124,611 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
EVIDENCE OF UNIDIRECTIONAL PULSATILE FLOW IN THE UMBILICAL INTERARTERIAL ANASTOMOSIS
No full textBackground An anastomosis between umbilical arteries (UAS), located within 1–3 cm from the placental insertion, has been previously described at delivery and in utero. However, the prenatal investigation of this vessels is limited to case reports. We report a series of antenatal functional evaluation of this vessel. Method 41 women underwent a target ultrasonography to evaluate the blood flow characteristics of UAS and UAS anastomosis. The resistance index (RI) of the anastomosis and the UAS RI before and after the anastomosis was obtained. The direction of the blood flow in the anastomosis was determined by color Doppler evaluation. Results An anastomosis between the two stems of the UAS was present in 36 cases while a fusion of the two UAS was found in the remaining 5 cases. The median (range) gestational age at diagnosis was 33.1 weeks (25.5–40.1). The median (range) diameter of the anastomosis was 2.3 mm (1.3–7.1). The blood flow in the anastomosis was pulsatile with a median (range) RI of 0.62 (0.45–0.85). The difference between UAS RI was higher after than before the anastomosis [0.07 (0–0.3) vs. 0.04 (0–0.17), P = 0.051]. The anastomosis blood flow was always unidirectional. Conclusion During fetal life, the UAS anastomosis acts as a pressure‐equalizing system between UAS and the placental lobes
CERVICAL RIPENING WITH THE FOLEY CATHETER.
No full textObjective: To evaluate maternal and neonatal outcomes in a large series of patients undergoing cervical ripening with a Foley catheter. Methods: The database of the Labor and Delivery Unit of the University of a teaching. hospital in Italy was used to identify consecutive patients with a Bishop score (BS) of 4 or less who underwent pre-induction cervical ripening with a Foley catheter. The main outcome measures were clinical chorioamnionitis, endometritis, and suspected and culture-proven neonatal sepsis. Results: Of 602 women undergoing cervical ripening with a Foley catheter, 160 (26.6%) went into active labor without additional interventions. Oxytocin was administered immediately after removal of the Foley catheter in 188 (31.2%) of the women, and 254 (42.2%) required an application of prostaglandin E2 vaginal get. The cesarean delivery rate was 25.6%. The median time to delivery was 1469 min (range, 94-3350 min). Of the women who gave birth vaginally, 225 (50.2%) were delivered within 24 h. Clinical chorioamnionitis and postpartum endometritis occurred in 3 (0.5%) and 6 (1.0%) of the women, respectively. Neonatal sepsis was suspected in 4 (0.7%) of the newborns but blood culture results were negative in all cases. Conclusion: Transcervical use of the Foley catheter is safe for pre-induction cervical ripening, and the associated risk of maternal or perinatal infections is negligible. (C) 2006 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved
Rottura prematura delle membrane a 20-26 settimane di gestazione: outcome ostetrico e mortalità perinatale
No full textMisurazioni ecografiche del cordone ombelicale : nuove metodiche non invasive di diagnosi precoce di sofferenza fetale
No full textHemodynamic effects of betamethasone on growth-restricted fetuses with absent or reversed end-diastolic flow.
No full textAmniocenetesi e cerchiaggio d’emergenza nella terapia dell’incontinenza cervicale con prolasso delle membrane: esperienza di un anno presso la clinica ostetrica e ginecologica di Varese
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