1,720,993 research outputs found
Modulation of inflammation and endothelial activation with spaceflight travel: tocotrienols as atheroprotective agents / Suhaila Abd Muid
Full text linkThe effects of immediate spaceflight travel on inflammation and endothelial activation in human endothelial cells (ECs) is not yet established. In addition, theexpression of these biomarkers in revived live ECs recovered from a spaceflight travel has not been reported so far. Endothelial activation is preventable. One of the major preventive strategies is the usage of antioxidants. Tocotrienols (TCTs) is a more potent antioxidant than tocopherol (TOC). However, the role of Tocotrienol enriched mixed fraction (TEMF) and pure TCT isomers as a potential potent antiatherosclerotic agent in human ECs compared to pure a-TOC is not well established.The anti-atherosclerotic mechanism of TCTs is also unclear. The objectives of this study were to investigate (i) the effects of spaceflight travel on the protein and gene expression of inflammation and endothelial activation, nuclear factor kappa B (NFkB) and endothelial nitric oxide synthase (eNOS) in human ECs compared to ground controls, (ii) the protein and gene expression of inflammation and endothelial activation, NFkB, signal transducer and activator of transcription-3 (STAT-3) and eNOS in revived live human ECs compared to matched controls (iii) the effects of TEMF, pure TCT isomers, and a-TOC on inflammation, endothelial activation, monocytes binding activity, NFkB and eNOS, and (iv) the most potent pure TCT isomers on the inhibition of the inflammation, endothelial activation, monocytes binding activity, NFkB and eNOS biomarkers in lipopolysaccharides (LPS) stimulated human ECs. The culture medium and ECs from post-spaceflight, revived
and corresponding controls were collected and measured for protein and gene expression of cytokines (IL-6 and TNF-a), adhesion molecules (ICAM-1, VCAM-1 and e-selectin), NFkB and/or STAT-3 and eNOS. Human umbilical vein endothelial cells (HUVECs) were incubated with various concentrations of TEMF, pure TCT isomers and a-TOC (0.3-10 |iM) together with, lipopolysaccharides (LPS) for 16 hours. Culture medium and cells were collected and measured for the protein and gene expression of cytokines, adhesion molecules, NFkB and eNOS. The immediate post-spaceflight cells showed enhanced expression of cytokine (IL-6), adhesion molecules (ICAM-1 and VCAM-1) and NFkB compared to ground controls. Following post spaceflight, the revived cells were shown to have increased expression of IL-6 , ICAM-1 and STAT-3. TEMF and pure TCT isomers reduce IL-6, ICAM-1, VCAM-1, e-selectin, monocytes binding activity, NFkB and induce eNOS expression. Area under the analysis revealed that pure TCT, particularly y- and 8-isomers have better reduction of inflammation and endothelial activation and greater eNOS increment than TEMF. Delta (8)-TCT is the most potent TCT isomers in terms of as an atheroprotective agent. Spaceflight travel leads to enhanced inflammation and endothelial activation and these remain elevated even after 3 months post spaceflight travel. This study provided a better understanding on the modulation of inflammation and endothelial activation associated with space travel and may direct future studies in the prevention of atherosclerosis in space travel. TEMF and pure TCT isomers exhibit anti-atherosclerotic properties with great potential as atheroprotective agents. The possible pathway for its anti-atherosclerotic activity is through the NFkB deactivation. a-TOC has inhibitory effects on the antiatherosclerotic properties of TCTs in TEMF
Effects of palm oil derived tocotrienol rich fraction (TRF) on coronary risk markers: in vitro and in vivo studies / Suhaila Abd Muid
Full text linkTocotrienol is one of the vitamin E compounds which have potent anti-oxidant activity leading to reduction in oxidative stress and inflammation. Oxidative stress and inflammation are now emerging as pivotal factors in the pathogenesis of atherosclerosis and coronary artery disease (CAD). However, optimal concentrations of palm oil derived tocotrienol rich fraction (TRF) that may lead to reduction of oxidative stress and inflammation in in vitro and in vivo studies are still unclear. The objectives of this study were to determine the optimal concentrations of TRF which leads to the highest antioxidant activity and reduction of inflammation markers in vitro and to study the effects of palm oil derived TRF vitamin E capsules (Palmvitee) contained low dose tocotrienol on oxidative stress in patients with non-familial hypercholesterolaemia (NFH). Antioxidant activities were assessed by Ferric thiocyanate (FTC), 1,1-diphenyl-2picrylhydrazyl (DPPH) radical scavenging activities and dichlorofluorescein diacetate (DCFHDA) assays. Supernatant of stimulated endothelial cells was measured for the production of inflammatory markers [e-selectin, p-selectin, soluble intercellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1) and inter leukin-6 (IL-6)]. Sixty-six patients with NFH (38 males, 28 females, age ± SD age = 46.9 ± 9.4 years) were recruited and randomised to 3 treatments arm, which were palmvitee 300 mg/day (NFHe), atorvastatin 10 mg/day plus placebo (NFHsp) or atorvastatin 10 mg/day plus palmvitee (NFHse). Fasting serum lipids (FSL), oxidised LDL (ox-LDL), malondialdehyde (MDA) and 8-epi-PGF2α were measured at baseline (BL) and 2 weeks, 12 weeks and 36 weeks post-randomisation. Normocholesterolaemic (NC) subjects were recruited in parallel. In the FTC assay, TRF at concentrations 10 and 100 µg/ml showed the highest percentage (%) of inhibition, 96.4 ± 0.2% and 96.3 ± 0.2% respectively. In the DPPH assay, optimal TRF concentration was observed at concentration 62.5 µg/ml with the highest % inhibition (85.2 ± 0.8%). Lowest % increase of DCF fluorescence production was shown by induced RAW 264.7 cells incubated with 88 µg/ml TRF concentration and it was significantly lower than DCF fluorescence produced by RAW 264.7 cells incubated with inducer (lipopolysaccharides and interferon gamma) alone , 95.0 ± 1.4% vs. 194 ± 18.5%, p<0.05. -The results from the DPPH and DCFHDA assay were consistent with the findings from the .FTC method which reported optimal TRF concentration within the range of 10-100 µg/ml, Optimal TRF concentrations leading to maximal inhibition of e-selectin , p-selectin, sICAM-1 , sVCAM-1 and IL-6 in stimulated endothelial cells were 0.8, 0.4, 0.8, 3.4 and 0.2 µg/ml, with percentage inhibition of 88.0 ±2.0%, 88.0 ±0.1%, 55.0 ±3.0%, 75.0 ±4.0% and 56.0 ±12.0%, respectively. NFHe group showed neutral effects on FSL, but reductions in MDA (p<0.005), ox-LDL (p<0.05) and 8-epi-PFGF2α (p<0.05) levels at 12 weeks compared to BL. NFHsp and NFHse groups showed similar reductions in 'Fe and LDL at 2 weeks (p<O.OOO 1) compared to BL. TO level was also reduced at 2 weeks in both NFHsp (p<O.O 1) and NFHse (p<0.005) groups compared to BL. NFHsp and NFHs
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
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
- …
