186,323 research outputs found
Innovative approaches to study exosome biogenesis and uptake: Insights into Mannose Receptor-mediated uptake and immunomodulatory effects on Dendritic Cells
No full textExosomes are gaining recognition as important mediators of intercellular communication, and researcher are focused on their potential clinical applications. However, challenges in accurately isolating exosomes from other types of Extracellular Vesicles (EVs) have hindered both their functional studies and clinical utility. Moreover, many aspects related to exosome biogenesis, interaction with recipient cells, and selective uptake mechanisms remain poorly understood. The aim of this study was to investigate the mechanisms of exosomes internalization and their and immunomodulatory effects on immune cells. To distinguish exosomes from the other EVs, we used the Bodipy FL C16, a fluorescent palmitic acid analogue, that enabled us to identify a discrete subpopulation of small exosomes.The Bodipy C16 is incorporated in the fluorescent phospholipids into specific intracellular organelles, culminating in their integration into the exosomal membrane. The characterization of Bodipy exosomes sheds light on their enrichment in tetraspanin markers, notably CD63 and CD81, along with a minor proportion of CD9. The authentication of the exosomal nature of Bodipy vesicles is achieved through nanoFACS sorting and electron microscopy. As awareness of the pivotal role of exosomes, particularly in immune modulation, continues to grow, the question of their selective or non-selective uptake by recipient cells becomes a central focus. Recent studies have demonstrated that exosomes are particularly enriched in high mannose glycans. Therefore, we investigated exosome internalization by antigen-presenting cells, specifically immature dendritic cells (iDCs) characterized by their expression of the mannose receptor (MR). Hypoxic conditions, which are prevalent in the tumor microenvironment, can induce changes in glycosylation patterns. Thus, we aimed to evaluate the specific uptake mediated by the MR of exosomes secreted under normoxic or hypoxic conditions. This study not only explores the uptake of Bodipy exosomes by iDCs but also elucidates their influence on these cells through fluorescence quantification. The results reveal that exosomes are selectively internalized via the MR by iDCs, prompting significant phenotypic transformations within the DCs, thereby shedding light on the profound immunomodulatory capabilities of exosomes within the innate immune system. This findings shed light on the immunomodulatory properties of exosomes in the innate immune system. However, further research is required to fully understand the underlying mechanisms and utilize the therapeutic potential of these results
Laser scanner survey and 3-d modeling of the Cetara tower on the amalfitan coast.
No full textThe main goal of this work is to study and experiment the use of the terrestrial laser scanning technique in order to survey an architectural heritage. The experiment concerns the survey and the modeling of a tower characterized by a very articulated plan and a complex geometry placed in Cetara (Amalfitan Coast). We used three different laser scanners: Cyrax HDS2500, Optech ILRIS-3D and Riegl LMSZ420.
The surveys carried out with the three different instruments demanded different design, planning and execution of the experiment. In order to carry out the survey of the Tower it has been necessary to run a high number of scans from various points of view and with different resolutions. This was necessary for the correct reconstruction of the architectonic elements which are complex and difficult to bring to simple and linear geometries. Modeling has been carried out using several commercial softwares used to filter the scan results and to reconstruct the 3D model of point clouds and the solid model by means of triangulation.
By means of the DTMs derived from the three laser scanners we finally elaborated a number of orthophotos using a digital photogrammetrical software. We started from the images acquired with a semi-metric camera, the Nikon D100; we compared our different orthophotos among them and with that one derived from the DTM obtained by means of digital matching on the photogrammetric stereo pair. Such a comparison was made on a number of common check points
Utilizzo di tecniche topografiche e satellitari per produzione e aggiornamento di cartografia per usi di Protezione Civile.
No full textMonitoraggio dell’evoluzione di una frana tramite Laser Scanning
No full textIn questa nota si descrive una applicazione della tecnica laser scanning terrestre al rilievo di una area di vaste proporzioni interessata da un fenomeno franoso di tipo lento. L’area interessata copre circa dieci ettari ed è attualmente monitorata con tecniche tradizionali. Utilizzando un sistema laser scanner di tipo long-range, sono stati effettuati diversi rilievi test per studiare la migliore metodologia da adottare. Per avere tutti i rilievi nel medesimo sistema di riferimento esterno e confrontarli nel tempo, non è stato possibile realizzare sul corpo di frana un frame di riferimento stabile nel tempo e i target sono stati ricollocati a ogni rilievo. E’ comunque possibile individuare vertici esterni alla frana materializzati stabilmente rispetto i quali rilevare con GPS punti di controllo ai quali riferire il rilievo laser. Per ogni rilievo sono state necessarie diverse nuvole di punti, ciascuna inizialmente riferita a un sistema strumentale, successivamente georeferenziate tramite target di forma sferica, riconoscibili nelle scansioni, i cui centro-sfera sono misurati con GPS rispetto a punti stabili esterni. In tal modo in ogni rilievo si possono ottenere DTM del corpo di frana riferiti a un sistema assoluto
- …
