1,720,968 research outputs found
Effects of metformin treatment on whole-body and splanchnic amino acid turnover in mild type 2 diabetes.
No full textEffects of metformin treatment on whole-body and splanchnic amino acid turnover in mild type 2 diabetes.
No full textThe effects of metformin therapy on whole body and splanchnic amino acid turnover are not known. Therefore, we have studied fasting and postprandial phenylalanine kinetics in type 2 diabetic subjects (non-insulin-dependent diabetes mellitus), previously treated with diet only, both before and after 4 weeks of either metformin (850 mg twice a day) (n = 11) or placebo administration (n = 6). Phenylalanine kinetic was evaluated by means of a multiple isotope technique: tritiated phenylalanine was infused i.v., whereas carbon-labeled phenylalanine was incorporated into a chemically-defined meal. Compared with placebo, metformin administration decreased both fasting (from 162 +/- 17 to 141 +/- 20 mg/dl) and postprandial (from 217 +/- 20 to 164 +/- 20 mg/dl) glucose concentrations (P < 0.05-P < 0.01). Fasting insulin concentrations were unaffected, but postmeal insulin tended to be lower (P < 0.06) after metformin. Compared with the pretreatment period, metformin administration did not change total phenylalanine rate of appearance (fasted state, 0.74 +/- 0.10 vs. 0.71 +/- 0.08 mumol/kg.min; fed state, 0.77 +/- 0.10 vs. 0.75 +/- 0.08 mumol/kg.min, respectively), dietary and endogenous phenylalanine rate of appearance, dietary phenylalanine oxidation, and splanchnic uptake, similar to what was observed in the placebo group. Our data indicate that, at least after a 4-week treatment, metformin does not affect fasting and postprandial protein turnover, as indicated by phenylalanine data, in subjects with mild non-insulin-dependent diabetes mellitus
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
Leucine and phenylalanine kinetics during mixed meal ingestion: a multiple tracer approach.
No full textTo estimate whole body and splanchnic metabolism of dietary amino acids, phenylalanine and leucine kinetics were determined simultaneously in six normal volunteers before and during the constant administration of a complete mixed meal, employing multiple tracers of these amino acids. L-[5,5,5-2H]leucine and L-[2,6-3H]-phenylalanine were infused intravenously; L-[1-13C]leucine and L-[1-14C]phenylalanine were administered orally with the meal. During the meal, steady-state leucine concentration rose from 136 +/- 6 to 190 +/- 14 mumol/l (P less than 0.01), phenylalanine from 44 +/- 4 to 61 +/- 6 mumol/l (P less than 0.01), total leucine rate of appearance (Ra) from 1.29 +/- 0.03 to 1.77 +/- 0.07 (P less than 0.01, +37 +/- 3%), and phenylalanine Ra from 0.73 +/- 0.05 to 0.80 +/- 0.07 mumol.kg-1.min-1 (P less than 0.05, +8 +/- 3%). Splanchnic uptake of dietary phenylalanine was greater (P less than 0.001) than that of leucine (58 +/- 4 vs. 25 +/- 4%, respectively), 44 +/- 3% of circulating leucine derived from the diet vs. 20 +/- 2% of circulating phenylalanine (P less than 0.01). Endogenous leucine and phenylalanine Ra were significantly suppressed (P less than 0.05). In summary: 1) splanchnic uptake of dietary phenylalanine is onefold greater than that of leucine; 2) dietary contribution to systemic phenylalanine Ra is about half of that to leucine Ra; and 3) endogenous appearance of both leucine and phenylalanine after the meal is suppressed. In conclusion, splanchnic metabolism of dietary leucine and phenylalanine differs markedly and can be quantitated in vivo without catheterization
Fasting and postmeal phenylalanine metabolism in mild type 2 diabetes.
No full textWe have investigated postabsorptive and postprandial phenylalanine kinetics in non-obese type 2 diabetic patients [non-insulin-dependent diabetes mellitus (NIDDM)], using a double-isotope technique and the constant oral administration of a synthetic mixed meal. Fasting and postmeal glucose levels were increased (P < 0.01) in NIDDM (165 +/- 16 to 226 +/- 24 mg/dl), with respect to normal controls (85 +/- 3 to 102 +/- 6 mg/dl). Fasting insulin concentrations were comparable in NIDDM (13 +/- 2 microU/ml) and in normals (12 +/- 2 microU/ml), but after the meal it increased less (P < 0.07) in NIDDM vs. normals (to 36 +/- 5 vs. 56 +/- 12 microU/ml, respectively; P < 0.01 vs. basal for both). Postabsorptive phenylalanine rate of appearance (R(a)) in NIDDM (0.63 +/- 0.08 mumol.kg-1 x min-1) was comparable to that of controls (0.73 +/- 0.05 mumol.kg-1 x min-1, not significant). During the meal, total and endogenous phenylalanine R(a), splanchnic uptake, oxidation, and nonoxidative disposal of the ingested phenylalanine were also comparable in the two groups. These data indicate that fasting and postprandial kinetics of the essential amino acid phenylalanine are normal in NIDD
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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