Tissue engineering technologies: just a quick note about transplantation of bioengineered donor trachea and augmentation cystoplasty by de novo engineered bladder tissue

Per ingegneria dei tessuti si intende un settore scientifico multidisciplinare volto alla realizzazione in vitro di strutture biologiche di ricambio, atte a rinforzare o sostituire organi umani in precarie condizioni. Diversi tipi di materiali – quali polimeri sintetici biodegradabili (acido poliglicolico, PGA; acido polilattico, PLA; copolimero PGA-PLA), sostanze di derivazione naturale (alginato, collagene), matrici acellulari (submucosa del piccolo intestino, SIS; submucosa acellulare vescicale, ABS), o tra loro assemblati (PGL legato a collagene) – sono stati impiegati come intelaiature (scaffold) sia prive di cellule ("unseeded technique"), allo scopo di promuovere, in vivo, nell'organo in cui vengono impiantate, naturali processi rigenerativi, non sempre, però, attuantisi, sia per sviluppare, in vitro, previa semina, nella loro compagine, di cellule del potenziale ricevente (autologous cell seeded technique), un tessuto ingegnerizzato, idoneo all'impiego in chirurgia ricostruttiva. Recentemente, la trachea di donatore morto, opportunamente decellularizzata, è stata usata quale scaffold per essere seminata, in vitro, con cellule epiteliali e condrociti derivati da cellule staminali mesenchimali del ricevente, al fine di ottenere un segmento ingegnerizzato di via respiratoria tale da sostituire il grosso bronco sinistro, gravemente malacico, del ricevente. In riferimento alle applicazioni in ambito urologico, è stato coronato da successo l'impiego di una "seeded technique" (cellule autologhe seminate su scaffold composto di PGA legato a collagene) per confezionare tessuto ingegnerizzato vescicale usato nella realizzazione di cistoplastica d'ampliamento in soggetti affetti da "vescica neurologica", ormai in fase estremamente grave (livelli alti di pressione endovescicale, compliance vescicale molto ridotta). L'impiego di cellule autologhe, ottenute, mediante biopsia, dai tessuti del ricevente, evita il rischio di rigetto dopo l'impianto. Peraltro, il ricorso a cellule organo-specifiche "adulte" presenta dei limiti correlati alla loro raccolta (potenziali complicazioni associate all'invasività della biopsia) ed alle difficoltà di cultura in vitro data la loro bassa capacità proliferativa. Pertanto, sono stati presi in considerazione diversi tipi di cellule staminali, embrionali o adulte, e di cellule progenitrici, al fine di utilizzarle in ingegneria dei tessuti. Per queste tecnologie risulta indispensabile l'impiego di bioreattori, atti a riprodurre, nelle culture cellulari, le condizioni dinamiche chimico-fisiche proprie dell'ambiente tissutale naturale, ed a consentire la valutazione delle risposte delle strutture bioingegnerizzate a differenti segnali biochimici e forze meccaniche

Revealing quantum statistics with a pair of distant atoms

Quantum statistics have a profound impact on the properties of systems composed of identical particles. In this Letter, we demonstrate that the quantum statistics of a pair of identical massive particles can be probed by a direct measurement of the exchange symmetry of their wave function even in conditions where the particles always remain spatially well separated and thus the exchange contribution to their interaction energy is negligible. We present two protocols revealing the bosonic or fermionic nature of a pair of particles and discuss possible implementations with a pair of trapped atoms or ions.Comment: 4+13 pages, v2 corresponds to the version published by PR

Propagation and spectral properties of quantum walks in electric fields

We study one-dimensional quantum walks in a homogeneous electric field. The field is given by a phase which depends linearly on position and is applied after each step. The long time propagation properties of this system, such as revivals, ballistic expansion and Anderson localization, depend very sensitively on the value of the electric field $\Phi$, e.g., on whether $\Phi/(2\pi)$ is rational or irrational. We relate these properties to the continued fraction expansion of the field. When the field is given only with finite accuracy, the beginning of the expansion allows analogous conclusions about the behavior on finite time scales.Comment: 7 pages, 4 figure

