1,721,471 research outputs found
Application of blood-pool agents in visualization of peripheral vessels
No full textEur Radiol. 2007 Mar;17 Suppl 2:B18-23.
Application of blood-pool agents in visualization of peripheral vessels.
Giovagnoni A, Catalano C.
Source
Istituto di Radiologia, Università Politecnica delle Marche, Ancona, Italy. [email protected]
Abstract
Effective arterial imaging is essential in patients with peripheral arterial disease (PAD) in whom a revascularization procedure is planned. Digital subtraction angiography (DSA) has traditionally been regarded as the gold standard for imaging in peripheral arterial disease, but this technique is subject to certain limitations, such as the risks of adverse reactions associated with arterial catheterization and iodinated contrast agents. Contrast-enhanced magnetic resonance angiography is now recommended as an effective and useful imaging technique in peripheral arterial disease, since it offers high enhanced contrast between blood and stationary tissue and fast acquisition times. However, extracellular gadolinium contrast agents rapidly diffuse into the interstitial spaces, and thus are suitable only for first-pass imaging. This limitation can be overcome by the use of blood-pool (intravascular) contrast agents, such as gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany), which are retained within the blood vessels and hence facilitate both first-pass and steady-state imaging with high spatial resolution. Blood-pool agents, therefore, offer improved imaging, particularly of distal vessels, compared with extracellular contrast agents. Examples of first-pass and steady-state imaging with gadofosveset are presented.
PMID:
17650556
[PubMed - indexed for MEDLINE
Nature based solutions e urban greening: importanti spazi di azione per fitosociologi
No full textNella progettazione e gestione del verde urbano l'impiego di specie delle comunità erbacee spontanee consente di creare stepping stones per flora e fauna locale e, al contempo, costruire spazi verdi a basso input energetico e basso costo di manutenzione, che, se opportunamente progettate, possono avere anche un valore ornamentale. Le nature-based solutions sono consigliate anche da molti organismi istituzionali.
L'urban greening basato su criteri naturalistici dovrebbe andare di pari passo con una pianificazione delle periferie urbane e delle aree periurbane finalizzata alla realizzazione di green belts,
che potrebbero essere utilizzate come donor meadows per la realizzazione di interventi di urban greening adatti ad offrire nuovi spazi alla biodiversità locale, erogare servizi ecosistemici, far conoscere e sperimentare la natura ai cittadini.
Basandosi su breve rassegna di casi studio, verranno proposte alcune considerazioni di carattere generale sulle molteplici potenziali applicazioni della vegetation science nelle fasi di progettazione, realizzazione e monitoraggio di interventi di miglioramento della biopermeabilità urbana, con particolare riferimento a: green belts, urban corridoirs e verde pensile estensivo. Molte esperienze di questo tipo sono portate avanti con successo in alcune città europee, anche se le linee guida e normative maturate in ambito centro-europeo presentano numerose criticità ed inadeguatezze, se applicate alle città a clima mediterraneo senza opportuni correttivi
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The role of MRI in prostate cancer management: pushing the diagnostic frontier
Full text linkThe role of Magnetic Resonance Imaging (MRI) in prostate cancer (PCa) diagnostic work-up has drastically
changed over the last 40 years. Years of innovations
have produced outstanding advances in diagnostic imaging and MR-guided interventional procedures. In early 2019, the updated version of the PI-RADS score system was released. The same year a real breakthrough
occurred when the updated version of the European
Association of Urology (EAU) guidelines was released:
MRI is currently recommended as the first line imaging modality for biopsy-naive patients. Among all the
published studies supporting the use of MRI in the diagnostics of PCa, robust trials have played a pivotal role:
The PROMIS study, the MRI-FIRST study, the PRECISION
study and the 4M trial. The success of MRI is heavily
dependent on high-quality image acquisition and interpretation to minimise the number of equivocal cases,
standardise negative MRIs, reduce overdiagnosis and
overtreatment and promote biopsy improvement and
focal therapeutic approaches. Future perspectives include the spread of non-contrast MRI as the most efficient way to face the expected upcoming large number
of MRI requests for PCa diagnosis and the application of
artificial intelligence-based tools that might profoundly shape modern imaging, with major implications for
medical practice. The goal is to review PCa natural history and management, with an insight on MRI applications and future perspectives
A new adversarial training approach based on CTF
No full textProtecting digital assets has become a critical priority for individuals, businesses, and governments. As a result, there is a growing need for effective cybersecurity education that equips individuals with the skills and knowledge to identify, prevent, and respond to cyber threats. In this article, we examine the potential of using innovative educational methodologies, such as Capture the Flag (CTF), for teaching cybersecurity effectively and we propose an innovative educational methods. The platform to support it and an experiment to validate it are currently in progress
Reinfusion and concentration of ascitic fluid during hemodialysis in a cirrhotic uremic patient
No full textManagement of tense ascites in cirrhotic patients on chronic hemodialysis
is still a matter of speculation. A considerable problem with these
patients is the frequent occurrence of hypotension during ultrafiltration.
We describe a patient in whom ascitic fluid was reinfused on the arterial
line and ultrafiltrated during standard treatment by using a single
dialysis monitor, standard dialysis (SD) lines, and a standard hollow-
fiber dialyzer. After 30 to 60 minutes of dialysis, with the patient lying
on his left side, a gauge 16 IV catheter was introduced into the left lower
abdomen and connected to the reinfusion line. The ascitic fluid was pumped
from the abdomen to the arterious inlet of the coil at 500 to 2,000 mL/hr
and ultrafiltered. In an individual patient, 13 sessions of ascites
reinfusionultrafiltration dialysis (ARD) were performed over 3 months and
compared with 18 SD sessions performed during the same period. In all
procedures, the same SD equipment was used. During ARD, the average weight
loss was 2.9 (SD 1.0) kg compared with a weight loss of 0.3 (0.04) kg
during SD (P < 0.01). Baseline mean blood pressure was similar in both
procedures; after starting dialysis, mean arterial pressure (MAP) dropped
by an average of 15 mm Hg at 30 and 60 minutes. Subsequently, during ARD,
MAP increased progressively by an average of 20 mm Hg at 180 minutes,
whereas MAP did not change significantly during SD. Comparison between
procedures by nonparametric one-way analysis of variance showed that body
weight became significantly different at 120, 150, and 180 minutes (P <
0.01) and MAP at 150 and 100 minutes (P < 0.02 and P < 0.01, respectively).
No major complications occurred. During ARD, on average urea reduction rate
was 67%. ARD may represent an effective and safe combination between
hemodialysis and the palliative treatment of tense ascites in cirrhotic
uremic patients
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