113 research outputs found
Hydrolyzed protein based materials for biodegradable spray mulching coatings
Low density polyethylene (LDPE) films are widespread used in agriculture
for soil mulching. The use of LDPE mulching films causes the serious drawback of
huge quantities of waste to be disposed of. Over the last years the growing
environmental awareness has been prompting the research to develop a new
generation of mulching products starting with raw materials from renewable origin.
These materials have to retain their physical and mechanical properties while in use
and have to be compostable or biodegradable at the end of their life, degrading via
micro-organisms into carbon dioxide or methane, water and biomass. The research
is focused on the development of novel biodegradable polymeric materials based on
hydrolyzed proteins, derived from waste products of the leather industry.
Biodegradable soil mulching coatings were realized with these biodegradable
polymeric materials by means of spray techniques; the coatings were tested in a
Ligustrum ovalifolium cultivation carried out inside a greenhouse. This paper
describes the functionalities of the new bio-based mulching coatings, which were
developed and tested in real scale greenhouse cultivation tests. During the trial, the
biodegradable soil mulching materials showed suitable properties for an efficient
and profitable use in agriculture. The innovative biodegradable spray coatings
lasted up to 18 months. The biodegradable materials could be the environmentally
friendly alternatives to synthetic petro-chemical polymers and could contribute to a
sustainable agriculture
Ultrastructural and biochemical characterization of mechanically adaptable collagenous structures in the edible sea urchin Paracentrotus lividus
The viscoelastic properties of vertebrate connective tissues rarely undergo significant changes withinphysiological timescales, the only major exception being the reversible destiffening of the mammalianuterine cervix at the end of pregnancy. In contrast to this, the connective tissues of echinoderms (seaurchins, starfish, sea cucumbers, etc.) can switch reversibly between stiff and compliant conditions intimescales of around a second to minutes. Elucidation of the molecular mechanism underlying suchmutability has implications for the zoological, ecological and evolutionary field. Important informationcould also arise for veterinary and biomedical sciences, particularly regarding the pathological plasti-cization or stiffening of connective tissue structures. In the present investigation we analyzed aspectsof the ultrastructure and biochemistry in two representative models, the compass depressor ligamentand the peristomial membrane of the edible sea urchin Paracentrotus lividus, compared in three differentmechanical states. The results provide further evidence that the mechanical adaptability of echinodermconnective tissues does not necessarily imply changes in the collagen fibrils themselves. The higher gly-cosaminoglycan (GAG) content registered in the peristomial membrane with respect to the compassdepressor ligament suggests a diverse role of these molecules in the two mutable collagenous tissues.The possible involvement of GAG in the mutability phenomenon will need further clarification. Duringthe shift from a compliant to a standard condition, significant changes in GAG content were detected onlyin the compass depressor ligament. Similarities in terms of ultrastructure (collagen fibrillar assembling)and biochemistry (two alpha chains) were found between the two models and mammalian collagen.Nevertheless, differences in collagen immunoreactivity, alpha chain migration on SDS-PAGE and BLASTalignment highlighted the uniqueness of sea urchin collagen with respect to mammalian collagen
Gli echinodermi come modelli per lo studio di Distruttori Endocrini: un approccio integrato
Gli echinodermi rappresentano dei validi modelli sperimentali nell\u2019ambito dell\u2019ecotossicologia marina. Essi infatti sono organismi bentonici a diretto contatto con potenziali fonti di xenobiotici e offrono un ampio range di processi biologici utili per questo tipo di approccio. In questo lavoro sono presentati i risultati pi\uf9 significativi ottenuti nel nostro laboratorio utilizzando questi organismi come modelli per lo studio degli effetti di potenziali Distruttori Endocrini (ED). Sono stati presi in esame due diverse specie di echinodermi, il riccio di mare Paracentrotus lividus e il crinoide Antedon mediterranea, e due diversi aspetti della loro fisiologia, la biologia riproduttiva e lo sviluppo rigenerativo, rispettivamente. Esemplari adulti di entrambe le specie sono stati esposti a diversi ED, potenzialmente in grado di interferire con gli ormoni sessuali. Le concentrazioni utilizzate erano comparabili a quelle ambientali. La ricerca si \ue8 basata su un approccio multidisciplinare che ha previsto analisi morfologiche, chimiche e biochimiche. I risultati ottenuti hanno evidenziato la capacit\ue0 di questi composti di interferire con diversi parametri quali la crescita rigenerativa, il pattern istologico e il diametro delle uova prodotte, sebbene lo specifico meccanismo d\u2019azione sia ancora da chiarire. Infatti, nel caso di P. lividus, la somministrazione diretta di ormoni sessuali, quali l\u2019estradiolo, non produce effetti significativi sulla biologia riproduttiva dell\u2019animale. Nel complesso i risultati ottenuti sottolineano sia l\u2019importanza di utilizzare modelli alternativi nei test ecotossicologici sia la necessit\ue0 di approfondire maggiormente la fisiologia di base degli organismi modello