Characterization of organic compounds from biosolids of Buenos Aires city

143-152The use of biosolids as a source of organic matter improves the physical and chemical properties of agricultural soils, resulting in an increase in crop yields. In previous studies, between 29-45 percent of sludge-borne carbon was recalcitrant a year after land application of biosolids from Buenos Aires City. Although high concentrations of some persistent organic pollutants have been worldwide reported to be present in this waste, this study has not been addressed in Argentina until now. Therefore, our aim was to characterize the organic compounds in Buenos Aires City's biosolids. Different extracting solvents were evaluated for ultrasound-assisted extraction (UAE). Results indicated that the combination of hexane: acetone (3:2, v/v) showed the highest extractability, allowing the identification of a wide range of organic compounds, without a clean-up or a pre-concentration step. The organic compounds mainly consisted of fatty acids, n-alkanes and steroids, with concentrations of persistent organic pollutants below detection limits. We conclude that the recalcitrant organic fraction reported in previous research is mainly due to the presence of stable sterols

An Evaluation of The Migrant Access Project Plus Final Report

The Migrant Access Project operated within West and South Leeds, 2018 until March 2020. It aimed to provide support to new and existing migrant communities to better help them integrate, and thus reduce pressure on existing services, minimising low level tensions and thereby concerns from settled communities within Leeds. Our 2018 interim report focused upon the Migrant Access Plus Project (MAPP) that was running in the Armley and Holbeck areas of the city. Our 2019 report explored the extension of the project into three additional areas as part of the second year of delivery: Beeston Hill, Little London/Hyde Park/Woodhouse and New Wortley. This final report draws together all findings and overall learning from the delivery of MAPP, following a third year of extension funding

Trade-off between multiple-copy transformation and entanglement catalysis

We demonstrate that multiple copies of a bipartite entangled pure state may serve as a catalyst for certain entanglement transformations while a single copy cannot. Such a state is termed a "multiple-copy catalyst" for the transformations. A trade-off between the number of copies of source state and that of the catalyst is also observed. These results can be generalized to probabilistic entanglement transformations directly.Comment: Essentially the journal version. 7 pages, no figures. Minor correction

Polyolefin Fibres for the Reinforcement of Concrete

Given that concrete has limited tensile strength, it has been necessary to combine its properties with the use of steel bars. This resulted in the arrival of reinforced concrete which was the main solution used in structures in the last century. Partial or even full substitution of steel bars for fibres would not only allow the cost of a structure to be reduced but also provide certain improved properties. Modern fibre‐reinforced concrete (FRC) now permits reduction or substitution of steel bars that has given rise to the commonly named structural FRC. Advances in the plastic industry during the last three decades have allowed the production of macro‐polymer fibres as an alternative to steel fibres due to their chemical stability and lower weights for analogous residual strengths. After 30 years of research and practice, polyolefin‐based macro‐fibres have offered additional advantages such as safe handling, low pump wear and reduction in weight when transported and stored. This chapter provides an overview of the properties and structural capacities of polyolefin fibre‐reinforced concrete (PFRC). Furthermore, the respective codes and test methods are examined. Moreover, the results obtained for structural design and the mechanical properties, found both in the literature and in practice, are supplied and discussed

Patients’ self-perception of dentofacial attractiveness before and after exposure to facial photographs

open4noObjective: To determine whether exposure to pretreatment photographs of themselves influenced patients’ self-perception of dentofacial attractiveness and willingness to undergo treatment. Materials and Methods: A total of 100 subjects of white ancestry aged 18 years or older (Study Group) and 100 sex- and age-matched controls (Control Group) were selected. Photographs of the frontal view of the face and the profile view of the face, both at rest and while smiling, were taken of each participant. Only Study Group subjects were given a printed copy of their own images to be examined at home between the initial observation (T0) and a set date an average of 30 days later (T1). Each of the 200 subjects in the study completed a questionnaire at T0 and T1 exploring happiness regarding their smiles and their facial profiles, as well as willingness to undergo treatment. Results: At T1 in the Study Group, 50% of subjects responded with a lower opinion of their facial profiles than at T0; 11% and 45% were willing to undergo more comprehensive procedures to change the appearance of their smiles and profiles, respectively. No statistically significant change was seen in questionnaire answers between T0 and T1 for the Control Group. Conclusion: Laypeople generally are not aware of their facial profiles. Pretreatment photograph exposure can increase profile self-awareness, an important factor in reducing the discrepancy between orthodontists’ and patients’ visual emphasis on dentofacial esthetics.openGiulio Alessandri Bonetti; Andrea Alberti; Claudio Sartini; Serena Incerti ParentiGiulio Alessandri Bonetti; Andrea Alberti; Claudio Sartini; Serena Incerti Parent

The intradermal vaccination: past experiences and current perspectives

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