investigation of six microsamples collected from the vault of the San Panfilo Church in Tornimparte (AQ). The aim was to detect the composition of the pigments and protective/varnishes, and to investigate the executive technique, the conservation state, and the evidence of the restoration works carried out in the past. Six microsamples were analyzed by optical microscopy, scanning electron microscopy coupled with energy-dispersive spectroscopy (EDS), X-ray fluorescence (XRF), and infrared and Raman spectroscopy. The investigations were carried out within the framework of the Tornimparte project “Archeometric investigation of the pictorial cycle of Saturnino Gatti in Tornimparte (AQ, Italy)” sponsored in 2021 by the Italian Association of Archeometry (AIAr)

Sicilian Byzantine Icons through the Use of Non-Invasive Imaging Techniques and Optical Spectroscopy: The Case of the <i>Madonna dell’Elemosina</i>

The iconographic heritage is one of the treasures of Byzantine art that have enriched the south of Italy, and Sicily in particular, since the early 16th century. In this work, the investigations of a Sicilian Icon of Greek-Byzantine origin, the Madonna dell’Elemosina, is reported for the first time. The study was carried out using mainly non-invasive imaging techniques (photography in reflectance and grazing visible light, UV fluorescence, infrared reflectography, radiography, and computed tomography) and spectroscopic techniques (X-ray fluorescence and infrared spectroscopy). The identification of the constituent materials provides a decisive contribution to the correct historical and artistic placement of the Icon, a treasure of the Eastern European historical community in Sicily. Some hidden details have also been highlighted. Most importantly, the information obtained enables us to define its conservation state, the presence of foreign materials, and to direct its protection and restoration

Diagnosis and treatment of Chiari malformation type 1 in children : the International Consensus Document

Chiari malformation type 1 (CM1) is a rare condition where agreed classification and treatment are still missing. The goal of this study is to achieve a consensus on the diagnosis and treatment of CM1 in children. A multidisciplinary panel formulated 57 provisional statements based on a review of the literature. Thirty-four international experts (IE) participated in a Delphi study by independently rating each statement on a 4-point Likert scale ("strongly disagree," "disagree," "agree," "strongly agree"). Statements that were endorsed ("agree" or "strongly agree") by < 75% of raters were re-formulated, or new statements were added, and another Delphi round followed (up to a maximum of three). Thirty-five IE were contacted and 34 agreed to participate. A consensus was reached on 30/57 statements (52.6%) after round 1. Three statements were added, and one removed. After round 2, agreement was reached on 56/59 statements (94.9%). Finally, after round 3, which took place during the 2019 Chiari Consensus Conference (Milan, Italy), agreement was reached on 58/59 statements (98.3%) about four main sections (Definition and Classification, Planning, Surgery, Isolated Syringomyelia). Only one statement did not gain a consensus, which is the "definition of radiological failure 24 month post-surgery." The consensus document consists of 58 statements (24 on diagnosis, 34 on treatment), serving clinicians and researchers following children with CM1. There is a clear need for establishing an international network and registry and to promote collaborative studies to increase the evidence base and optimize the long-term care of this patient populatio