Effects of aircraft noise on annoyance, sleep disorders, and blood pressure among adult residents near the Orio al Serio International Airport (BGY), Italy
Introduzione: Il rumore aeroportuale pu\uf2 causare effetti extra-uditivi quali annoyance, disturbi del sonno, ipertensione, patologie cardiovascolari e alterazioni delle abilit\ue0 cognitive nei bambini. Obiettivi: Condurre un\u2019indagine trasversale tra gli adulti residenti in prossimit\ue0 dell\u2019Aeroporto Internazionale di Orio al Serio (BGY), per studiare l\u2019associazione tra rumore aeroportuale, annoyance, disturbi del sonno, pressione arteriosa e ipertensione. Metodi: Soggetti di et\ue0 45-70 anni sono stati suddivisi, sulla base della residenza, in tre zone acustiche di rumore aeroportuale: <60 (Riferimento), 60-65 (Zona
A) e 65-75 dBA (Zona B). Un campione di soggetti \ue8 stato invitato a sottoporsi a intervista e misurazioni della
pressione arteriosa. Per analizzare variabili quantitative e categoriche, sono stati utilizzati modelli di regressione
lineare multipla e di Poisson robusta, rispettivamente. Risultati: Tra giugno e settembre 2013 sono stati reclutati
400 soggetti (166 nella Zona di Riferimento, 164 nella Zona A e 70 nella Zona B). Rispetto al riferimento, sono
stati rilevati elevati punteggi di annoyance (diurni e notturni) nelle Zone A (+2,7) e B (+4,0) (p<0,001) e circa il
doppio di soggetti fortemente infastiditi in entrambe le zone (p<0,001). Anche i disturbi del sonno riferiti nel mese
precedente erano pi\uf9 frequenti nelle Zone A e B. I disturbi del sonno considerati complessivamente corrispondevano
a 19,9% nella Zona di Riferimento, 29,9% nella Zona A e 35,7% nella Zona B (p<0,001). Conclusioni: \uc8 stata
evidenziata una forte associazione tra rumore aeroportuale, annoyance e disturbi del sonno. Non \ue8 stata riscontrata
alcuna relazione con i livelli di pressione arteriosa e la prevalenza di ipertensione.Background: Aircraft noise may cause several non-auditory health effects, including annoyance, sleep disorders, hypertension, cardiovascular diseases, and impaired cognitive skills in children. Objectives: To perform a cross-sectional study among adult residents near the Orio al Serio International Airport (BGY), Italy to investigate the association between aircraft noise, annoyance, sleep disorders, blood pressure levels, and prevalence of hypertension. Methods: Residential addresses of subjects aged 45-70 years were geocoded and classified in three groups according to noise levels: <60 (Reference), 60-65 (Zone A), and 65-75 dBA (Zone B). A sample of subjects was invited to undergo a personal interview and blood pressure measurements. Multiple linear and robust Poisson regression models were used to analyze quantitative and categorical variables, respectively. Results: Between June and September 2013, we enrolled 400 subjects (166 in the Reference Zone, 164 in Zone A, and 70 in Zone B). Compared to the Reference Zone, we found elevated adjusted annoyance scores (day and night) in Zone A (+2.7) and Zone B (+4.0) (p<0.001) and about doubled proportions of severely annoyed subjects (p<0.001). Reported sleep disorders in the previous month were also more frequent in Zones A and B. Sleep disorders in general were 19.9% in the Reference Zone, 29.9% in Zone A, and 35.7% in Zone B (p<0.001). Conclusions: We found a strong association between aircraft noise levels, annoyance, and sleep disorders among adult residents near the Orio al Serio International Airport. We found no relationship with blood pressure levels and prevalence of hypertension
New insights into the mutable collagenous tissue of Paracentrotus lividus : preliminary results
The mechanically adaptable connective tissue of echinoderms (Mutable Collagenous Tissue\u2014MCT), which can undergo drastic nervously-mediated changes in mechanical properties, represents a promising model for biomaterial design and biomedical applications. MCT could be a source of, or an inspiration for, new composite materials whose molecular interactions
and structural conformation can be changed in response to external stimuli. MCT is composed mostly of collagen fibrils, comparable to those of mammals, plus a variety of other components, including other fibrillar structures, proteoglycans
and glycoproteins. This contribution presents the preliminary results of a detailed analysis of MCT components in the sea-urchin Paracentrotus lividus, focusing on biochemical characterization of the fibrils and biomolecular analysis of the presumptive glycoproteins involved. The final aims will be to confirm the presence and the role of these glycoproteins in echinoids and to manipulate simpler components in order to produce a composite with mutable mechanical properties
Mechanical properties of the compass depressors of the sea-urchin Paracentrotus lividus (Echinodermata, Echinoidea) and the effects of enzymes, neurotransmitters and synthetic tensilin-like protein
