1,721,036 research outputs found
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
Functional and clinical evaluation of innovative endovascular therapeutics for the treatment of critical limb ischemia
No full textLa maladie vasculaire périphérique concerne plus de 20% des occidentaux de plus de 80 ans. Son stade le plus grave, appelé ischémie critique du membre inférieur, est défini par la présence de douleur au repos, d'ulcères ischémiques ou de gangrène attribuables à la maladie artérielle occlusive. Sans traitement approprié, l'ischémie critique du membre inférieur mène à l'amputation et est associée à une morbidité et une mortalité élevée. L'étude randomisée Basil a démontré que l'angioplastie transluminale percutanée est une alternative au pontage chirurgical pour le traitement de la maladie artérielle périphérique des patients en ischémie critique dont l'espérance de vie est limitée, et présentant des comorbidités et/ou des contre-indications chirurgicales. L'amélioration clinique et la prévention des amputations majeures sont des éléments cruciaux pour évaluer l'efficacité de toutes les approches thérapeutiques de l'ischémie critique chronique. Ces données confirment la nécessité d'obtenir des résultats endovasculaires durables pour améliorer le devenir à long terme des patients en ischémie critique des membres inférieurs. Plusieurs stratégies peuvent être envisagées telles que l'amélioration de la sélection des patients à traiter par évaluation de la perfusion du pied ou encore l'utilisation de dispositifs innovants et de thérapies alternatives. L'évaluation fonctionnelle et clinique de ces nouvelles approches thérapeutiques endovasculaires pour le traitement de l'ischémie critique du membre inférieur sont au coeur de ce projet de thèse : Première partie : Mise au point d'un nouveau modèle animal pour l'évaluation de l'ischémie critique chez le lapin, qui soit la plus proche de la physiopathologie de l'ischémie chronique des membres inférieurs. Ce modèle a été créé par une approche percutanée miniinvasive en utilisant l'embolisation des artères de la patte avec des particules calibrées et permettra une meilleure compréhension de la physiopathologie de la maladie, l'évaluation des nouveaux méthodes diagnostiques et thérapeutiques. Deuxième partie : Evaluation de la perfusion tissulaire en Résonance Magnétique sur un modèle animal par DCE-RM pour caractériser l'extension et la distribution spatiale de l'ischémie dans les muscles du mollet d'un modèle lapin d'ischémie critique. Cette expérience préliminaire pourra servir de base pour une future évaluation chez les patients avec une ischémie critique. Troisième partie : création percutanée d'une fistule artérioveineuse distale dans le cas d'une ischémie critique comme méthode de traitement alternative chez les patients ou un traitement endovasculaire a échoué pour une maladie étendue aux vaisseaux du pied et à la microcirculation. L'objectif de ce travail est d'évaluer la sécurité et l'efficacité de cette technique chez les patients présentant une ischémie critique considérés comme non candidats à un geste de revascularisation chirurgicale ou endovasculaire conventionnel. Quatrième partie : Evaluation de la sécurité et de l'efficacité du ballon actif pour le traitement de lésions distales chez les patients avec une ischémie critique pour limiter le taux de resténose après un geste d'angioplastie des vaisseaux jambiers. Cinquième partie Utilisation des ultrasons intravasculaire a bas énergie et haute fréquence pour modifier la composition de la plaque athéromateuse calcifié en lésions distaux chez des patients avec une ischémie critique au but d'améliorer les résultats de l'angioplastie.Peripheral vascular disease affects more than 20% of Westerners over 80 years of age. The most severe stage, known as critical limb ischemia, is defined as the presence of resting pain, ischemic ulcers or gangrene due to occlusive arterial disease. Without appropriate treatment, critical limb ischemia leads to amputation and is associated with high morbidity and mortality. The randomized Basil study has demonstrated that percutaneous transluminal angioplasty is an alternative to surgical bypass for the treatment of peripheral arterial disease in critically ischemic patients with limited life expectancy, comorbidities, and / or -surgical indications. Clinical improvement and prevention of major amputations are critical elements in evaluating the efficacy of all therapeutic approaches to chronic critical ischemia. These data support the need for sustained endovascular outcomes to improve the long-term outcome of patients with critical limb ischemia. Several strategies can be envisaged, such as improving the selection of patients to be treated by evaluation