1,721,365 research outputs found
Contrast-enhanced ultrasound in the diagnosis of hepatocellular carcinoma
No full textSurveillance of patients at risk of developing hepatocellular carcinoma (HCC) is based on ultrasound (US) examinations performed at either 6 or 12 month intervals. Early detection of HCC in patients with cirrhosis is a challenging issue, since the different entities that are involved in the multi-step process of hepatocarcinogenesis--such as low-grade and high-grade dysplastic nodule--share common US features. Contrast-enhanced US allows reliable detection of arterial neoangiogenesis associated with a malignant transformation. Several reports have shown that the ability of contrast-enhanced US to diagnose HCC currently approaches that of optimized multidetector computed tomography (CT) or dynamic magnetic resonance (MR) imaging protocols. The use of contrast-enhanced US to characterize nodular lesions in cirrhosis has been recently recommended by the clinical practice guidelines issued by the European Federation of Societies for Ultrasound in Medicine and Biology and the American Association for the Study of Liver Diseases. However, contrast-enhanced US has not resulted in any significant improvement in the ability of US to detect small tumor foci, since a comprehensive assessment of the whole liver parenchyma cannot be accomplished during the short duration of the arterial phase. Hence, CT or MR imaging are still mandatory for proper intrahepatic staging of the diseas
Planning urban quality as a shared value. The role of social communication networks
No full textUrban quality is a concept that plays a central role in the debate about planning. A theory of urban quality should give a scientific interpretation of it, clarifying its possible role in the decision-making process and helping to define the tools for making it a working reality. A definition of “quality” can result only from multidisciplinary confrontation of different approaches. Quantitative approach, as expression of scientific and technical culture, and qualitative approach, more related to human science, can be integrated into a complex view of the problem. In this paper a set of performances is proposed to drive urban changes towards qualities of the city that can be considered satisfactory by the local communities involved in planning process. Furthermore, the relationship between this set of performances and the tools that decision makers, technicians and citizens use to modify the form and organisation of the city is investigated. This allows a definition of the twofold role that social communication networks play:
- to support communication from decision makers to users to the purpose of user requirements elicitation and of broadcasting the outcomes of urban policies;
- to support participation of urban communities to the decision-making process, that means communication from users to decision makers, in order to define priorities in urban policies and to verify consensus around their outcomes
Review article: liver transplantation for HCC. Treatment options on the waiting list
No full textThe most widely adopted criteria to admit and maintain patients with HCC and cirrhosis in the waiting list for liver transplantation are the Milano criteria, consisting in the presence of a single tumour ≤ 5 cm in diameter or up to three tumours, none exceeding 3 cm in diameter. Since the average time to transplantation has become longer than 10-12 months in most European and American Centers, the exclusion from the list during the waiting period due to increase of the neoplasm over the established criteria is not uncommon at present. It is mandatory, therefore, to seek an effective therapeutic strategy for patients with HCC waiting for transplantation. Surgical resection and eventual subsequent salvage transplantation seems a cost-effective strategy in resectable HCC. In unresectable neoplasms both transarterial chemoembolization and percutaneous ablation techniques are currently used and one or the other are chosen according to individual applicability, limitations and specific risks. However, although positive trends were reported, no definitive evidence has been produced so far about their efficacy in increasing patient's survival and decreasing tumour recurrence rates after transplantation. Adult-to-adult living donor liver transplantation is one possible way to shorten the waiting list, but this strategy involves important ethical implications. At present it appears justified to take it into consideration only if the waiting time for cadaveric OLT is expected to exceed 7 months. A more general and definitive attempt to overcome problems related to long waiting times for patients with HCC and relatively preserved hepatic function has been introduced in the USA very recently and consists in prioritizing patients with HCC. However, the overall efficacy of this approach will be established only in some years
Evaluation of three Italian tuffs (Neapolitan Yellow Tuff, Tufo Romano and Tufo Etrusco) as compatible replacement stone for Römer tuff in Dutch built cultural heritage
No full textRhenish tuffs from the volcanic Eifel region in Germany, in particular the so-called Römer tuff, are among the most prominent and voluminous natural stones in Dutch monuments. The Römer tuff has been used since Roman times, and was widely used again in Romanesque (and to a lesser extent Romano-Gothic and early Gothic) architecture. The limited (or non) availability of Römer tuff for restoration purposes is posing an increasing problem. Last decennia, the availability of Römer tuff was practically limited to blocks from the lower parts of the pyroclastic flows with abundant basalt (and other) xenoliths, giving the rock a different appearance from its traditional type; the different types of Römer tuff also demonstrate different physical and hygric properties. Given the wide use of tuff stone in Italian architecture, several Italian tuffs have been evaluated in search of a compatible replacement stone for Römer tuff. The replacement stones should approach the original as much as possible, that is, in terms of authentic appearance, physical characteristics and durability. The Italian tuffs evaluated include tuffs commercially denominated as Tufo Etrusco and Tufo Romano (from the central part of Italy) and a variety of Neapolitan Yellow Tuff (Naples region). Hygric behaviour, resistance to frost-thaw cycles, petrographic characteristics and mineralogy of Italian tuffs have been determined and compared with original Römer tuff. In all three cases, resistance to frost-thaw cycles is unfortunately shown to be considerably less than that of original Römer tuff. In addition, hygric expansion of the Neapolitan Yellow Tuff appeared to be considerably larger than that of original Römer tuff. Of the tuffs evaluated, the variety of Neapolitan Yellow Tuff is a good match with the original Römer tuff in terms of visual appearance. It has already been sparsely used in the Netherlands in minor amounts. However, the durability characteristics require additional evaluation. © The Geological Society of London 2010
Contrast-enhanced ultrasonography features of extramedullary hematopoiesis presenting as a presacral mass: an update of the literature.
No full text
Renders technology in Italian Renaissance: The case of the Lucchesian villas
No full textRMIT and Media StudiesArchitectur
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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