1,721,056 research outputs found
INHALATION DRUG DELIVERY Techniques and Products
No full textProvides students and those in industry with concise clear guide to the essential fundamentals in inhalation drug deliver
PREPARATION OF SOLVENT-FREE LIPID MICROPARTICLES AS SUSTAINED RELEASE SYSTEM FOR INHALATION
No full textA solid-lipid microparticle system containing budesonide was prepared. The solid-lipid system was studied in terms of morphology, particle-size distribution, crystallinity, thermal properties, aerosol performance and dissolution/diffusion release. In addition, the microparticle system was compared to conventional spray-dried crystalline and amorphous budesonide samples. The particle size distributions of the crystalline, amorphous and solid-lipid microparticles, measured by laser diffraction, were similar; however, the microparticle morphology was more irregular than the spray dried drug samples. The thermal response of the solid-lipid microparticles suggested polymorphic transition and melting of the lipid, glycerol behenate (at ~48°C and ~72°C). No budesonide melting or crystallisation peaks were observed (as was seen in the drug only samples) suggesting that the budesonide was integrated into the matrix. X-ray powder diffraction patterns of the crystalline and amorphous budesonide were consistent with previous studies while the solid-lipid microparticles showed two peaks, at approximately 21.3 and 23.5 2θ suggesting the metastable sub-α and primarily β’ form. Analysis of the in vitro diffusion/dissolution of the formulations was studied using a flow through model and the curves analysed using difference/similarity factors and fitted using the Higuchi model. Regression analysis of this data set indicated differences in the t0.5, where values of 49.7, 35.3 and 136.9 mins were observed for crystalline, amorphous and the solid-lipid microparticles, respectively. The aerosol performance (<5μm), measured by multistage-liquid-impinger, was 29.5% and 27.3%, 21.1% ± 0.6% for the crystalline, amorphous and the solid-lipid microparticles, respectively. This study has shown solid-lipid microparticles may provide a useful approach to controlled release respiratory therapy
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
Incorporation of quercetin in respirable lipid microparticles: Effect on stability and cellular uptake on A549 pulmonary alveolar epithelial cells
No full textThe aim of the present study was to develop controlled release inhalable lipid microparticles (LMs) loaded with the antioxidant flavonoid, quercetin and to investigate the interaction of these microparticles with A549 pulmonary alveolar epithelial cells. The LMs were produced using different lipidic materials and surfactants, by melt emulsification followed by a sonication step. The most efficient modulation of the in vitro release of quercetin was achieved by the LMs prepared with tristearin and hydrogenated phosphatidylcholine, which were used for subsequent studies.These LMs exhibited a quercetin loading of 11.8. ±. 0.3%, and a volume median diameter, determined by laser diffraction, of 4.1. ±. 0.2. μm. Moreover, their mass median aerodynamic diameter (4.82. ±. 0.15. μm) and fine particle fraction (27.2. ±. 3.9%), as measured by multi-stage liquid impinger, were suitable for pulmonary delivery. Quercetin was found to be highly unstable (complete decomposition within 6-h incubation) in Ham's F-12 medium used for A549 cell culture. Degradation was markedly reduced (16.4% of the initial quercetin content still present after 24-h incubation) after encapsulation in the lipid particle system.Viability studies performed by lactate dehydrogenase assay, demonstrated that quercetin LMs showed no significant cytotoxicity on the A549 cells, over the concentration 0.1-5. μM. The uptake of quercetin by the A549 lung alveolar cells was also investigated. After 4-h incubation, the accumulation of quercetin in the A549 cells was significantly higher (2.3-fold increase) for the microparticle entrapped flavonoid when compare to non-encapsulated quercetin. The enhanced intracellular delivery of quercetin achieved by the LMs is likely due to the flavonoid stabilization after encapsulation. © 2013 Elsevier B.V
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
Personalised Aerosol Loading and Management (PALM):a handheld device for aerosol drug delivery
Full text linkIn this article, Jason Brenker, PhD, Research Fellow, and Tuncay Alan, PhD, Senior Lecturer, both of Monash University, and Daniela Traini, PhD, Professor, Macquarie Medical School and the Woolcock Institute of Medical Research, introduce the PALM – Personalised Aerosol Loading and Management – device, a unique, advanced drug delivery device enabling personalised delivery of aerosols to improve the efficacy of inhaled medications and patient compliance.</p
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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