A new mesophilous turkey oak woodland association from Laga Mts. (Central Italy).

The present paper aims at describing the Quercus cerris-dominated woodlands of the Laga mountains (central Apennines) in both the synecological and syntaxonomical way. Species composition and abundance, together with structural and abiotic parameters were recorded in 33 relevés distributed throughout the Laga massif. A new association of Quercus cerris woodlands, named Listero ovatae-Quercetum cerridis, is here proposed. The ecology and syn-chorology of this association are outlined. In syntaxonomical terms Listero-Quercetum cerridis behaves as an intermediate between Fagetalia sylvaticae and Quercetalia pubescenti-petraeae, being the dominant layer closer to Quercetalia communities and the herb layer to Fagetalia. For comparison a survey is provided of the most important Quercus cerris community types described throughout the whole Apennine chain using all published relevés (synoptic table)

A Simple Approach to Distinguish Classic and Formaldehyde-Free Tannin Based Rigid Foams by ATR FT-IR

Tannin based rigid foams (TBRFs) have been produced with formaldehyde since 1994. Only recently several methods have been developed in order to produce these foams without using formaldehyde. TBRFs with and without formaldehyde are visually indistinguishable; therefore a method for determining the differences between these foams had to be found. The attenuated total reflectance infrared spectroscopy (ATR FT-IR) investigation of the TBRFs presented in this paper allowed discrimination between the formaldehyde-containing (classic) and formaldehyde-free TBRFs. The spectra of the formaldehyde-free TBRFs, indeed, present decreased band intensity related to the C–O stretching vibration of (i) the methylol groups and (ii) the furanic rings. This evidence served to prove the chemical difference between the two TBRFs and explained the slightly higher mechanical properties measured for the classic TBRFs

Tannin- caprolactam and Tannin- PEG formulations as outdoor wood preservatives: Biological Properties

Key Message: This article presents the enhancement in boron fixation as well as the improved biological resistance against fungi and termites for wood samples treated with tannin-caprolactam and tannin-PEG formulations. Context: Although the recently developed tannin-boron wood preservatives have shown high biological protection, they presented also average resistance against weathering. The tannin-caprolactam formulations have shown improved weathering resistances and dimensional stability. Aims: For this reason, more detailed biological tests were performed to evaluate the influence of the caprolactam and PEG on the biological resistance. Methods: In this paper, the boron leaching of the tannin-caprolactam and tannin-PEG impregnated Scots pine specimens was observed and the biocidal effect against fungi (Antrodia spp. and Coniophora puteana) and insects (Reticulitermes flavipes and Hylotrupes bajulus) were determined according to the guidelines of EN 113, EN 117, and EN 47. Results: The advanced formulations containing PEG have shown interesting resistance against fungal decay, but very low penetration and weak resistance against larvae while the tannin-caprolactam preservatives have shown overall improved biological performances and higher boron fixations. Conclusion: The biocidal activity of the caprolactam-added formulations was overall enhanced and therefore these formulations are confirmed to be an interesting alternative for the wood preservation in outdoor environment. (Résumé d'auteur

Tannin- caprolactam and Tannin- PEG formulations as outdoor wood preservatives: Weathering properties

International audienceAbstractKey messageThis article presents the leaching, fire and weathering resistance improvements of samples treated with tannin-based wood preservatives added of caprolactam. PEG-added formulations show limited applicability. The FT-IR and13C-NMR analyses of the caprolactam-added formulations show some evidences of copolymerization.ContextTannin-boron wood preservatives are known for their high resistance against leaching, biological attacks, fire as well as for the good mechanical properties that they impart to wood. These properties promoted these formulations for being a candidate for the protection of green buildings. However, the low elasticity of these polymers and their dark colour implied limited weathering resistances.AimsThe aim of the study is to find suitable additives for tannin-based formulations to overcome their limited weathering resistances, without compromising the other properties.MethodsTreatment, leaching and fire tests, dimensional stability as well as artificial and natural weathering of the timber treated with caprolactam-added and PEG-added formulations were performed. FT-IR and 13C-NMR of the formulations were presented.ResultsThe presence of caprolactam improved the properties of the formulation with particularly significant results in terms of resistance against leaching and dimensional stability. These enhancements were imparted also to the weathering resistance of the tannin-caprolactam formulations. Indeed, the colour changes during the artificial and natural exposures were stable for longer periods. FT-IR and 13C-NMR investigations of the advanced formulations were led, and covalent copolymerization of the caprolactam with the tannin-hexamine polymer was observed.ConclusionThe tannin formulations with caprolactam improved the durability of the wood specimens, while the PEG-tannin presented strong application drawbacks

