1,721,085 research outputs found
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
New formulation and delivery method of Cryphonectria parasitica for biological control of chestnut blight
Full text linkAims:
This study aimed to develop a new formulation of Cryphonectria parasitica hypovirulent mycelium suitable for inoculations of tall trees from the ground. C. parasitica hypovirulent strains are widely used for biological control of chestnut blight. However, it is often inconsistent and ineffective not only for biological reasons, but also because the current manual application of hypovirulent strains on adult plants is difficult, time-consuming and expensive. Here, we propose an improved formulation and more effective mode of application of hypovirulent strains, which could boost chestnut blight biocontrol.
Methods and results:
The Cp 4.2H hypovirulent strain was formulated as mycelium disks with polyethylene glycol (PEG) and hydroxypropyl methylcellulose (HPMC), loaded into lead-free pellets used as carriers to inoculate cankers on chestnut stems by shooting. The formulation of the mycelium did not hamper its viability which was stable, with an estimated shelf life of 72 days at 6±1 °C. The inoculum effectiveness was confirmed ex planta and in planta in a small-scale pilot study in field, where formulated mycelium disks of hypovirulent strain Cp 4.2H were airgun shot into the chestnut bark. In planta, Cp 4.2H was recovered in 37% of bark samples taken around the inoculated points one year after the treatment.
Conclusions:
We demonstrated that the proposed airgun shooting inoculation method of C. parasitica hypovirulent strain formulated as mycelium disks is suitable for treatment of adult chestnut trees.
Significance and impact of the study:
The proposed method could be a valid alternative to the traditional manual technique of chestnut biocontrol. The main advantages are the cost-effectiveness and the ease to treat high-positioned, otherwise unreachable cankers both in orchards and forests. This article is protected by copyright. All rights reserved
A novel powder coating process for attaining taste masking and moisture protective films applied to tablets
No full textA novel powder coating process was developed for the application of taste masking and moisture protective films on tablets while avoiding the use of solvents or water. The coalescence of particles to form a polymeric film was investigated through studies of dry powder layering of micronized acrylic polymer (E PO) to produce free films. Theophylline containing tablets were coated with the same acrylic polymer in a laboratory scale spheronizer using a powder coating technique. The dry powder layer delayed the onset of drug release in pH 6.8 medium, depending on the coating level, while no delay was observed in pH 1.0 medium. The presence of hydrophilic polymers in the acrylic coating layer decreased the lag time for drug release in pH 6.8 medium, while only the presence of HPMC in the film slowed the drug release rate in acidic medium. The dry coating process was demonstrated to be a reliable alternative to solvent or aqueous film coating technologies for applying taste masking and moisture protective film coats onto compressed tablets. A controlled drug release profile was achieved in pH 6.8 media
Piattaforme di rilascio orali in forma di contenitori funzionali realizzate mediante injection molding
No full textI sistemi di rilascio somministrati oralmente si avvalgono di strategie formulative/tecnologiche per aumentare la biodisponibilità o modificare la cessione del principio attivo in termini di velocità, tempo o sito. Una delle configurazioni in cui più spesso si presentano è costituita da un nucleo contenente il farmaco rivestito con materiali polimerici dotati di specifiche proprietà che ne caratterizzano il comportamento e/o ne definiscono l’applicazione (es. sistemi gastroresistenti, reservoir). In una prospettiva di industrializzazione, sarebbe particolarmente vantaggioso poter svincolare lo sviluppo formulativo dell’elemento di controllo del rilascio, ovvero la barriera polimerica esterna, da quello del core contenente l’attivo. In quest’ottica appare molto promettente la tecnica di injection molding (IM) che prevede l’iniezione di materiale opportunamente rammollito (movimentazione e riscaldamento) in uno stampo che gli conferisce una forma tridimensionale definita. Sulla base delle proprietà funzionali (solubilità pH-dipendente, capacità di rigonfiamento e dissoluzione/erosione, permeabilità) sono stati selezionati una serie di materiali polimerici di comune impiego farmaceutico (HPMCAS, HPC, EC) con i quali valutare la fattibilità di realizzazione di una gamma di piattaforme di rilascio. Si tratta di contenitori in forma capsulare, ovvero di sistemi adatti ad essere riempiti con varie tipologie di formulazioni, capaci di determinare la performance di rilascio dell’attivo veicolato sulla base, esclusivamente, delle caratteristiche di composizione (natura del polimero) e spessore delle pareti. In particolare, vengono presentati risultati relativi alla lavorabilità dei materiali e alle caratteristiche tecnologiche e di performance di capsule gastroresistenti e a rilascio ritardato o prolungato
Dry powder coating of pharmaceuticals: A review
No full textOver the last half century, film coating technology has evolved significantly in terms of compositions and manufacturing processes, allowing for greater functionality, flexibility and efficiency. Driven by a combination of cost considerations and functionality, a range of dry powder coating technologies have been developed in both academic and industrial settings. These technologies can be generally classified into three major types based on the layer formation process: liquid assisted, thermal adhesion and electrostatic. In addition to specific manufacturing processes that must be implemented to achieve the desired product attributes, many of these techniques also require the use of novel excipients and specific formulations to provide acceptable manufacturability. This review summarizes the current dry powder coating technologies and highlights their industrial applicability with publicly disclosed case studies. Commentary on the future directions of dry powder coating is also provided
What is the future potential of microbially degradable systems in drug delivery to the colon?
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