1,720,995 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
Awake video-assisted pleural decortication for empyema thoracis.
No full textOBJECTIVE:
To evaluate feasibility, technical features and results of video-assisted pleural decortication for empyema thoracis performed in awake patients.
METHODS:
This retrospective analysis involved a cohort of 19 patients (median age: 58 years) undergoing awake video-assisted thoracoscopic pleural decortication under epidural anaesthesia (N=15) or paravertebral blocks (N=4) between March 2004 and September 2008. Baseline and perioperative data including degree of postoperative lung re-expansion at 48 h, hospital stay, morbidity rate and daily fluid loss were recorded. In addition, intra- and perioperative changes in main pathophysiological variables PaO(2)/FiO(2) ratio, PaCO(2), mean arterial pressure and heart rate were analysed.
RESULTS:
Origin of the empyema was parapneumonic (N=14), post-traumatic (N=3) and cancer related (N=2). All patients underwent previous conservative management. The duration of the symptoms averaged 35 days (quartile range (QR): 28-40). Co-morbidities included chronic obstructive pulmonary disease (COPD) (N=4), HIV infection (N=1), diabetes mellitus (N=2) and cirrhosis (N=1). Operation was performed videothoracospically in 15 patients whereas four patients with major pleural thickening underwent awake lateral thoracotomy. Operative time averaged 50 min (QR: 40-70). Perioperative data analysis showed no intra-operative deterioration in arterial oxygenation (median-Delta: 0 mm Hg, QR: -5/+9, P=0.6). Transient permissive hypercapnia (<55 mm Hg) developed in three patients with no need of conversion to general anaesthesia. Median pain level assessed by a visual analogue score (VAS) 1h postoperatively was 4 (QR: 2-5), and it was significantly reduced on postoperative day 1 (median 3, QR: 2-4, P=0.03). There was neither mortality nor major morbidity. Hospitalisation averaged 6 days (QR: 5-7). At postoperative chest X-ray, lung re-expansion was rated as complete in 16 patients, satisfactory in (>80%) two patients and unsatisfactory in a 86-year-old patient with pleural mesothelioma who has the chest drain still in place 5 months after surgery. No patient had recurrence of the empyema at subsequent follow-ups.
CONCLUSIONS:
In our study, awake video-assisted pleural decortication proved feasible and resulted in satisfactory lung re-expansion in 95% of the patients. We hypothesise that spontaneous ventilation facilitated both identification of the correct plane and dissection, thus resulting in lesser surgical injury on the underlying lung
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
Surgical pneumothorax under spontaneous ventilation-effect on oxygenation and ventilation
Full text linkSurgical pneumothorax allows obtaining comfortable surgical space for minimally invasive thoracic surgery, under spontaneous ventilation and thoracic epidural anesthesia, without need to provide general anesthesia and neuromuscular blockade. One lung ventilation (OLV) by iatrogenic lung collapse, associated with spontaneous breathing and lateral position required for the surgery, involves pathophysiological consequences for the patient, giving rise to hypoxia, hypercapnia, and hypoxic pulmonary vasoconstriction (HPV). Knowledge of these changes is critical to safely conduct this type of surgery. Surgical pneumothorax can be now considered a safe technique that allows the realization of minimally invasive thoracic surgery in awake patients with spontaneous breathing, avoiding the risks of general anesthesia and ensuring a more physiological surgical course
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
The comparing of ultrasound-guided techniques:sciatic block with continous lumbar plexus block or continous femoral nerve block for aneshtesia and analgesia of total knee replacement
Full text linkAbstract: Background and Aims: This double blind prospective randomized clinical trial evaluated the efficacy and safety of continuous ultrasound-guided lumbar plexus block compared to continuous ultrasound-guided femoral nerve block, in the intra-operative and postoperative periods after total knee replacement.
Methods: Forty ASA I-III patients were randomized to receive: continuous femoral block (n= 20, 30 ml of ropivacaine 5 mg/ml) or continuous lumbar plexus block (n= 20, 30 ml of ropivacaine 5 mg/ml) both in association with single injection sciatic nerve block. All patients received continuous infusion of 2 mg/ml of ropivacaine at 8 ml/h for 48 hours and intra- venous morphine for patient-controlled analgesia. Primary outcomes were intra-operative sufentanil consumption and verbal analogue scale (VAS) score at rest at 24h follow up.
Results: Intra-operative sufentanil consumption was higher in the femoral block (FEM) group compared to the lumbar plexus block (PSOAS) group (FEM: 10.00 (10.00, 17.50) μg; PSOAS: 2.50 (0.00, 10.00) μg. p= 0.002).
Obturator motor blockade occurred more frequently in the PSOAS group (70%) than in the FEM group (40%) (p=0.1); however, we found no differences in sensory blockade (p=0.6).
VAS at rest was similar in the two groups at 24h postoperatively (FEM: 29.50 ± 14.74 mm; PSOAS: 25.60 ±17.42 mm. p=0.4), and throughout the follow-up period. No differences were detected in pain scores during physiotherapy.
Conclusion: Continuous femoral and lumbar plexus blocks, both in association with sciatic nerve block, provided similar VAS scores at 24h, and throughout the follow-up period; intra-operative sufentanil consumption was, however, lower in the lumbar plexus block group
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