Can We Exploit β-Lactamases Intrinsic Dynamics for Designing More Effective Inhibitors?

β-lactamases (BLs) represent the most frequent cause of antimicrobial resistance in Gram-negative bacteria. Despite the continuous efforts in the development of BL inhibitors (BLIs), new BLs able to hydrolyze the last developed antibiotics rapidly emerge. Moreover, the insurgence rate of effective mutations is far higher than the release of BLIs able to counteract them. This results in a shortage of antibiotics that is menacing the effective treating of infectious diseases. The situation is made even worse by the co-expression in bacteria of BLs with different mechanisms and hydrolysis spectra, and by the lack of inhibitors able to hit them all. Differently from other targets, BL flexibility has not been deeply exploited for drug design, possibly because of the small protein size, for their apparent rigidity and their high fold conservation. In this mini-review, we discuss the evidence for BL binding site dynamics being crucial for catalytic efficiency, mutation effect, and for the design of new inhibitors. Then, we report on identified allosteric sites in BLs and on possible allosteric inhibitors, as a strategy to overcome the frequent occurrence of mutations in BLs and the difficulty of competing efficaciously with substrates. Nevertheless, allosteric inhibitors could work synergistically with traditional inhibitors, increasing the chances of restoring bacterial susceptibility towards available antibiotics

Pollutant absorption as a possible end-of-life solution for polyphenolic polymers

Tannin- and lignin-furanic foams are natural porous materials that have attracted high interest in the scientific and industrial communities for their high thermal and fire-resistant properties. However, no interesting solutions have been proposed for the management of their end-life as yet. In this study, the phenolic-furanic powders derived from the foams were analyzed for their capacity to remove dierent pollutants like neutral, cationic, and anionic organic molecules from wastewater. It was observed that the macromolecules produced from initially bigger fractions were more suitable to remove methylene blue and sodium dodecyl sulfate (SDS) while contained absorptions were observed for riboflavin. Acidified tannin powders were also prepared to understand the role of the flavonoid in the absorption mechanism. The latter showed outstanding absorption capacity against all of the tested pollutants, highlighting the key-role of the flavonoid fraction and suggesting the limited contribution of the furanic part. All adsorbents were investigated through FT-IR and solid state 13C-NMR. Finally, the powders were successfully regenerated by simple ethanol washing, showing almost complete absorption recovery

An analysis of the first-arrival times picked on the DSS and wide-angle seismic section recorded in Italy since 1968

We performed an analysis of refraction data recorded in Italy since 1968 in the frame of the numerous deep seismic sounding and wide-angle reflection/refraction projects. The aims of this study are to construct a parametric database including the recording geometric information relative to each profile, the phase pickings and the results of some kinematic analyses performed on the data, and to define a reference 1D velocity model for the Italian territory from all the available refraction data. As concerns the first goal, for each seismic section we picked the P-wave first-arrival-times, evaluated the uncertainties of the arrival-times pickings and determined from each travel time-offset curve the 1D velocity model. The study was performed on 419 seismic sections. Picking was carried out manually by an algorithm which includes the computation of three picking functions and the picking- error estimation. For each of the travel time-offset curves a 1D velocity model has been calculated. Actually, the 1D velocity-depth functions were estimated in three different ways which assume: a constant velocitygradient model, a varying velocity-gradient model and a layered model. As regards the second objective of this work, a mean 1D velocity model for the Italian crust was defined and compared with those used for earthquake hypocentre locations and seismic tomographic studies by different institutions operating in the Italian area, to assess the significance of the model obtained. This model can be used in future works as input for a next joint tomographic inversion of active and passive seismic data