1,720,963 research outputs found
Utilità del doppler ad onda continua per valutare gli effetti della simpaticectomia lombare
No full textClassification of the subclavian steal syndrome with transcranial Doppler
No full textUltrasound has provided a highlight of the different types of subclavian steal The authors report epidemiological and clinical data concerning 40,000 ultrasound examinations performed on epiaortic arteries and particularly the last 12,000 in which Doppler cw., duplex scanner and transcranial Doppler were used. Various types of steal are described: five types of subclavian steal have been classified and patients stratified as being symptomatic and asymptomatic The neurological symptoms are divided as follows: generalized cerebral ischemia, vertebro-basilar ischemia and hemispheric ischemia. Based on this clinical and haemodynamic outline, surgical therapy is indicated and type of surgery suggested
[Ultrasonic quantification, value of color and contribution of transcranial Doppler sonography in carotid artery surgery].
No full textThe authors briefly report their experience regarding the opportunities offered by the use of current ultrasound methods in carotid surgery. They describe: a system for the quantification of athcromasic plaque used to monitor non-operated patients over time; ultrasound methods used to analyse the carotid wall to establish whether it can be utilised as an index of vascular aggression in hypertension, diabetes and atherosclerosis; the use of transcranial Doppler; criteria for the definition of high risk plaque; the applications of eco-color Doppler. The paper also illustrates a new pathology identified by the authors, defined as primary intimal fibrous hyperplasia, and the evolution of the carotid wall after endarterectomy. The structural characteristics of primary hyperplasia can only be shown using ultrasound given that arteriography cannot distinguish it from atheromatic stenosis. After endarterectomy the carotid wall is subject to hematic and hemodynamic stimuli which determine the type of evolution of the wall itself. The authors therefore examine the myointimal reaction, myointimal hyperplasia, early restenosis and late restenosis as different facets of the same phenomenon
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
Classificazione dell'emodinamica venosa e delle varici.
No full textBased on thè presumption that chronic venous insufficiency
(CVI) and varices extremely diffidili to classify and that none
of thè current Classification is sufficiently complete, thè
authors propose a functional Classification of venous hemodynamic
pathology and varices seen from a clinical, anatomotopographical,
etiopathogenetic and hemodynamic point of view.
Such a complex Classification allows thè evolution of thè disease
to be followed over time and to distinguish between benign
and more aggressive forms. It also enables thè results of medicai,
surgical and sclerotherapeutic treatment to be evaluated
not only in terms of their efficacy, but also from a functional,
instrumentai and esthetic point of view
Control of the operated carotid with ultrasound. Anatomical and hemodynamical modifications, both local and intracranial
No full textBackground. A study has been done on the operated carotid monitoring the modifications of the wall and of the flow in the site of the operation and at the intracranial level. Methods. 146 operated carotids were studied using transcranial Doppler, duplex and color. The pre-surgical data were confronted with the postsurgical ones on the 4th day, one month later, 3 months later and every 6 months. Results. The cerebrovascular reactivity (CR) and the cerebral hemodynamic latency time (CHLT), improved in more than half of the patients with stenosis > 80%. When the stenosis is of minor entity, the improvement appears in 10% of the cases. The VCR and CHLT modifications appear within 1 month following the operation. Kinkings are more frequent with the patch (6%) than with the direct suture (3%). The symptomatic restenosis is 2%, while the asymptomatic one is 11%. The restenosis is present in 8% of the cases with direct suture and in 3% of those with suture with patch. Conclusions. The local and intracranial modifications after carotid revascularization depend on new anatomical and hemodynamical situation due to surgery. The response of the wall which can be of four types: myointimal reaction, is a 'physiological' response to the trauma and its thickness does not exceed 3 mm; myointimal hyperplasia, with thickness exceeding 3 mm; early restenosis (12 to 18 months); late restenosis (after 2 years). Substantial differences in velocity between systole and diastole and the systolic stress favor hyperplasia more than low velocities with smaller differences
A new classification of varicose veins to compare various surgical strategies
No full textConsidering the presupposition that chronic venous insufficiency (CVI) and varicose veins classifications are extremely difficult, and that none of those presently in use are sufficiently complete, the authors propose the classification of the haemodynamic venous disease (HVD) and of the varicose veins from the clinical, anatomotopographical, etiopathogenetical and haemodynamical point-of-view. This type of classification allows us to closely follow the disease's evolution, to distinguish the benign forms from the more aggressive ones, and to evaluate the results of the medical, surgical and schlerotherapical treatments, from the efficiently, functional, instrumental and aesthetically point-of-view
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
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