287 research outputs found
Digital badges for STEM learning in secondary contexts: A mixed methods study
The deficit in STEM skills is a matter of concern for national economies and a major focus for educational policy makers. The development of Information and Communications Technologies (ICT) has resulted in a rapidly changing workforce of global scale. In addition, ICT have fostered the growth of digital and mobile technologies which have been the learning context, formal and informal, for a generation of youth. The purpose of this study was to design an intervention based upon a competency-based, digitally-mediated, learning intervention: digital badges for learning STEM habits of mind and practices. Designed purposefully, digital badge learning trajectories and criteria can be flexible tools for scaffolding, measuring, and communicating the acquisition of knowledge, skills, or competencies. One of the most often discussed attributes of digital badges, is the ability of badges to motivate learners. However, the research base to support this claim is in its infancy; there is little empirical evidence. A skills-based digital badge intervention was designed to demonstrate mastery learning in key, age-appropriate, STEM competencies aligned with Next Generation Science Standards (NGSS) and other educational standards. A mixed methods approach was used to study the impact of a digital badge intervention in the sample middle and high school population. Among the findings were statistically significant measures which substantiate that in this student population, the digital badges increased perceived competence and motivated learners to persist at task
Influences of copolymers (Copovidone, Eudragit RL PO and Kollicoat MAE 30 DP) on stability and bioactivity of spray-dried and freeze-dried lysozyme
Insights into the influences of carboxymethyl-β-cyclodextrin on DNA formulations characteristics and gene transfection efficiency
BACKGROUND
Gene therapy is an expanding field and it can treat genetic and acquired diseases.
OBJECTIVE
It was found that formulations with DNA: CM-β-CD (Carboxymethyl-beta-cyclodextrin): Pluronic-F127 1:3:3 and 1:3 DNA: CM-β-CD are the most stable formulations indicating high incorporation of DNA within CM-β -CD.
METHOD
Gel electrophoresis revealed DNA with low CM-β -CD concentration has formed a more stable complex. Samples 1:3 DNA: CM-β-CD and 1:3:3 DNA: CM-β-CD: Pluronic-127 show no DNA fragment, suggesting good condensation of DNA inside cyclodextrin cavity.
RESULTS
This was confirmed by fluorescence data where fluorescence intensity was reduced for samples DNA: CM-β-CD 1:3. Overall, the findings showed that Carboxymethyl-beta-cyclodextrin (as a novel non-viral gene vector) was able to provide condensation and protection to the DNA, with and without Pluronic-F127, at low concentration.
CONCLUSION
pDNA/CM-β-CD complex has not only shown to be able to transfect COS 7 and SHSY5Y cell lines, but it gives a higher transfection efficiency than that produced by the TransIT-LT1 commercial transfection reagent
Effect of Spray-Drying and Electrospraying as Drying Techniques on Lysozyme Characterisation
The production of biopharmaceutical formulation incorporates several difficulties embracing their physical and chemical instabilities. In this study, two drying techniques, namely, spray-drying and electrospraying, were used to assess their application on lysozyme (as a model protein) without and with the use of betacyclodextrin. Samples were prepared in the ratio of 1:1 w/w (protein/betacyclodextrin), and several characterisation methods were applied to study the percentage (%) yield, morphology of the produced partials, thermal stability and biological activity of the protein. The results show the two drying methods led to different particle morphology as spherical-like shape was produced by spray-drying, while rodlike shape was generated by electrospraying with larger particle size. Lysozyme formulations produced by electrospraying were stable just directly after preparation, but after few weeks, those formulations showed visible aggregates. The biological activity of lysozyme was preserved by both drying techniques. In conclusion, both drying methods have different effects on the protein integrity and biological activity in which spray-drying shows more promising results
Wet granulation to overcome liquisolid technique issues of poor flowability and compactibility: A study to enhance Glibenclamide dissolution
