1,720,954 research outputs found
Luteal Phase Ovarian Stimulation May Improve Oocyte Retrieval and Oocyte Quality in Poor Ovarian Responders Undergoing In Vitro Fertilization: Preliminary Results from a Single-Center Prospective Pilot Study
No full textIntroduction: Luteal phase ovarian stimulation
(LPOS) has been proven a feasible protocol for
infertile patients. High progesterone level in the
luteal phase could physiologically inhibit premature
luteinizing hormone surge, from which
poor ovarian responders (PORs) could obtain
benefits. Therefore, we aimed to compare clinical
outcomes between LPOS and follicular phase
ovarian stimulation (FPOS) protocol in PORs
undergoing in vitro fertilization (IVF).
Methods: This prospective pilot study was performed
at one tertiary center from January 2016
to October 2017. A total of 60 PORs who met
Bologna criteria and undergoing IVF were
enrolled. Thirty PORs were allocated to the
LPOS group and 30 PORs were allocated to the
FPOS group. Basic characteristics, cycle characteristics,
and pregnancy outcomes were compared
between the two groups.
Results: The length of stimulation was significantly
longer in the LPOS group than in the
FPOS group. The numbers of retrieved oocytes,
metaphase II oocytes, fertilized oocytes, and
day-3 embryos were significantly higher in the
LPOS group than in the FPOS group. Conversely,
we could not find any significant difference for clinical pregnancy rate, ongoing
pregnancy rate, abortion rate, and cancellation
rate. The multivariate analysis showed that only
LPOS (p = 0.007) was significantly associated
the possibility to retrieve three or more oocytes,
whereas basal follicle-stimulating hormone
(FSH)\8 IU/l (p = 0.103) and antral follicle
count (AFC) C 3 (p = 0.143) did not significantly
affect this event.
Conclusion: LPOS allows improved oocyte
retrieval and oocyte quality in PORs with
respect to FPOS, despite comparable pregnancy
outcomes. LPOS may be considered a feasible
option for oocytes accumulation in PORs.
Trial Registration: ClinicalTrials.gov identifier,
NCT0323883
Dehydroepiandrosterone (DHEA) supplementation improves in vitro fertilization outcomes of poor ovarian responders, especially in women with low serum concentration of DHEA-S: a retrospective cohort study
Full text linkBackground: Dehydroepiandrosterone (DHEA) is now widely used as an adjuvant for in vitro fertilization (IVF)
cycles in poor ovarian responders (PORs). Several studies showed that DHEA supplementation could improve IVF
outcomes of PORs. However, most of the PORs do not respond to DHEA clinically. Therefore, the aim of this study
is to confirm the beneficial effects of DHEA on IVF outcomes of PORs and to investigate which subgroups of PORs
can best benefit from DHEA supplementation.
Methods: This retrospective cohort study was performed between January 2015 and December 2017. A total of
151 PORs who fulfilled the Bologna criteria and underwent IVF cycles with the gonadotropin-releasing hormone
antagonist protocol were identified. The study group (n = 67) received 90 mg of DHEA daily for an average of
3 months before the IVF cycles. The control group (n = 84) underwent the IVF cycles without DHEA pretreatment.
The basic and cycle characteristics and IVF outcomes between the two groups were compared using independent
t-tests, Chi-Square tests and binary logistic regression.
Results: The study and control groups did not show significant differences in terms of basic characteristics. The study
group demonstrated a significantly greater number of retrieved oocytes, metaphase II oocytes, fertilized oocytes, day 3
embryos and top-quality embryos at day 3 and a higher clinical pregnancy rate, ongoing pregnancy rate and live birth
rate than those measures in the control group. The multivariate analysis revealed that DHEA supplementation was
positively associated with clinical pregnancy rate (OR = 4.93, 95% CI 1.68–14.43, p = 0.004). Additionally, in the study
group, the multivariate analysis showed that serum dehydroepiandrosterone-sulfate (DHEA-S) levels < 180 μg/dl were
significantly associated with a rate of retrieved oocytes > 3 (OR = 5.92, 95% CI 1.48–23.26, p = 0.012).
Conclusions: DHEA supplementation improves IVF outcomes of PORs. In PORs with DHEA pretreatment, women with
lower DHEA-S level may have greater possibility of attaining more than 3 oocytes
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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