170,184 research outputs found
EMERGING ORGANIC CONTAMINANTS IN INTERIORS
No full textRecently, emerging contaminants (ECs) have gained the concern of environmental scientists. This class of toxicants is overall typical of indoor environments; aside of work places, interiors of dwellings, public buildings, offices and shopping centers are involved; there, people spend most of the life time (80-90% of the total). In interiors, ECs reach concentrations much higher than outdoors, giving raise to exposure rates up to thousands times higher. Even the way of toxicants’ intake changes; indeed, while at open air inhalation is predominant, indoors both ingestion and contact gain importance.
ECs display a wide variety of chemical properties and toxicity forms. Most EDs are organic displaying semi-volatile properties, occur in a number of healthcare and house products, in foods, furniture and building materials; usually EDs are not carcinogenic but promote allergies, immune depression, irritation and other acute effects, endocrine system damages, as well as chronic diseases like diabetes, infertility and psychologic problems. Among ECs, key roles are played by plasticizers (e.g., phthalates and adipates), flame retardants (PBDEs, organic phosphates),. Worth of note, EC chemicals occurring in ambient air and surfaces are distinct from those affecting waters (fluorinated surfactants, alkyl ethoxylates, drug by-products).
No attention is usually paid to psychotropic compounds (with illicit drugs) as well as to pharmaceuticals, analogously to cosmetics whose formulas include a list of anti-oxidants/UV light shields and additives (parabens, alkylphenols, bisphenols; fragrances and siloxanes) ascertained as harmful. Interestingly, these categories affect air in the native form, unlike waters, sewages and wastes, where they occur overall as degradation products [1]. Almost no investigations have been conducted till now and cumulative data bases are poor.
To improve the knowledge at this regards, an extensive study has been undertaken in Italy aimed at identifying a list of target substances (crossing toxic properties and environmental occurrence of ECs, with special focus on drugs and pharmaceuticals), at optimizing the sampling and chemical analysis procedures for both gaseous and particulate chemicals based on bench-top GC-MSD techniques), and at acquiring information about their loads and behaviours in interiors, through in-field measurements conducted at schools, dwellings, offices, labs and hospitals.
References
[1] A. Cecinato, P. Romagnoli, M. Perilli, C. Balducci. Environ. Sci. Pollut. Res., 2017, 35, 21256.
Tradizione manoscritta ippocratica e galeniana: incroci e contaminazione: il ruolo dei recentiores e lo stemma codicum del Glossario ippocratico (con un approfondimento sui Parisini Graeci 2140 e 2144)
No full textApplication of the digital volume correlation technique for the measurement of displacement and strain fields in bone: a literature review
No full textAbstract not availableBryant C. Roberts, Egon Perilli, Karen J. Reynold
Recensione di Beiträge zur antiken Philosophie: Festschrift für W. Kullmann, hrsg. von H.-C. Günther und A. Rengakos, Stuttgart, 1997
No full textNuovi manoscritti del Glossario Ippocratico di Galeno e considerazioni stemmatiche – Codex olim Mosquensis, codex Bodleianus Holkhamensis 92
No full textScrivere la medicina. La trascrizione dei miracoli di Asclepio e il Corpus Hippocraticum
No full textThe practice of medicine in ancient Greece and Near-Eastern countries was deeply related to the medium of writing in all of its forms - tablets, papyrus rolls, loose sheets -, and this had an impact not only on the preservation and circulation of scientific knowledge, but also on some chatacteristics of the texts of the so-called Hippocratic corpus
Test proiettivo della casa: approfondimento psicodinamico
No full textIl Disegno della Casa è una tecnica grafica proiettiva elaborata da John N. Buck nel 1948, parte costitutiva del più ampio test House-Tree-Person (H-T-P). Inizialmente proposto come sviluppo del Draw-a-man ideato da Florence Goo- denough nel 1926 (Roberti, 2015) come un indice di misurazione non verbale dell’intelligenza (Jolly, 2010), il test House-Tree-Person è stato elaborato e appro- fondito da Buck come strumento per la misurazione qualitativa e interpretativa di caratteristiche globali della personalità (Roberti, 2015), unendo il disegno della casa con quello dell’albero e della persona (Passi Tognazzo, 1975).