of the foot perfusion or the use of innovative devices and alternative therapies. The functional and clinical evaluation of these new endovascular therapeutic approaches for the treatment of critical limb ischemia are at the heart of this thesis project: Part 1: Development of a new animal model for the assessment of critical limb ischemia in rabbits, which is closest to the pathophysiology of chronic lower limb ischemia. This model was created by a miniinvasive percutaneous approach using embolization of the paw arteries with calibrated particles and will allow a better understanding of the pathophysiology of the disease, evaluation of new diagnostic and therapeutic methods. Second part: Evaluation of tissue perfusion in Magnetic Resonance on an animal model by DCE-RM to characterize the extension and spatial distribution of ischemia in the calf muscles of a rabbit critical ischemia model. This preliminary experiment may serve as a basis for future evaluation in patients with critical limb ischemia. Part 3: Percutaneous creation of a distal arteriovenous fistula in the case of critical limb ischemia alterantive treatment in patients where endovascular treatment failed for an extended disease of the foot vessels and microcirculation. The aim of this work is to evaluate the safety and efficacy of this technique in patients with critical ischemia, who are considered non-candidates for conventional surgical or endovascular revascularization. Part 4: Evaluation of the safety and effectiveness of the drug eluting balloon for the treatment of distal lesions in patients with critical limb ischemia to limit the rate of restenosis after percutaneous angioplasty. Part 5 Use of low energy and high frequency intravascular ultrasound to modify calcified atheromatous plaque composition in distal lesions in patients with critical limb ischemia to improve angioplasty outcome
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
Efficacy of a Drug-Eluting Stent Versus Bare Metal Stents for Symptomatic Femoropopliteal Peripheral Artery Disease: Primary Results of the EMINENT Randomized Trial.
Full text linkBACKGROUND
A clear patency benefit of a drug-eluting stent (DES) over a bare metal stent (BMS) for treating peripheral artery disease of the femoropopliteal segment has not been definitively demonstrated. The EMINENT study (Trial Comparing Eluvia Versus Bare Metal Stent in Treatment of Superficial Femoral and/or Proximal Popliteal Artery) was designed to evaluate the patency of the Eluvia DES (Boston Scientific, Marlborough, MA), a polymer-coated paclitaxel-eluting stent, compared with BMS for the treatment of femoropopliteal artery lesions.
METHODS
EMINENT is a prospective, randomized, controlled, multicenter European study with blinded participants and outcome assessment. Patients with symptomatic peripheral artery disease (Rutherford category 2, 3, or 4) of the native superficial femoral artery or proximal popliteal artery with stenosis ≥70%, vessel diameter of 4 to 6 mm, and total lesion length of 30 to 210 mm were randomly assigned 2:1 to treatment with DES or BMS. The primary effectiveness outcome was primary patency at 12 months, defined as independent core laboratory-assessed duplex ultrasound peak systolic velocity ratio ≤2.4 in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesion. Primary sustained clinical improvement was a secondary outcome defined as a decrease in Rutherford classification of ≥1 categories compared with baseline without a repeat velocity ratio ≤2.4 in the absence of clinically driven target lesion revascularization. Health-related quality of life and walking function were assessed.
RESULTS
A total of 775 patients were randomly assigned to treatment with DES (n=508) or commercially available BMS (n=267). Baseline clinical, demographic, and lesion characteristics were similar between the study groups. Mean lesion length was 75.6±50.3 and 72.2±47.0 mm in the DES and BMS groups, respectively. The 12-month incidence of primary patency for DES treatment (83.2% [337 of 405]) was significantly greater than for BMS (74.3% [165 of 222]; P<0.01). Incidence of primary sustained clinical improvement was greater among patients treated with the DES than among those who received a BMS (83.0% versus 76.6%; P=0.045). The health-related quality of life dimensions of mobility and pain/discomfort improved for the majority of patients in both groups (for 66.4% and 53.6% of DES-treated and for 64.2% and 58.1% of BMS-treated patients, respectively) but did not differ significantly. At 12 months, no statistical difference was observed in all-cause mortality between patients treated with the DES or BMS (2.7% [13 of 474] versus 1.1% [3 of 263]; relative risk, 2.4 [95% CI, 0.69-8.36]; P=0.15).
