1,720,987 research outputs found
Editorial Comment on: Effect of Laser Settings and Irrigation Rates on Ureteral Temperature During Holmium Laser Lithotripsy, an In Vitro Model by Wollin et al
Full text linkMinimally invasive PCNL-MIP
No full textMiniaturized percutaneous nephrolithotomy (mini-PCNL) has increased in popularity in recent years and is now widely used to overcome the therapeutic gap between conventional PCNL and less-invasive procedures such as shock wave lithotripsy (SWL) or flexible ureterorenoscopy (URS) for the treatment of renal stones. However, despite its minimally invasive nature, the superiority in terms of safety, as well as the similar efficacy of mini-PCNL compared to conventional procedures, is still under debate. The aim of this chapter is to present one of the most recent advancements in terms of mini-PCNL: the Karl Storz "minimally invasive PCNL" (MIP). A literature search for original and review articles either published or e-published up to December 2016 was performed using Google and the PubMed database. Keywords included: minimally invasive PCNL; MIP. The retrieved articles were gathered and examined. The complete MIP set is composed of different sized rigid metallic fiber-optic nephroscopes and different sized metallic operating sheaths, according to which the MIP is categorized into extra-small (XS), small (S), medium (M) and large (L). Dilation can be performed either in one-step or with a progressive technique, as needed. The reusable devices of the MIP and vacuum cleaner efect make PCNL with this set a cheap procedure. The possibility to shift from a small to a larger instrument within the same set (Matrioska technique) makes MIP a very versatile technique suitable for the treatment of almost any stone. Studies in the literature have shown that MIP is equally effective, with comparable rates of post-operative complications, as conventional PCNL, independently from stone size. MIP does not represent a new technique, but rather a combination of the last ten years of PCNL improvements in a single system that can transversally cover all available techniques in the panorama of percutaneous stone treatment
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
The new grasper-integrated single use flexible cystoscope for double J stent removal: evaluation of image quality, flow and flexibility
No full textBackground: A new single use digital flexible cystoscope (FC) Isiris α from Coloplast® with an incorporated grasper has been developed to perform double J stent removal. There is a lack of data regarding the comparison of image quality, flexibility and flow between classic cystoscopes and the new Isiris α. Materials and methods: Five different FC were used to compare the image quality, the field of view, the loss of flow and the deflection loss. Two standardized grids, three stones of different composition and a ruler’s image were filmed in four standardized different scenarios. These videos were shown to thirty subjects that had to evaluate them. Water outflow was measured in ml/sec in all devices with and without the grasper inside, instruments tip deflection was measured using a software. Results: In the subjective analysis of the image quality Isiris α was the second FC best scored. At 3 cm of distance, the field view of Isiris α was the narrowest. Comparing the water flow in the different FCs, we observed a water flow decrease in all cystoscopes when the grasper was loaded in the working channel. Isiris α deflection and flow increase when the grasper is activated. Conclusion: In terms of quality of vision and water flow, the FC Isiris α is comparable to the other digital FC tested. Field of view is narrower. The results displayed a valid alternative to the standard procedure for DJ removal
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
Laser fiber and flexible ureterorenoscopy: the safety distance concept
Full text linkINTRODUCTION The costs of flexible ureterorenoscopes (fURS) and their repair oblige the surgeon to know the proper handling of instruments. There is a lack of evidence in the literature about the safety distance that the laser fiber should have once out from the scope to avoid instrumental damages. MATERIAL AND METHODS We performed an in-vitro observational study. Seven fURS were tested. The distance from the laser fiber tip and the fURS camera was measured at the first appearance on the endoscopic screen and when the fiber was reaching one fourth of the screen. Secondly, to evaluate the impact of the Holmium laser bubble according to the different fiber distances, an assessment of the size and shape of the bubble created at the tip of the fiber with the laser activated was done recording the images with an High Speed Camera. RESULTS The first appearance on the screen of the laser tip is different in different scopes. In all the scopes when observed that when the laser fiber was at 1⁄4 of the screen the bubble was never touching the fURS tip. CONCLUSION Even if there is a big limitation of this study due the impossibility to measure and to evaluate the damage of the fURS tip surface, we observed that when the laser fiber tip reach 1⁄4 of the screen, the bubble generated by the laser activation is never rebounding on the camera of the scope preserving it from laser damages. We can define this position as the "safety distance"
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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