1,721,031 research outputs found
Proprietà osteoinduttive di superfici micro e nano strutturate per l'implantologia ossea
Full text linkBone replacement procedures can be used to replace missing teeth, for repairing bone defects and restoring bone structures. To obtain a functional and long-term repair, bone substitutes, composed of metal or synthetic materials, must firmly join to natural bone. This process, named osseointegration, is a consequence of the migration of undifferentiated cells from the host surrounding tissues to the prosthesis and their differentiation towards mature bone cells producing bone tissue that firmly anchor the implant in place. When cells fail to do this, a soft capsule surrounds the implant resulting in the dislodgment of the prosthesis or low quality repair. In the biological environment, the most of cells must adhere to a substrate to live and proliferate. Moreover, they are able sense the features of the bonding surface (e.g., roughness, geometry) and this can affect the differentiation pathway of cells thus leading to a different phenotype. To achieve a stable anchorage, mesenchymal stem cells (MSCs) must differentiate toward mature osteoblasts rather than connective tissue cell types.
In light of these considerations, the aim of this project is to develop the technology to produce potentially transplantable osteoinductive devices for the replacement and the repair of bone defects. To achieve this purpose, the injection molding process was optimized to realize cylindrical micro- or nano-pillars on the scaffold surface. This technique has allowed to obtain a high degree of feature replication thus making the micro imprinting an effective and efficient technique that is extremely interesting from a commercial point of view. Subsequently, the osteoinductive properties of micro- and nanostructured surfaces were tested in vitro using bone marrow derived MSCs.
At different time points various assays were performed in order to assess cell adhesion, morphology and cell viability. The analysis of cell differentiation was carried out through the evaluation of calcium deposition and the quantification of osteocalcin expression.
Collectively, our data show that both micro- and nano-structured surfaces possess osteoinductive properties, allowing MSC differentiation without any inductive growth factors. In particular, a relationship between dimensional features of surface topography and differentiative potential has been noted. Indeed, the increase in pillar diameters and interpilllar distances leads to an enhancement of calcium deposition and OC expression. On the contrary, both micro- and nano-structured surfaces and their features seem to be uneffective on cell adhesion and proliferation. Further in vivo studies will be necessary to confirm the osteoinductive properties of the selected surface geometries and verify their osteointegratio
Metodi di raccolta e di classificazione dei dati di mortalità infantile confronto tra '800 e '900
No full textGli studi di mortalità infantile sono numerosi tanto per il passato quanto per il presente perchè permettono, attraverso l'individuazione delle condizioni socio-economiche sanitarie di una popolazione, di conoscere la qualità di vita e lo sviluppo di una collettività
[Further observations on healthy carriers of Salmonellae in the province of Ferrara (1976-1977),(author's transl)].
No full text366 Salmonella strains (2.03%), belonging to 40 different serotypes, were isolated by Authors in 1976 from feces of healthy subjects, in the province of Ferrara; 262 strains (1.45%), belonging to 34 serotypes, were isolated in 1977. The Authors found no significant difference between isolations carried out in both sexes; highest frequencies of isolation were recorded in August, September and October. We have also reported the serotypes more frequently isolated by various Authors from sick and healthy men feces, from animal feces, from sewage and from surface waters
Congenital malformations observed at the Obstetric Department of Ferrara from 1973 to 1978 (clinico-statistical study)
No full textThe Authors illustrate the results of a clinicostatistical research conducted on 139 cases of malformations corresponding to 13.07% of 10.633 births of the Obstetric Clinic of Ferrara during the period 1973-1978. The following variables were examined: type of malformation, sex, wight, duration of pregnancy, type of delivery, mother's age and order of birth
La mortalità infantile nel Comune di Ferrara dal 1960 al 1980
No full textGli Autori hanno osservato l'evoluzione della mortalità infantile nella popolazione presente del Comune di Ferrara dal 1960 al 1980 in relazione al sesso, età alla morte, causa di morte.
Tutte le componenti della mortalità infantile hanno registrato una diminuzione
La qualità dei dati statistici: la nostra esperienza nell'analisi della mortalità infantile sulla popolazione "residente" della provincia di Ferara
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Gram-negative flora of horticulture products prevalently to be consumed fresh. II, Acinetobacter calcoaceticus
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Gram-negative flora of horticultural produce destined for consumption mainly in the raw state
No full textA survey has been carried out to evaluate the recovery of Enterobacteriaceae in freshly consumed horticultural products. 64 samples of these vegetables random chosen in different stores in the General Vegetable Market of Ferrara have been examined among the families of Compositae (lettuce, prickly lettuce, cabbage lettuce, common chicory, artichoke), Umbrelliferae (curly parsley, carrot, celery, fennel), Cruciferae (garden cabbage, red radish), Liliaceae (onion), and Solanaceae (tomato). 654 bacterial lines were isolated, of which 92.5% were Enterobacteriaceae, found in all kinds of horticultural products, the more contaminated being celery, followed by fennel, onion, common chicory, curley parsley, tomato; less contaminated were the other vegetables. Serratia was found in 29.6% of the samples, Escherichia in 28%, Enterobacter in 21.6%, Hafnia in 8.3%, citrobacter in 4.9%, Klebsiella in 2.3% and Yersinia enterocolitica in 1.5%. The importance of horticultural products as source of cont..
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