1,721,132 research outputs found
Twin to twin transfusion syndrome presenting at early stages: is there still a possibile role for amnioreduction.
No full textOBJECTIVE: To assess the rate of resolution or progression after first line treatment with amnioreduction and related outcome of pregnancies with twin-to-twin transfusion syndrome (TTTS) diagnosed at stages I-II.
METHOD: Data on 34 monochorionic diamniotic twin pregnancies presenting with TTTS at stage I-II before 26 weeks of gestation were collected retrospectively (1999-2006). All patients underwent at least one amnioreduction. The outcome and the results of neurological follow-up of surviving twins were analysed in relation to the regression or progression of the disease after treatment.
RESULTS: Fourteen cases (41%) resolved after treatment while 18 cases (53%) progressed. In two patients immediate complications occurred within one week after amnioreduction; at least one infant survived in 85.3% of cases and there was double survival in 58.8%. Double survival was significantly better in cases that regressed (85.7%) compared with those cases that progressed (44.4%). None of the surviving infants in the group of cases with regression showed major neurological abnormalities.
CONCLUSION: In our study, one-third of patients with stage I-II TTTS regressed after a single amnioreduction, and pregnancies with resolution of TTTS usually had a favourable outcome
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
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
Low-dose aspirin in prevention and treatment of intrauterine growth retardation and pregnancy-induced hypertension
No full textMeta-analysis of data from several controlled trials has shown that low-dose aspirin reduces the risk of pregnancy-induced hypertension (PIH) and intrauterine growth retardation (IUGR) in women at high risk of these disorders. We have assessed the efficacy of low-dose aspirin in women judged to be at moderate risk. Women were included on prophylactic criteria--age under 18 or over 40 years, mild or moderate chronic hypertension (diastolic pressure between 90 and 110 mm Hg), nephropathy with normal renal function and blood pressure, history of PIH or IUGR, and twin pregnancy--or therapeutic criteria--PIH or early signs of IUGR in current pregnancy. Eligible women were randomly assigned treatment with 50 mg aspirin daily until delivery (583) or no treatment (523); 18 and 46 women, respectively, were lost to follow-up. The groups were well matched for baseline characteristics. We found no differences between the no-treatment and aspirin groups in numbers of spontaneous (5 vs 2) or therapeutic (1 vs 2) abortions, stillbirths (14 vs 13), perinatal mortality (35.7 vs 28.6 per 1000 births), mean birthweight (2858 [SD 729] vs 2874 [795] g), proportion of infants with birthweights below the 10th centile (95 [18.3%] vs 117 [19.0%]), or births before 37 weeks' gestation (184 [35.6%] vs 209 [33.9%]). Nor did the groups differ in the frequency of PIH with or without proteinuria (51 [15.2%] vs 81 [19.3%]). There was no difference in mean birthweight between the treatment groups in separate analyses according to criteria for trial entry and week of gestation at randomisation. Our study gives little support to the notion that low-dose aspirin is beneficial in women at moderate risk of PIH or IUGR
Ruolo della velocimetria Doppler delle arterie uterine nelle gravidanze gemellari: esiste differenza tra gravidanze monocoriali e bicoriali?
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