CONCLUSIONS
By demonstrating superior 1-year primary patency, the results of the EMINENT randomized study support the benefit of using a polymer-based paclitaxel-eluting stent as a first-line stent-based intervention for patients with symptomatic peripheral artery disease attributable to femoropopliteal disease.
REGISTRATION
URL: https://www.
CLINICALTRIALS
gov; Unique identifier: NCT02921230
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Etude des effets antitumoraux des traitements intra-artériels hépatiques (chimioembolisation et thérapie par gène suicide) : rôle en imagerie per-opératoire : évaluation préclinique et clinique
No full textChez les patients atteints cancers colorectaux, les métastases hépatiques (CRCLM) sont une des principales causes de décès. Elles surviennent chez 50-75% des patients au cours de la maladie. Les traitements intra-artériels pour CRCLM ont conduit à des progrès continus; mais ces traitements restent limités par leur tolérance et leur efficacité. Nous avons exploré deux voies différentes pour essayer d'améliorer les résultats des traitements intra-artériels. La première consiste à optimiser la technique d'imagerie peropératoire, visant à anticiper la réponse tumorale. La seconde consiste à développer une nouvelle approche basée sur une thérapie par un gène suicide par voie intra-artérielle. En 1ière partie, nous avons exploré la réponse à la chimio-embolisation (TACE) suivant diverses approches en utilisant le Cone BeamCT (CBCT). Nous avons démontré d'abord la faisabilité de la segmentation tumorale avec un logiciel semi-automatique en IRM puis appliqué la même méthode à un modèle de tumeur VX2 du foie de lapin. Nous avons montré une forte corrélation de la taille de la tumeur entre le CBCT et Scanner (rho = 0,993, p <.001), et entre le CBCT et l'analyse anatomopathologique (rho = 0,996, p <.001. Le CBCT a un biais minimal (0,3 cm3), et une haute précision (0,674) dans la mesure des tumeurs. Puis, nous avons axé notre travail sur la quantification du rehaussement tumoral avant et après TACE; en tant que biomarqueur de substitution de la réponse tumorale. Le CBCT double phase a été utilisée en premier, montrant qu'une importante diminution de l'atténuation des tumeurs neuroendocrine est quantifiable après injection de particules emboligènes et qu'un effet micro-embolique notable était observable. En revanche dans une autre étude, le CBCT double phase n'a pas démontré son utilité dans la détection de CRCLM par un manque de sensibilité et spécificité(Se.58% Sp. 51%). Nous avons alors orienté notre recherche sur l'évaluation intra-procédurale de la perfusion tumorale. Dans ce travail, la valeur initial du volume sanguin tissulaire (PBV) était fortement corrélée à la réponse tumorale après TACE (rho = -0,8587; p = 0,00001). Nous prouvons que, l'augmentation de 1 ml / 1000 ml du volume sanguin de la tumeur avant la TACE conduit à une diminution de 0.54 mm du diamètre de la tumeur sur l'imagerie scanner à 2 mois. De plus, les patients avec une diminution de 1% en PBV après DEBIRI ont une probabilité de 10% d'observer une réponse tumorale (OR = 0,9, 95% CI intervalle: [0,81 à 1]; p = 0,0493). En conclusion de cette 1ière partie, une étude prospective plus large permettrait d'évaluer prospectivement la réponse tumorale basé sur PBV, permettant de sélectionner les répondeurs et de proposer aux non répondeurs un traitement local alternatif. Dans la 2nde partie, grâce à une forte collaboration avec l'équipe INSERM U 1147, nous avons mis au point un nouveau traitement intra-artériel basée sur une thérapie par gène suicide. Ou des cellules souches mésenchymateuses transduites par le gène mutant codant pour le cytochrome CYP2B6TM sont injectées dans l'artère hépatique. Nos travaux in vivo sur la tumeur hépatique VX2 du lapin montrent une différence significative du volume de la tumeur après traitement entre les groupes de contrôle et test. La nécrose de la tumeur était significativement plus élevée chez les lapins recevant la thérapie par gène suicide (78% de la surface totale de la tumeur) par rapport aux animaux