1,721,020 research outputs found
Radiation-tailored xyloglucan-doxorubicin nanoparticles for cancer therapy
No full textPolysaccharides are long chains of monosaccharides linked by glycosidic bonds. They are widely utilized in biomedical applications, for tissue engineering and wound management, and as excipients of pharmaceutical formulations. In cancer therapy, the development of nanoscale drug delivery systems aims at addressing issues related to the low efficacy of chemotherapeutics and protein drugs due to poor solubility and stability, and to off-target effects that severely affect patients’ body conditions. Biocompatibility, availability of functional groups, amenability of chemical derivatisation and multifunctional conjugation with drugs and targeting ligands make polysaccharide nanoparticles interesting drug delivery devices for cancer treatment. Targeting and controlling the drug release at the tumour site are promising approaches to maximise the anti-tumour effects and reduce side-effects. Xyloglucan is a highly branched, hydrophilic polysaccharide composed of a -D-glucan main chain and -D-xylose branches, partially substituted by -D-galactoxylose. Xyloglucan extracted from tamarind seeds (TS-XG) is commercially available, non-toxic, biodegradable and FDA-approved as food additive. Due to the high molecular weight and tendency to associate in ribbon-like aggregates, aqueous colloidal dispersions of xyloglucan are characterised by relatively large nanoparticles with a broad size distribution. Gamma irradiation of either the colloidal dispersion of xyloglucan (XG) or the solid powder is a very effective and clean methodology to resize the molecular weight of the polysaccharide and reduce the particle size of its colloidal dispersions. When xyloglucan is irradiated as aqueous dispersion, irradiation causes extensive chain scission, with a dramatic reduction of molecular weight already at low doses (50-500 Gy). In contrast, when it is irradiated in the solid state, higher doses are required to change the molecular weight (20-40 kGy), with moisture playing a protective role. Selected systems have been conjugated to doxorubicin (DOX), a powerful anticancer drug that is extensively applied in the clinical treatment of human malignancies, such as leukemia and cancer of the liver, ovary and breast. This drug causes severe peripheral toxicity that poses limits to the maximum dosage that can be administered, and the emergence of multidrug resistance. DOX has been bound to irradiated XG through a cleavable bond and then further loaded with DOX by self-assembly. Xyloglucan contains galactose, which can be recognised and internalised by asialoglycoprotein receptor (ASGP-R). In order to increase the targeting efficiency, XG has been also conjugated to folic acid. Drug release efficiency and tumour cells selectivity are under investigation
Fed-batch pre-industrial production and purification of a consensus tetratricopeptide repeat (CTPR) scaffold as a container for Fluorescent Proteins (FPs)
No full textWhite light-emitting diodes (WLEDs) are big news in the field of lighting, however, current production processes are still very expensive or based on unsustainable inorganic metals such as inorganic phosphorus.
The EU-funded ARTIBLED project aims to produce low-cost and high-efficiency Bio-hybrid light-emitting diodes (Bio-HLEDs). This can be achieved using artificially synthesized fluorescent proteins linked in biological scaffolds like the packaging to obtain LED for lighting applications containing a biogenic phosphor.
This study aims to optimize the protein scaffold CTPR10 production process to obtain a high number of scaffolds with a good purity level for Bio-HLEDs construction. Different fed-batch fermentation procedures were investigated and it was possible to produce more than two times of biomass and intracellular proteins compared to a conventional fed-batch strategy.
The improvement in production leads both to the reduction of costs related to the amount of IPTG used and the isolation of a consistent amount of CTPR10 through rapid and highly efficient purification techniques.
The realization of this project represents a significant milestone for Europe which will be at the forefront of innovation in the lighting sector
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
Effects of Cerebrospinal Fluids from Alzheimer and Non-Alzheimer Patients on Neurons–Astrocytes–Microglia Co-Culture
Full text linkAlzheimer’s disease (AD) is the most common form of dementia, characterized by the
accumulation of β-amyloid plaques, tau tangles, neuroinflammation, and synaptic/neuronal loss,
the latter being the strongest correlating factor with memory and cognitive impairment. Through
an in vitro study on a neurons–astrocytes–microglia (NAM) co-culture system, we analyzed the
effects of cerebrospinal fluid (CSF) samples from AD and non-AD patients (other neurodegenerative
pathologies). Treatment with CSF from AD patients showed a loss of neurofilaments and spheroids,
suggesting the presence of elements including CX3CL1 (soluble form), destabilizing the neurofilaments,
cellular adhesion processes, and intercellular contacts. The NAM co-cultures were analyzed
in immunofluorescence assays for several markers related to AD, such as through zymography,
where the expression of proteolytic enzymes was quantified both in cell extracts and the co-cultures’
conditioned medium (CM). Through qRT-PCR assays, several genes involved in the formation of
β-amyloid plaque, in phosphorylation of tau, and in inflammation pathways and MMP expression
were investigated
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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