RESUMEN
The fate of black biodegradable mulch film (MF) based on starch and poly(butylene-adipate-co-terephthalate) (PBAT) in agricultural soil is investigated herein. Pristine (BIO-0) and UV-aged film samples (BIO-A192) were buried for 16 months at an experimental field in southern Italy. Visual, physical, chemical, morphological, and mechanical analyses were carried out before and after samples burial. Film residues in the form of macro- and microplastics in soil were analyzed at the end of the trial. Progressive deterioration of both pristine and UV-aged samples, with surface loss and alterations in mechanical properties, occurred from 42 days of burial. After 478 days, the apparent surface of BIO-0 and BIO-A192 films decreased by 57 % and 66 %, respectively. Burial determined a rapid depletion of starch from the polymeric blend, especially for the BIO-A192, while the degradation of the polyester phase was slower. Upon burial, an enrichment of aromatic moieties of PBAT in the film residues was observed, as well as microplastics release to soil. The analysis of the MF degradation products extracted from soil (0.006-0.008 % by mass in the soil samples) revealed the predominant presence of adipate moieties. After 478 days of burial, about 23 % and 17 % of the initial amount of BIO-0 and BIO-A192, respectively, were extracted from the soil. This comprehensive study underscores the complexity of biodegradation phenomena that involve the new generation of mulch films in the field. The different biodegradability of the polymeric components, the climate, and the soil conditions that did not strictly meet the parameters required for the standard test method devised for MFs, have significantly influenced their degradation rate. This finding further emphasizes the importance of implementing field experiments to accurately assess the real effects of biodegradable MFs on soil health and overall agroecosystem sustainability.
Asunto(s)
Agricultura , Biodegradación Ambiental , Poliésteres , Contaminantes del Suelo , Suelo , Contaminantes del Suelo/análisis , Suelo/química , Italia , Almidón/química , Plásticos Biodegradables , Microplásticos/análisisRESUMEN
Cardoon, Cynara cardunculus L. represents a biorefinery crop with a great potential in the bioplastic field. This work investigates the valorization of different cardoon components into high added value products, finally recombined into novel upgraded bioplastics. Bioprocesses for Polyhydroxybutyrate (PHB) and medium-chain-length Polyhydroxyalkanoates (mcl-PHA) production were set up starting from root inulin and seed oil respectively, highlighting the effect of process conditions on polymer properties. The ternary blend, in which the PHB polymer matrix was added with mcl-PHA and epoxidized cardoon oil, evidenced a synergic effect of both additives in modulating PHB structural and thermal properties, promoted by the physical interaction occurring among the components. This proof-of concept frames the paper in the holistic approach of circular economy applied to bioplastic production.
Asunto(s)
Cynara , Polihidroxialcanoatos , Biomasa , Biopolímeros , Inulina , Aceites de PlantasRESUMEN
Musculoskeletal disorders are common in subjects with type 2 diabetes mellitus (T2DM) and may represent a barrier to physical activity (PA). In the Italian Diabetes and Exercise Study, we assessed whether a strategy aimed at minimizing the risk of injury and worsening of musculoskeletal symptoms favors participation in exercise training and results in improvements in joint-specific functional scores, along with amelioration of metabolic profile. Sedentary patients with T2DM (n = 606) from 22 outpatient diabetes clinics were randomized to twice-a-week supervised aerobic and resistance training plus exercise counseling (EXE) versus counseling alone (CON) for 12 months. Musculoskeletal symptoms were evaluated at baseline in the entire cohort by the use of a self-reported questionnaire in order to design tailored exercise programs with exclusion of painful segments, and validated joint-specific scores were calculated at the end of study in a subgroup of CON (n = 65) and EXE subjects (n = 62). Musculoskeletal symptoms were present in more than ¾ of EXE and CON subjects. Yet, volumes of non-supervised PA were high, whereas dropout rates and adverse events were low in both groups. Moreover, in the EXE group, no difference was observed between patients with and without symptoms in session attendance and PA/exercise volume. Scores for symptoms and functional status of limbs and spine were significantly better in EXE than in CON subjects and correlated with PA/exercise volume and improvements in fitness parameters. Preliminary evaluation of musculoskeletal symptoms is useful in favoring compliance with supervised training programs and obtaining significant benefits to the functional status of the involved joints.