The aim of this study is to apply wet granulation on liquisolid powders to overcome issues of poor powder flowability and compressibility especially with using high viscosity liquid vehicles. Different liquisolid formulations were made using three excipients where the effect of each excipient used in the dissolution of the model hydrophobic drug (Glibenclamide) was evaluated. The Glibenclamide tablets were formulated using PEG 400, Synperonic PE/L44 and Cremophor ELP, at a 10 %w/w in liquid vehicle drug concentration. The carrier (Avicel®PH102) was used followed by colloidal silicon dioxide (coating material) that converted the wet mixture into dry powder. Potato starch, 5%w/w, as a disintegrant was mixed with the mixture manually for 10 minutes and was finalized by adding 0.75% of magnesium stearate as a lubricant. The final powder (depending on its flowability and compactability) was then compacted automatically using a single-punch tableting machine to give tablets with 4mg unit drug dose. Prepared liquisolid compacts were characterised via B.P. quality control tests. In this study, a novel discovery was achieved to overcome the major problems with liquisolid preparations (flowability and compactability). This new technique is the wet granulation process to be applied with liquisolid powders just before the compaction stage of the powders into tablets. Consequently, it was found that by application of wet granulation to liquisolid powder admixture, the large-scale production of liquisolid compacts is feasible and can be easily applied by pharmaceutical industry. As with some liquisolid vehicles especially high viscosity although very good to enhance dissolution usually formulations are studied in powder forms [1,2]
The Development of ‘Meaning’ in Literary Theory: A Comparative Critical Study
This research project studies different approaches to the question of meaning in literary texts in medieval Islamic critical traditions and modern Western literary criticism. Based on a comparative analysis, the dissertation attempts to explain each theory in its own terms, to find the commonalities and differences of the handling of such a question by literary theories, to establish a dialogue between the theories to understand them better and in wider terms. Thus, the dissertation also analyzes some texts by looking at them through the lenses of different theories
Design and evaluation of effervescent floating tablets based on hydroxyethyl cellulose and sodium alginate using pentoxifylline as a model drug
The aim of this work was to design and evaluate effervescent floating gastro-retentive
drug delivery matrix tablets with sustained-release behavior using a binary mixture of
hydroxyethyl cellulose and sodium alginate. Pentoxifylline was used as a highly water-soluble,
short half-life model drug with a high density. The floating capacity, swelling, and drug release
behaviors of drug-loaded matrix tablets were evaluated in 0.1 N HCl (pH 1.2) at 37°C±0.5°C.
Release data were analyzed by fitting the power law model of Korsmeyer–Peppas. The effect
of different formulation variables was investigated, such as wet granulation, sodium bicarbonate
gas-forming agent level, and tablet hardness properties. Statistical analysis was applied
by paired sample t-test and one-way analysis of variance depending on the type of data to
determine significant effect of different parameters. All prepared tablets through wet granulation
showed acceptable physicochemical properties and their drug release profiles followed
non-Fickian diffusion. They could float on the surface of dissolution medium and sustain drug
release over 24 hours. Tablets prepared with 20% w/w sodium bicarbonate at 50–54 N hardness
were promising with respect to their floating lag time, floating duration, swelling ability, and
sustained drug release profile.
Keywords: floating tablets, sodium alginate, pentoxifylline, dissolution, swelling,
effervescen
Naproxen Microparticulate Systems Prepared Using In Situ Crystallisation and Freeze-Drying Techniques
Solaiman, A., Tatari, A.K. & Elkordy, A.A
Applications of spray drying and spray congealing to improve poorly water soluble drug dissolution
An overview for the effects of lactitol, gelucire 44/14 and copovidone on lysozyme biological activity
Lysozyme, a model protein, was used to study the effects of excipients (lactitol, copovidone and gelucire 44/14) on the protein biological activity. Three different concentrations (0.1, 0.5 and 10 %w/v) of the excipients were used with a relatively high (10%w/v) lysozyme concentration. Analytical methods such as UV spectroscopy and fluorescence technique were used to study the effect of excipients on protein biological stability and integrity. The data obtained from analysis showed that gelucire 44/14 had a disadvantage effect on lysozyme stability as a single excipient. However, by combining gelucire 44/14 with lactitol, the protein activity was preserved. Also, the combination of lactitol and copovidone preserved the integrity and activity of 6% lysozyme to a great extent. Different excipients stabilised proteins to different degree. As conclusion, there is no excipient that works well for even one type of proteins. The most suitable excipient for each particular protein is found by extensive research studying the activity and stability of the protein in the presence of excipients. High efficacy and accuracy analytic methods should be used in order to give reliable information on protein stability and integrity.
Keywords: lysozyme, lactitol, copovidone, gelucire 44/14, stability, biological activity
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