1,721,068 research outputs found
COMPLICANZE DELL'IPERCORTISOLISMO SUBCLINICO: RISCHIO DI INSORGENZA DI FRATTURE VERTEBRALI E POSSIBILE RUOLO DELL'ORMONE DELLA CRESCITA.
Full text linkTitle: Subclinical hypercortisolism’ s complications: vertebral fracture’s risk and possible role of GH deficiency.
In patients with adrenal incidentalomas (AI), subclinical hypercortisolism (SH) has been associated with vertebral fractures and reduction of bone mass and quality. Spinal deformity index (SDI) has been proposed as a surrogate index of bone quality. The incidence of vertebral fractures in AI patients is unknown.
Moreover, overt cortisol excess is known to be associated with blunted GH secretion that generally normalizes after successful surgery. Subclinical Hypercortisolism (SH), has been not associated with reduced GH secretion. Data about the GH reserve in SH patients after adrenalectomy are lacking.
Aim of this prospective, multicenter study is to evaluate, in AI patients, bone mass changes and vertebral fracture’s risk, and assess GH secretory reserve in a subgroup of AI patients without and with SH and, in these latter, before and after surgery.
In 104 patients (36 M, 68 F) at baseline, after 12 and 24 months pituitary-adrenal axis secretion and bone status were evaluated. We diagnosed SH in the presence of at least 2 out of urinary free cortisol (UFC) levels >70 μg/24h; serum cortisol levels after 1–mg dexamethasone (Dex) suppression test (1mg-DST) >3.0 μg/dL; ACTH levels <10 pg/mL in at least 2 out of 3 evaluations. On the basis of the presence of SH we divided patients into SH- and SH+ groups. We evaluated: bone mineral density (BMD) by Dual-energy X-ray Absorptiometry at lumbar spine and femoral neck; presence of vertebral fractures using the semi-quantitative visual assessment of spinal radiographs; SDI by summing the grade of deformity for each vertebra.
In AI 23 patients we also assessed GH secretion and reserve by GH Releasing Hormone+Arginine (GHRH-ARG) test and age-adjusted IGF1 levels (IGF1-SDS). On the basis of the presence or absence of SH patients were divided in SH+ (8F; 3M; age 58±6.1 yrs) and SH- (12F; age 62±8.3 yrs) group. Six out of eight SH+ patients, who underwent surgery, were re-evaluated after withdrawal of steroid substitutive therapy.
At the end of follow-up SH+ patients (27/104) showed an higher prevalence of vertebral fractures (81.5 %) as compared to baseline (48.1%; P= 0.021), and a worsening of SDI (1.39±2.83 vs 0.41±1.44; P=0.008 respectively) that was associated with the presence of SH regardless for age, gender, BMI, BMD, basal SDI and years since menopause (OR 11.92, 95%CI 4.0-35.5; P=0.001). In SH- patients the prevalence of vertebral fractures was not different between baseline (29.9%) and the end of follow-up (36.4%). The incidence of new vertebral fractures was higher in SH+ than in SH- group (48% vs 13%, P=0.001).
Among the 23 patients evaluated for GH secretion, the GH peak and the GH secretory response to GHRH-ARG (expressed as the area under the curve, GH-AUC) were lower in SH+ as compared to SH- patients (22.0±19.4 vs 42.6±27.9 ng/ml, P<0.05; 1931.4±1710.8 vs 3864.2±2294.4, P=0.03 respectively) without correlations with metabolic and adrenal function parameters. After adrenalectomy, in the six SH+ patients operated on, GH-AUC values tended to increase (1645.8±1032.9 pre-surgery; 3244.8±2207.5 post-surgery; P=0.072).
In conclusion, in AI patients subclinical hypercortisolism is associated with an increased risk to develop new vertebral fractures over time. The role of GH secretion, that appears to be decreased in these patients, should be evaluated in larger samples
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
Linee ferroviarie per alta velocità a 3 kV c.c.: predeterminazione della distorsione armonica nel sistema trifase di alimentazione
No full textA presentation is made in this article of a suitable methodology for the study of the predetermination of the harmonic distortion of the voltages and currents of the high voltage feed system of railway lines-for high speed electrified at 3 kV d.c. The illustration of the methodology is presented with applicative reference to the case of the new FS line Milan-Florence at present in the project phase. Lastly an analysis is made of the possibility of characterizing the stochastic variations of the harmonic currents due to the traction load on the basis of the average arithmetic values in pre-fixed time intervals and of the relative standard deviations, for the purpose of differentiating the disturbance in the feed system in terms of duration, also with a view to possible similar distinctions on the normative level
A new method for forecasting CO2 operation emissions along an infrastructure corridor
No full textIn evaluating the sustainability of a new transport infrastructure, an important aspect is the reduction of
CO2 emissions that might be produced due to the modal shift. To that end, this article proposes a model
based upon the simulation method (in order to determine the specific consumption of the vehicles) and the
scenario method (for the prediction of the future demand of traffic). The model has been tested on the case
study of the Brenner Corridor. The evaluation is on how the new HC railway line will affect freight transport
in various future scenarios relating to 2030, taking into consideration the consequences in terms of traffic
redistribution on existing transport infrastructures (the historical railway line and the highway). If compared
to the work not being realized (the “minimum” scenario), the results reveal that CO2 emissions can increase
of about 80 kt (the “trend” scenario), or decrease of approximately 230 kt (the “consensus” scenario)
according to the political decisions that accompany the realization of the new line. In addition, the method
makes it possible to determine the specific emissions that are necessary to transport one metric ton of freight
along the entire corridor by the different transport modes. Finally, the transfer of freight from road to rail
is quantified that is necessary to compensate the emissions originating from the construction of the work
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
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