1,720,960 research outputs found
Honey Supplementation to Semen-Freezing Medium ImprovesHuman Sperm Parameters Post-Thawing.
No full textObjective: To evaluate the effect of honey supplemented to cryoprotectant medium on post-thaw sperm motility, concentration, morphology and agglutination.
Materials and methods:Thirty semen samples were collected from 30 infertile patients. After assessment of semen analysis, semen samples were divided into 3 aliquots (0.7ml for each) and mixed with 1 ml of cryopreservation solution (G1, control) alone, or enriched with 5% honey (G2) or with 10% honey (G3) for cryopreservation. Cryopreservation was done at -196°C in liquid nitrogen and thawing was performed after six months. Direct swim up technique was used for in vitro sperm preparation post-thawing. Sperm parameters were assessed and data were statistically analyzed pre- and post-thawing.
Results: Results appeared that the percentage of sperm motility for G1 and G2 groups were significantly reduced (P 0.05) were observed between G1 and G2 groups. Significant reduction (P < 0.05) was seen in the sperm concentration for all groups post-thawing as compared to pre-cryopreservation groups. After thawing the results reveal significant reduction (P < 0.05) in the sperm agglutination (%) for G3 group as compared to G1 and G2 groups.
Conclusion: The results of this study indicated that the supplementation of honey (10%) to cryoprotectant solution results in enhancement of sperm quality post-thawing
Effect of Cumulus cell co-culture and Protein Supplement on Success of in vitro Fertilization and Development of Pre-implanted Embryos in mice
Full text linkSuccessful oocyte fertilization and normal embryonic development of mice were considered the most important diagnostic criteria for the safety of materials and tools used for human in vitro fertilization and embryo transfer (IVF-ET). Therefore, we studied the influence of cumulus cells co-culture and protein supplement within culture medium on percentages of in vitro fertilization (IVF) and normal development of early stages of mouse embryo later. Oocytes were collected and treated with hyaluronidase to remove cumulus cells. Oocytes were divided into four groups namely: Group-1: Oocytes incubated within modified Earl’s medium (MEM) supplied with 10% inactivated bovine amniotic fluid as a protein source and cumulus cells; Group-2: Oocytes incubated with MEM supplied with cumulus cells only; Group-3: Oocytes incubated with MEM supplied with 10% inactivated bovine amniotic fluid only; and Group-4: Oocytes incubated with MEM free of both protein source and cumulus cells. For IVF, 5-6 oocytes were incubated with active spermatozoa under paraffin oil for 18-20 hours at 37° oC in 5% CO2. Percentages of IVF and embryonic development were then recorded. Best results for IVF and normal embryonic development were achieved from oocytes of Group-1 when compared to the other groups. As compared to Group-1, the percentage of IVF for Group-2 and Group-3 were decreased insignificantly and significantly (P<0.002), respectively. Significant (P<0.01) reduction in the percentages of IVF and normal embryonic development were reported in Group-4 as compared to Group-1. Therefore, it was concluded that the presence of cumulus cells co-culture and bovine amniotic fluid as a protein source within culture medium may have an important role on the fertilizing capacity of spermatozoa and oocytes and normal development of pre-implanted mouse embryo later
The detrimental effect of cigarette smoking on semen parameters and sperm plasma membrane integrity in infertile patients undergoing intra-uterine insemination
No full textThe present study was designed to assess the effect of cigarette smoking on semen parameters, hypo-osmotic swelling (HOS) test (%) and outcome of intra-uterine insemination (IUI). In this study, one hundred infertile males were involved and according to cigarette smoking were divided into 55 smokers and 45 non smoker infertile couples. From each male, semen samples were collected and the sperm parameters including sperm concentration, sperm motility, progressive sperm motility, normal sperm morphology, and HOS-test were evaluated according to standard World Health Organization (WHO) criteria. For IUI, the sperm prepared using direct swim-up technique through incubation for 30 minute in 5% CO2 at 37ºC. The results of the present study demonstrated that the sperm parameters, HOS-test (%) and IUI outcomes for non smoker infertile males was higher than smokers. In addition, the results of sperm parameters and HOS-test (%) for smokers were more deviated from normal range of criteria of WHO than non smokers. Non significant differences (P>0.05) in the sperm HOS-test were assessed between non smokers and smokers.From the results of the present study, it was concluded that the cigarette smoking have several impacts on sperm functions and integrity of plasma membrane, as well as sperm fertilizing ability. Further studies are recommended to assess the effect of cigarette smoking on DNA damage and embryo quality after IVF-ET
Influence of different concentrations of Sildenafil Citrate on histological parameters of mice epididymis
Full text linksildenafil citrate (SC) is widely used for the treatment of erectile dysfunction and maintains a sufficient erection for satisfactory sexual performance. Very limited literatures were published about effects of SC on histological changes of epididymes in human or laboratory animals. The aim of this study was to investigate the influence of different concentrations of SC for different administration periods on some histological parameters of mice epididymes. Seventy five male mice (7-8) weeks old, weighing (23-25)g were used in the present study. The possible effect of SC was tested through the treatment groups of mice with different doses of SC (2, 4, 8, 16)mg/Kg body weight, and for different periods (1, 3, 5) weeks. Histological examination of epididymes were carried out and compared with those belong to untreated group. Results revealed no significant differences (P>0.05) in epididymal weight, tubules diameters and thickness of epithelial layer between treated groups and control group. Conclusion in this study, SC has no effect on epididymis histolog
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
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