1,721,035 research outputs found
Differential estrogen and antiestrogen responsiveness of the uterus during development in the fetal, neonatal and immature guinea pig.
No full textAfter 2-day estradiol treatments, wet weight increases in fetuses, newborns and immature guinea pigs by (means +/- SEM) 75 +/- 4%, 170 +/- 16% and 234 +/- 25%, respectively; while after 3-day tamoxifen treatments they are 83 +/- 11%, 157 +/- 35% and 127 +/- 9%, respectively. During the same periods, estradiol increases the uterine content of DNA while the effect of tamoxifen on uterine DNA decreases throughout development. Histologically, both estradiol and tamoxifen induce in the fetus an increase in the size of the stroma and myometrium. Estradiol or tamoxifen, respectively, increase the luminal epithelial cell height by (means +/- SEM) 95 +/- 2% and 67 +/- 2% in fetuses, 286 +/- 20% and 100 +/- 2% in newborns and 260 +/- 10% and 138 +/- 4% in immature animals. Luminal epithelial cell number increases in fetuses, newborns and immature animals by (means +/- SEM) 167 +/- 10%, 248 +/- 50% and 76 +/- 15%, respectively, after estradiol treatments and 160 +/- 20%, 69 +/- 15% and 17 +/- 5%, respectively, after tamoxifen treatments. Uterine epithelial growth invading the stroma was observed in both estradiol- and tamoxifen-treated fetuses. In neonatal or immature animals, estradiol increases the size and the number of endometrial glands, while tamoxifen has progressively less effects on endometrial glands and on the myometrium. It is concluded that: 1) the estradiol-induced uterotropic effect increases progressively in fetal, neonatal and immature animals; and 2) throughout development, tamoxifen has progressively weaker estrogenic properties than estradiol
ChemInform Abstract: Formation of the TcN Multiple Bond from the Reaction of Ammonium Pertechnetate with S‐Methyl Dithiocarbazate and Its Application to the Preparation of Technetium‐99m Radiopharmaceuticals.
No full textThe reaction of pertechnetate with the S-methyl ester of dithiocarbazic acid, H2N-NR-C(=S)SCH3 (R = H or CH3), in the presence of HCl and triphenylphosphine, affords the technetium(V) nitrido complex [TcNCl2(PPh3)2] in high yield. Derivatives of S-methyl dithiocarbazate of the type R1(R2)C=N-NR3-C(=S)SCH3, where R1 = o-C6H4OH, C6H5, or CH3, R2 = H or CH3, and R3 = H or CH3, behave as sources of N3- groups, giving rise to a variety of technetium complexes containing the Tc≡N multiple bond. These reactions apply equally well to the preparation of technetium-99m radiopharmaceuticals containing the Tc≡N group, at the non-carrier-added level of nuclear medicine
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
Anti-estrogens in fetal and newborn target tissues.
No full textThe antagonistic effects of progesterone and of the anti-estrogens, tamoxifen and nafoxidine, to estrogen responses were studied in the target tissues of fetal and newborn guinea pigs. In the fetal uterus, progesterone inhibits the stimulatory effect provoked by estradiol on uterine growth, on progesterone receptor and on the acetylation of nuclear histones. Progesterone also blocks the synthesis of new progesterone receptor protein in organ culture. Tamoxifen or nafoxidine (1 or 10 mg/kg/day injected to the mother for 3 days) provoke a uterotrophic effect similar to that of estradiol (1 mg/kg/day injected to the mother for 3 days) but these anti-estrogens have a limited effect on the progesterone receptor. Tamoxifen given together with estradiol antagonizes the effect of the estrogen on the acetylation of histones but the anti-estrogens do not block the effect of estradiol on uterine growth. Histological studies show that both estradiol and tamoxifen provoke a dramatic hypertrophic and hyperplastic effect particularly in the uterine epithelium. In the newborn uterus (6-day old), tamoxifen (s.c. injection of 0.6 micrograms/g body weight) and estradiol (injection of 30 ng/g body weight) provoke a similar uterotrophic effect and both have a limited effect on the progesterone receptor. In the fetal thymus estradiol provokes a selective decrease in the larger and actively proliferating lymphoid cells of the cortical zone. Tamoxifen has a similar effect but to a much lesser extent than estradiol. On the other hand, tamoxifen antagonizes the effect of estradiol on this fetal tissue. It is concluded that during fetal life progesterone antagonizes the effect of estradiol but tamoxifen can act as an agonist or an antagonist of estrogen action which is a function of the type of response or organ considered
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
La valutazione della forza muscolare nell’anziano fragile.
No full textIl lavoro si propone di studiare la forza muscolare nell'anziano, come valutarla nei vari setting assistenziali e come prevenire la sarcopenia nell'anziano fragile
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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