1,721,014 research outputs found
Imbalanced serum levels of Ang1, Ang2 and VEGF in systemic sclerosis : integrated effects on microvascular reactivity
No full textIntroduction and aim: Microangiopathy is a hallmark of systemic sclerosis (SSc). It is a progressive process from an early inflammatory and proangiogenic environment to insufficient microvascular repair with loss of microvessels. The exact underlying mechanisms remain ill-defined. Aim of the study was to investigate whether imbalanced angiopoietins/VEGF serum profile should be related in SSc to the altered microvascular reactivity characterized by aberrant angiogenesis and avascularity.
Materials and methods: Serum levels of Angiopoietin-1 (Ang1), Angiopoietin-2 (Ang2) and VEGF were measured by ELISA in 47 SSc patients and 27 healthy controls. Microvascular alterations were assessed by nailfold videocapillaroscopy (NVC).
Results: Serum concentrations of Angl were significantly lower [mean (S.D.): 21516.04 (11,441.035) pg/ml], and Ang2 significantly increased [25,89.55 (934.225) pg/ml] in SSc as compared with the control group [Ang1: 28,457.08 (10,431.905) pg/ml; Ang2: 1556.23 (481.255) pg/ml, p < 0.01, respectively], whereas VEGF did not differ significantly. The ratios of Ang1/Ang2 and Ang1/VEGF were significantly lower in SSc patients (8.346 +/- 4.523 and 95.17 +/- 75.0, respectively) than in healthy subjects (17.612 +/- 6.731 p < 0.000001 and 183.11 +/- 137.73; p = 0.004]. Formation of giant capillaries with vascular leakage and collapse was associated with significant increase in VEGF and concomitant Ang1 deficiency. Capillary loss was related to significant increase in VEGF with respect to those with preserved capillary number (395.12 +/- 256.27 pg/mL vs. 254.80 +/- 213.61 pg/mL) whereas elevated Ang2 levels induced more advanced capillary damage as indicated by the presence of the "Late" NVC pattern.
Conclusions: We found that serum levels of Ang1, Ang2 and VEGF are differentially expressed in SSc and altered Ang1/Ang2 profile might underlay the aberrant angiogenesis in SSc despite increase in VEGF. For the first time we identified that significant deficiency of Ang1 might be involved in early capillary enlargement, followed by collapse and lack of stable newly-formed vessels in VEGF-enriched environment, whereas Ang2 levels seem to increase later in disease progression and advanced microvascular damage ("Late" NVC pattern)
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
Plasma endothelial microparticles reflect the extent of capillaroscopic alterations and correlate with the severity of skin involvement in systemic sclerosis.
No full textIntroduction and aim Endothelial microparticles (EMPs) are membrane-coated vesicles shed from endothelial cells and are considered markers of the endothelial state. It has been shown that total numbers of circulating EMPs are increased in patients with systemic sclerosis (SSc), but their clinical correlations have not yet been investigated in detail. We aimed to assess possible relationships between circulating EMPs and clinical as well as laboratory features among SSc patients with special attention to possible association with alteration in microvascular morphology objectified on nailfold videocapillaroscopy and clinical signs of microvascular complications. Materials and methods The study included 47 SSc patients and 27 age- and sex-matched healthy controls. EMPs were identified with flow cytometry after staining platelet-poor plasma with combinations of fluorescent cell-specific monoclonal antibodies (anti-CD31, -51, -42b, -62E and Annexin V). The following types of EMPs were evaluated: total EMPs (CD31 +/CD42b −), activated EMPs (CD62E +/AnnV −,) and apoptotic EMPs (CD62E +/AnnV + or CD51 +). Clinical evaluation of patients was obtained, including nailfold videocapillaroscopy. Results All types of EMPs were significantly elevated in SSc patients as compared with healthy controls. We found significant inverse correlation between severity of skin involvement and values of total EMPs (r = − 0.32; p = 0.02) and their levels tended to be lower in SSc patients with digital ulcers when compared to those without ischaemic skin lesions (p = 0.09). Total EMPs and activated EMPs showed correlations with the number of ramified capillaries (r = − 0.40 and r = 0.37, respectively, p < 0.05 for both). Moreover, total EMPs inversely correlated with the severity of capillary loss (r = − 0.35, p < 0.05) and their levels were significantly lower in patients with late NVC pattern with respect to those with early microangiopathy (p < 0.05). On the other hand, active NVC pattern was characterized by strongly elevated levels of activated EMPs when compared to an early vascular alteration (p < 0.05). Conclusions Our results suggest that quantity and phenotype of circulating EMPs might indicate on molecular vascular damage with endothelial dysfunction and to reflect progressive loss of capillaries consequencing in microvascular insufficiency in SSc patient
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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