Search results for "INTERACTION"
showing 10 items of 5710 documents
Structural characterisation of the natural membrane-bound state of melittin: a fluorescence study of a dansylated analogue
1997
Abstract The binding of a dansylated analogue of melittin (DNC–melittin) to natural membranes is described. The cytolytic peptide from honey bee venom melittin was enzymatically labelled in its glutamine-25 with the fluorescent probe monodansylcadaverine using guinea pig liver transglutaminase. The labelled peptide was characterised functionally in cytolytic assays, and spectroscopically by circular dichroism and fluorescence. The behaviour of DNC–melittin was, in all respects, indistinguishable from that of the naturally occurring peptide. We used resonance energy transfer to measure the state of aggregation of melittin on the membrane plane in synthetic and natural lipid bilayers. When bo…
Transcriptome and metabolome analysis of citrus fruit to elucidate puffing disorder.
2014
a b s t r a c t A systems-level analysis reveals details of molecular mechanisms underlying puffing disorder in Citrus fruit. Flavedo, albedo and juice sac tissues of normal fruits and fruits displaying symptoms of puffing disorder were studied using metabolomics at three developmental stages. Microarrays were used to compare normal and puffed fruits for each of the three tissues. A protein-protein interaction network inferred from previous work on Arabidopsis identified hub proteins whose transcripts show significant changes in expression. Glycolysis, the backbone of primary metabolism, appeared to be severely affected by the disorder, based on both transcriptomic and metabolomic results. …
Supporting Dispute Handling in E-Commerce Transactions, a Framework and Related Methodologies
2004
An E-commerce transaction is a means to conduct particular commercial activities using the global digital E-commerce infrastructure. We concentrate here on business to customer (B-to-C) E-commerce transactions. These transactions are based on protocols offered by the global infrastructure, primarily the Internet. Using electronic means to do business can greatly improve the efficiency of the business transactions. It, however, poses some problems that were rarely considered to be important before. One class of problems is caused by the behavior of untrusted participants. For reasons such as dishonesty, disputes may arise. In the general case, when a dispute arises an untrustworthy participa…
Video-based Word Problems or Modelling Projects—Classifying ICT-based Modelling Tasks
2021
Mathematical modelling tasks increasingly feature the use of digital tools and media. In this chapter, we discuss the wide variety of these. Until now, classifications for modelling tasks did not consider the use of tools and media. Therefore, we developed a new classification for ICT-based modelling tasks. One class relates to mathematics; the others differentiate across (1) modelling aspects unrelated to tool and media, (2) the task context, (3) the digital tools and media (CAS, Wikipedia, type of feedback, etc.) and (4) students’ anticipated activities guided by task regulations, such as group work or time restrictions. The classification was validated with three example tasks. A visual …
Fitbit for learning: Towards capturing the learning experience using wearable sensing
2020
The assessment of learning during class activities mostly relies on standardized questionnaires to evaluate the efficacy of the learning design elements. However, standardized questionnaires pose additional strain on students, do not provide “temporal” information during the learning experience, require considerable effort and language competence, and sometimes are not appropriate. To overcome these challenges, we propose using wearable devices, which allow for continuous and unobtrusive monitoring of physiological parameters during learning. In this paper we set out to quantify how well we can infer students’ learning experience from wrist-worn devices capturing physiological data. We coll…
A Map-Based Visualization Tool To Support Tutors In E-Learning 2.0
2009
Web 2.0 regards essentially the social issues about the new usage of web applications, but participative web and user generated contents induce a new way to think about the design of the web applications themselves. This is particularly true in the field of educational systems that are all web based applications. Many researchers are now devoted to study what is called e-learning 2.0 both as regards the technological issues in the field of computer science, and in relation to the impact of the web 2.0 social and psychological issues on the education process itself. One of the most crucial topics in e-learning 2.0 is the way to provide support to the teacher/tutor to avoid cognitive overload…
Electrokinetic capillary chromatography in a polar continuous‐phase water‐in‐oil microemulsion constituted by water, sodium dodecyl sulfate, and n ‐p…
2005
A water-in-oil (w/o) microemulsion (ME) constituted by 15% Tris buffer, pH 8.4, in water and 85% sodium dodecyl sulfate (SDS)/n-pentanol 1:4 mixture, capable of dissolving up to 30% vegetable oils and lard, was used as background electrolyte in reverse microemulsion electrokinetic capillary chromatography (RMEEKC). Owing to the free SDS ions in the continuous phase and some degree of percolation, the ME showed a high conductivity (0.65 mS. cm(-1) at 25 degrees C) and sustained a very stable capillary current. Previous rinsing of the capillary with a quaternary ammonium salt for electroosmotic flow (EOF) reduction, a series of nonionic and anionic solutes dissolved either in the ME or in fat…
Efficiency of antidepressant drugs as monoamine reuptake inhibitors: analysis of the hydrophobicity influence using biopartitioning micellar chromato…
2004
The reuptake blockade of biogenic amines by antidepressants is related not only to their therapeutics effects, but also to their side effects and potential drug-drug interactions. As an alternative to classical quantitative structure-activity relationships studies, in this work we propose different quantitative retention-activity relationships (QRAR) models that are able to describe the monoamine reuptake inhibition by antidepressants. The retention of compounds is measured using a biopartitioning micellar chromatography (BMC) system that can simulate the same hydrophobic, electronic and steric molecular interactions as those that condition drug activity. Since all the compounds considered …
Results of Numerical Modeling of Blood Flow in the Internal Jugular Vein Exhibiting Different Types of Strictures
2022
The clinical relevance of nozzle-like strictures in upper parts of the internal jugular veins remains unclear. This study was aimed at understanding flow disturbances caused by such stenoses. Computational fluid dynamics software, COMSOL Multiphysics, was used. Two-dimensional computational domain involved stenosis at the beginning of modeled veins, and a flexible valve downstream. The material of the venous valve was considered to be hyperelastic. In the vein models with symmetric 2-leaflets valve without upstream stenosis or with minor 30% stenosis, the flow was undisturbed. In the case of major 60% and 75% upstream stenosis, centerline velocity was positioned asymmetrically, and areas of…
Rilevanza clinica delle interazioni farmacologiche di tipo farmacocinetico [Clinical significance of pharmacokinetic interactions]
2008
The correct realization of a pharmacological therapy needs the individuation of the most appropriate drugs for the treatment of the patient's disease. However, even the most effective, and potent and appropriate drugs cannot assure the therapeutic success, if that compound does not reach the site of action. This result can be obtained only if the physician knows the factors that regulate thepharmacokinetic parameters of the used drugs, i.e. absorption, distribution, metabolism, excretion, that regulate the onset velocity, the duration and the intensity of the drug effects. In the lost years, pharmacological interactions, i.e. the possibility that co-administered drugs interfere with each ot…