témoins (22% de la surface totale de la tumeur (p = 0,006). Ces résultats nécessitent d'autres expérimentations qui sont en cours (documentation plus précise de la toxicité, des doses optimales) En résumé, dans cette thèse, nous montrons la valeur du CBCT dans l'évaluation de la réponse des CRCLM à TACE et nous avons élargi le champ des traitements intra-artériels une nouvelle thérapie par gène suicide qui semble prometteuse.Colorectal cancer liver metastases (CRCLM) are a leading cause of death. They occur in 50 - 75% of patients during the course of the disease. Intra-arterial treatments for CRCLM have led to continuous progress; but these treatments still face significant limitations regarding tolerance and results. We explored two different avenues in trying to improve the results of intra-arterial treatment. The first one consists in optimizing the intraprocedural imaging technique aiming at anticipating the tumoral response. The second one consists in developing a completely new approach based on so called "gene directed enzyme prodrug therapy" (GEPD). As a 1st part, we explored the intraprocedural response to chemo-embolization based on various approach using C-arm CBCT. We first demonstrated the feasibility of tumor segmentation with semi-automatic software on MRI image and then apply the same method a VX2 liver tumor model. We found a strong correlation of tumor size between C-arm CBCT and CT scan (rho = 0.993, p < .001) but also between CBCT and pathology (rho = 0.996, p < .001). In addition, we found a minimal bias (0.3 cm3), and high precision (0.674) when measuring tumors with C-arm CBCT. Since the C-arm CBCT precision was demonstrated, the next work was focused on the quantification of tumor enhancement before and after trans-arterial chemo-embolization (TACE); as a surrogate biomarker of tumor response with the goal to predict tumor response at an earlier stage. Dual-phase C-arm CBCT was first used, showing significant neuroendocrine tumor enhancement decrease after embolic injection accounting for a noticeable micro-embolic effect at the tumor capillary bed level. In another study, Dual-phase C-arm CBCT failed to demonstrate its utility in CRCLM detection because of a lack of accuracy (Sp.58% Se. 51%). We then orientated our search on intraprocedural evaluation of the parenchymal blood volume (PBV). In this work we showed that initial PBV was strongly correlated to tumor shrinkage after chemoembolization (rho=-0.8587; p=0.00001). Moreover the increase of1 ml/1000ml in the blood volume of the tumor before TACE leads to a decrease of 0.54mm in the diameter change of the tumor. Finally, patients with a 1% decrease in PBV after DEBIRI had a 10% lower likelihood of achieving disease control (OR=0.9, 95% confidence interval CI: [0.81 - 1]; p=0.0493). In conclusion of this 1st part, we anticipate the need for a dedicated clinical study that would evaluate prospectively the tumoral outcome based on PBV, with possible triage of responding/non responding tumors PBV toward alternative liver directed technique. As the 2nd part, thanks to a strong collaboration with INSERM U 1147 team we developed a new intra-arterial treatment based on a suicide gene therapy consisting of an engineered gene coding for a mutated cytochrome responsible of the metabolism of a prodrug. This new approach uses transduced mesenchymal stem cells (MSCs) as carrier of the suicide gene. Our work consisted in in-vivo experiments in rabbit VX2 liver tumor and showed significant tumor volume difference between control and test groups associated to tumor necrosis significantly greater for rabbits receiving the GDEPT (78% of total tumor surface) compared with control animals (22% of total tumor surface (p=0.006). These findings deserve further confirmations which are underway (refine the strategy, document toxicities...). In summary, in this thesis we show the value of C-arm CBCT inassessing CRCLM response to chemoembolization and enlarge the scope of intra-arterial therapy to suicide genetherapies which appear promising
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