698 research outputs found

    Tribological behaviour of Ti or Ti alloy vs. zirconia in presence of artificial saliva

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    Abutment is the transmucosal component in a dental implant system and its eventual appearance has a major impact on aesthetics: use of zirconia abutments can be greatly advantageous in avoiding this problem. Both in the case of one and two-piece zirconia abutments, a critical issue is severe wear between the zirconia and titanium components. High friction at this interface can induce loosening of the abutment connection, production of titanium wear debris, and finally, peri-implant gingivitis, gingival discoloration, or marginal bone adsorption can occur. As in vivo wear measurements are highly complex and time-consuming, wear analysis is usually performed in simulators in the presence of artificial saliva. Different commercial products and recipes for artificial saliva are available and the effects of the different mixtures on the tribological behaviour is not widely explored. The specific purpose of this research was to compare two types of artificial saliva as a lubricant in titanium-zirconia contact by using the ball on disc test as a standard tribological test for materials characterisation. Moreover, a new methodology is suggested by using electrokinetic zeta potential titration and contact angle measurements to investigate the chemical stability at the titanium-lubricant interface. This investigation is of relevance both in the case of using zirconia abutments and artificial saliva against chronic dry mouth. Results suggest that an artificial saliva containing organic corrosion inhibitors is able to be firmly mechanically and chemically adsorb on the surface of the Ti c.p. or Ti6Al4V alloy and form a protective film with high wettability. This type of artificial saliva can significantly reduce the friction coefficient and wear of both the titanium and zirconia surfaces. The use of this type of artificial saliva in standard wear tests has to be carefully considered because the wear resistance of the materials can be overestimated while it can be useful in some specific clinical applications. When saliva is free from organic corrosion inhibitors, wear occurs with a galling mechanism. The occurrence of a super-hydrophilic saliva film that is not firmly adsorbed on the surface is not efficient in order to reduce wear. The results give both suggestions about the experimental conditions for lab testing and in vivo performance of components of dental implants when artificial saliva is used

    Native cattle breeds of Southern Italy: karyological profile

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    Italian typical products of animal origin are strictly linked to native breeds. Their protection requires control of their reproductive and productive abilities. Hence the need for karyological studies to identify subjects with chromosome abnormalities linked to hypofertility or sterility. We report the results of karyological analyses carried out from January 2008 to December 2008 on 145 cattle of native breeds (Agerolese, Cinisara, Modicana and Podolica) reared in Southern Italy so as to evaluate and characterize the presence of chromosome abnormalities in subjects with normal phenotypes. Besides the 128 karyologically normal subjects (2n=60, XY and 2n=60, XX), 17 were carriers of rob (1;29) and one male was a carrier of cellular chimerism 2n=60, XX/XY. According to our data there is a high frequency of rob (1;29) in Cinisara and Podolica breeds while in Agerolese there was only one case of rob (1;29) and none in Modicana

    Chromosome analyses in dairy cows exposed to dioxins and dioxin-like PCBs using the SCE test

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    Peripheral blood cultures were performed to study the sister chromatid exchanges (SCE) in samples from 15 cows (Valdostana x Piedmontese crossbreds) showing average milk values of dioxins+furans+PCBs higher (18.56 pg/g of fat as WHO-TEQ) than those permitted (6.0 pg/g of dioxins+furans+PCBs as WHO-TEQ) and the results were compared with samples from 16 Valdostana dairy cows (1.75 pg/g of fat as WHO-TEQ) used as control. Significant (P<0.01) higher mean number of SCE/cell (7.10±2.8) were found in cows showing higher levels of dioxins and PCB compared to those achieved in the controls (SCE/cell=5.24±2.51)

    Article influence of the casein composite genotype on milk quality and coagulation properties in the endangered agerolese cattle breed

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    The aim of this study was the characterization of CSN1S1, CSN2 and CSN3 genetic variability in Agerolese cattle, and the investigation of the effect of casein composite genotypes (CSN1S1, CSN2 and CSN3) on quality and coagulation traits of the corresponding milk. To these purposes, blood and milk from 84 cows were sampled and analysed. Allele frequencies at CSN2 and CSN3 revealed no Hardy–Weinberg equilibrium in the population with a prevalence of allele A2 for CSN2 and allele B for CSN3. BBA1A2AB and BBA2A2AB composite genotypes were the most common in the population. BBA1A2AB showed a higher total solids and fat content (12.70 ± 0.16 and 3.93 ± 0.10, respectively), while BBA2A2BB showed the best coagulation properties (RCT 12.62 ± 0.81; k20 5.84 ± 0.37; a30 23.72 ± 1.10). Interestingly, the A2 allele of CSN2 was very widespread in the population; thus, it will be intriguing to verify if A2A2 Agerolese cattle milk and the derived cheese may have better nutraceutical characteristics

    Conservation actions for restoring the coastal lagoon habitats: Strategy and multidisciplinary approach of LIFE Lagoon Refresh