The compass depressors (CDs) of the sea-urchin lantern are ligaments consisting mainly of discontinuous collagen fibrils associated with a small population of myocytes. They are mutable collagenous structures, which can change their mechanical properties rapidly and reversibly under nervous control. The aims of this investigation were to characterise the baseline (i.e. unmanipulated) static mechanical properties of the CDs of Paracentrotus lividus by means of creep tests and incremental force-extension tests, and to determine the effects on their mechanical behaviour of a range of agents. Under constant load the CDs exhibited a three-phase creep curve, the mean coefficient of viscosity being 561±365 MPa.s. The stress-strain curve showed toe, linear and yield regions; the mean strain at the toe-linear inflection was 0.86±0.61; the mean Young's modulus was 18.62±10.30 MPa; and the mean tensile strength was 8.14±5.73 MPa. Hyaluronidase from Streptomyces hyalurolyticus had no effect on creep behaviour, whilst chondroitinase ABC prolonged primary creep but had no effect on secondary creep or on any force-extension parameters; it thus appears that neither hyaluronic acid nor sulphated glycosaminoglycans have an interfibrillar load transfer function in the CD. Acetylcholine, the muscarinic agonists arecoline and methacholine, and the nicotinic agonists nicotine and 1-[1-(3,4-dimethyl-phenyl)-ethyl]-piperazine produced an abrupt increase in CD viscosity; the CDs were not differentially sensitive to muscarinic or nicotinic agonists. CDs showed either no, or no consistent, response to adrenaline, L-glutamic acid, 5-hydroxytryptamine and γ-aminobutyric acid. Synthetic echinoid tensilin-like protein had a weak and inconsistent stiffening effect, indicating that, in contrast to holothurian tensilins, the echinoid molecule may not be involved in the regulation of collagenous tissue tensility. We compare in detail the mechanical behaviour of the CD with that of mammalian tendon and highlight its potential as a model system for investigating poorly understood aspects of the ontogeny and phylogeny of vertebrate collagenous tissues.(undefined)info:eu-repo/semantics/publishedVersio
Matrix metalloproteinases in a sea urchin ligament with adaptable mechanical properties
Mutable collagenous tissues (MCTs) of echinoderms show reversible changes in tensile properties (mutability) that are initiated and modulated by the nervous system via the activities of cells known as juxtaligamental cells. The molecular mechanism underpinning this mechanical adaptability has still to be elucidated. Adaptable connective tissues are also present in mammals, most notably in the uterine cervix, in which changes in stiffness result partly from changes in the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). There have been no attempts to assess the potential involvement of MMPs in the echinoderm mutability phenomenon, apart from studies dealing with a process whose relationship to the latter is uncertain. In this investigation we used the compass depressor ligaments (CDLs) of the sea-urchin Paracentrotus lividus. The effect of a synthetic MMP inhibitor - galardin - on the biomechanical properties of CDLs in different mechanical states ("standard", "compliant" and "stiff") was evaluated by dynamic mechanical analysis, and the presence of MMPs in normal and galardin-treated CDLs was determined semi-quantitatively by gelatin zymography. Galardin reversibly increased the stiffness and storage modulus of CDLs in all three states, although its effect was significantly lower in stiff than in standard or compliant CDLs. Gelatin zymography revealed a progressive increase in total gelatinolytic activity between the compliant, standard and stiff states, which was possibly due primarily to higher molecular weight components resulting from the inhibition and degradation of MMPs. Galardin caused no change in the gelatinolytic activity of stiff CDLs, a pronounced and statistically significant reduction in that of standard CDLs, and a pronounced, but not statistically significant, reduction in that of compliant CDLs. Our results provide evidence that MMPs may contribute to the variable tensility of the CDLs, in the light of which we provide an updated hypothesis for the regulatory mechanism controlling MCT mutability
New Insights into Mutable Collagenous Tissue: Correlations between the Microstructure and Mechanical State of a Sea-Urchin Ligament
The mutable collagenous tissue (MCT) of echinoderms has the ability to undergo rapid and reversible changes in passive mechanical properties that are initiated and modulated by the nervous system. Since the mechanism of MCT mutability is poorly understood, the aim of this work was to provide a detailed morphological analysis of a typical mutable collagenous structure in its different mechanical states. The model studied was the compass depressor ligament (CDL) of a sea urchin (Paracentrotus lividus), which was characterized in different functional states mimicking MCT mutability. Transmission electron microscopy, histochemistry, cryo-scanning electron microscopy, focused ion beam/scanning electron microscopy, and field emission gun-environmental scanning electron microscopy were used to visualize CDLs at the micro- and nano-scales. This investigation has revealed previously unreported differences in both extracellular and cellular constituents, expanding the current knowledge of the relationship between the organization of the CDL and its mechanical state. Scanning electron microscopies in particular provided a three-dimensional overview of CDL architecture at the micro- and nano-scales, and clarified the micro-organization of the ECM components that are involved in mutability. Further evidence that the juxtaligamental cells are the effectors of these changes in mechanical properties was provided by a correlation between their cytology and the tensile state of the CDLs
Ultrastructural and biochemical characterization of mechanically adaptable collagenous structures in the edible sea urchin Paracentrotus lividus
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