I presupposti teorici di questa tecnica si basano sul principio secondo cui le persone proiettano nel disegno aspetti del proprio mondo interiore. Il test House- Tree-Person, utilizzato con altri strumenti proiettivi verbali come il Rorschach e il TAT, non si sovrappone ad essi. Il disegno, infatti, canalizza principalmente i processi espressivi, a differenza delle prove verbali che canalizzano i processi re- attivi; inoltre sono i primi indicatori che mostrano segni di psicopatologia e gli ultimi a scomparire con il procedere della terapia; in questo modo il disegno risulta più sensibile alla psicopatologia rispetto ad altre tecniche proiettive, permette l’emergere di stati più profondi della personalità, fornendo un quadro generale da completare attraverso tecniche di indagine successive (Buck & Warren, 1992).
La valutazione del livello intellettivo si basa sulla capacità di generare e iden- tificare le informazioni elementari richieste per disegnare i dettagli, prendendo in considerazione l’organizzazione e la qualità dei disegni, una volta terminati. Tuttavia, la ricerca è risultata inconcludente riguardo le relazioni tra i disegni e il QI o altre sindromi (Buck & Warren, 1992)
Numerical modeling of F-.Actin bundles interacting with cell membranes
No full textActin is one of the most aboundant proteins in eukaryotic cells, where it forms a dendridic network (cytoskeleton) beneath the cell membrane providing mechanical stability and performing fundamental tasks in several functions, including cellular motility. The first step in cell locomotion is the protrusion of a leading edge, for which a significant deformation of the membrane is required: this step relies essentially on the forces generated by actin polymerization pushing the plasma membrane outward. Different types of structures can emerge from the plasma membrane, like lamellipodia (quasi-2d actin mesh) and filopodia (parallel actin bundles).
The main topic of the research project is the dynamics of bundles of parallel actin filaments growing against barriers, either rigid (a wall) or flexible (a membrane).
In the first part of the thesis, the dynamic behavior of bundles of actin filaments growing against a loaded wall is investigated through a generalized version of the standard multi filaments Brownian Ratchet model in which the (de)polymerizing filaments are treated not as rigid rods but as semi-flexible discrete wormlike chains with a realistic value of the persistence length.
A Statistical Mechanics framework is built for bundles of actin filaments growing in optical trap apparatus (harmonic external load) and several equilibrium properties are derived from it, like the maximum force that the filaments can exert (stalling force) or the number of filaments in contact with the wall.
Besides, Stochastic Dynamic simulations are employed to study the non-equilibrium relaxation of the bundle of filaments growing in the same optical trap apparatus, interpreting the system evolution by a suitable Markovian approach. Thanks to the observed time scale separation between the wall motion and the filament size relaxation, the optical trap set-up allows to extract the full velocity-load curve V(F) -- the velocity at which the obstacle moves when subject to the combined action of the polymerizing filaments and the external load F -- from a single experiment.
The main finding is the observation of a systematic evolution of steady non-equilibrium states over three regimes of bundle lengths L. A first threshold length Λ marks the transition between the rigid dynamic regime (L Λ), where the velocity V(F,L) is an increasing function of the bundle length L at fixed load F, the enhancement being the result of an improved level of work sharing among the filaments induced by flexibility. A second critical length corresponds to the beginning of an unstable regime characterized by a high probability to develop escaping filaments which start growing laterally and thus do not participate anymore to the generation of the polymerization force. This phenomenon prevents the bundle from reaching at this critical length the limit behavior corresponding to Perfect Load Sharing.
In the second part of the thesis, filaments growing against a flexible, deformable membrane are studied by means of Langevin dynamics simulations; the membrane is discretized into a dynamically triangulated network of tethered beads, while the filaments are described as chains of bonded monomers. Both the monomers in the filaments and the membrane beads, which interact with each other via a purely repulsive potential, are followed in space and time integrating its equations of motion with a second order accurate scheme. The elastic properties of the membrane are studied in detail via several methods, showing an unprecedentent level of agreement among them. The onset of filopodial protrusions is observed for N>1 filaments growing from beneath the membrane and pushing it upwards, with a velocity which is systematically larger for flexible filaments than for rigid ones. Since filaments are wrapped by the membrane in the protrusion, escaping filaments are not predicted nor observed in this case
- …