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    The Habitat Directive of European Union lists Costal Lagoons (habitat code 1150*) among priority habitats because they are in danger of disappearance. Natural ecosystems may recover from anthropogenic perturbations; however, the recovery can follow natural restoration or it can be redirected through ecological restoration by anthropogenic intervention. Accordingly, by collecting the available theoretical indications for restoration of estuarine and coastal areas, a methodological approach was detailed andit can be summarised into five issues: (i) Environmental context from which it began; (ii) Desired state to be achieved; (iii) Policies and socio-economic context; (iv) Typology of recovery and/or improvement of habitats and ecosystems; and (v) Methods for monitoring the impact of the project. The project strategy, management and measures of LIFE Lagoon Refresh were also presented and discussed, as a case study for the implementation of the multidisciplinary approach for restoration ecology in transitional waters. The project takes place in the northern Venice Lagoon (Italy), started in 2017 and it lasts 5 years. In the Venice Lagoon, since the 20th century, strong reductions of the typical salinity gradient of buffer areas between lagoon and mainland, and of reedbed extensions have occurred due to historic human interventions, with negative consequences on coastal lagoon habitats. To improve the conservation status of habitats and biodiversity of the area, the LIFE Lagoon Refresh project included several conservative actions, which are (i) the diversion of a freshwater flow from the Sile River into the lagoon; (ii) the restoration of intertidal morphology, through biodegradable structures; (iii) the reed and aquatic angiosperm transplantations with the involvement of local fishermen and hunters, and (iv) the reduction of hunting and fishing pressures in the intervention area. To achieve the restoration of the lagoon environment, the strategy of the project covered a combination of different aspects and tools, such as planning activities, through the involvement of local Institutions and communities; stakeholder's involvement to increase awareness of environment conservation and socioeconomic value improvement; an ecological engineering approach; numerical models as supporting tool for planning and managing of conservation actions; environmental monitoring performed before and after the conservation actions

    Salvage carbon dioxide transoral laser microsurgery for laryngeal cancer after (chemo)radiotherapy: a European Laryngological Society consensus statement

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    Purpose: To provide expert opinion and consensus on salvage carbon dioxide transoral laser microsurgery (CO2 TOLMS) for recurrent laryngeal squamous cell carcinoma (LSCC) after (chemo)radiotherapy [(C)RT]. Methods: Expert members of the European Laryngological Society (ELS) Cancer and Dysplasia Committee were selected to create a dedicated panel on salvage CO2 TOLMS for LSCC. A series of statements regarding the critical aspects of decision-making were drafted, circulated, and modified or excluded in accordance with the Delphi process. Results: The expert panel reached full consensus on 19 statements through a total of three sequential evaluation rounds. These statements were focused on different aspects of salvage CO2 TOLMS, with particular attention on preoperative diagnostic work-up, treatment indications, postoperative management, complications, functional outcomes, and follow-up. Conclusion: Management of recurrent LSCC after (C)RT is challenging and is based on the need to find a balance between oncologic and functional outcomes. Salvage CO2 TOLMS is a minimally invasive approach that can be applied to selected patients with strict and careful indications. Herein, a series of statements based on an ELS expert consensus aimed at guiding the main aspects of CO2 TOLMS for LSCC in the salvage setting is presented

    Conservation actions for restoring the coastal lagoon habitats: Strategy and multidisciplinary approach of LIFE Lagoon Refresh

    Get PDF
    The Habitat Directive of European Union lists Costal Lagoons (habitat code 1150*) among priority habitats because they are in danger of disappearance. Natural ecosystems may recover from anthropogenic perturbations; however, the recovery can follow natural restoration or it can be redirected through ecological restoration by anthropogenic intervention. Accordingly, by collecting the available theoretical indications for restoration of estuarine and coastal areas, a methodological approach was detailed andit can be summarised into five issues: (i) Environmental context from which it began; (ii) Desired state to be achieved; (iii) Policies and socio-economic context; (iv) Typology of recovery and/or improvement of habitats and ecosystems; and (v) Methods for monitoring the impact of the project. The project strategy, management and measures of LIFE Lagoon Refresh were also presented and discussed, as a case study for the implementation of the multidisciplinary approach for restoration ecology in transitional waters. The project takes place in the northern Venice Lagoon (Italy), started in 2017 and it lasts 5 years. In the Venice Lagoon, since the 20th century, strong reductions of the typical salinity gradient of buffer areas between lagoon and mainland, and of reedbed extensions have occurred due to historic human interventions, with negative consequences on coastal lagoon habitats. To improve the conservation status of habitats and biodiversity of the area, the LIFE Lagoon Refresh project included several conservative actions, which are (i) the diversion of a freshwater flow from the Sile River into the lagoon; (ii) the restoration of intertidal morphology, through biodegradable structures; (iii) the reed and aquatic angiosperm transplantations with the involvement of local fishermen and hunters, and (iv) the reduction of hunting and fishing pressures in the intervention area. To achieve the restoration of the lagoon environment, the strategy of the project covered a combination of different aspects and tools, such as planning activities, through the involvement of local Institutions and communities; stakeholder’s involvement to increase awareness of environment conservation and socioeconomic value improvement; an ecological engineering approach; numerical models as supporting tool for planning and managing of conservation actions; environmental monitoring performed before and after the conservation actions
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