1,043 research outputs found
The Global Exportation of the U.S. Bayh-Dole Act
Special issue: Intellectual Property and Technolog
Modeling the drug release from hydrogel-based matrices
In this work the behavior of hydrogel-based matrices, the most widespread systems for oral controlled release of pharmaceuticals, has been mathematically described. In addition, the calculations of the model have been validated against a rich set of experimental data obtained working with tablets made of hydroxypropyl methylcellulose (a hydrogel) and theophylline (a model drug). The model takes into account water uptake, hydrogel swelling, drug release, and polymer erosion. The model was obtained as an improvement of a previous code, describing the diffusion in concentrated systems, and obtaining the erosion front (which is a moving boundary) from the polymer mass balance (in this way, the number of fitting parameters was also reduced by one). The proposed model was found able to describe all the observed phenomena, and then it can be considered a tool with predictive capabilities, useful in design and testing of new dosage systems based on hydrogels
Machine learning using host/guest energy histograms to predict adsorption in metal–organic frameworks: Application to short alkanes and Xe/Kr mixtures
A machine learning (ML) methodology that uses a histogram of interaction energies has been applied to predict gas adsorption in metal–organic frameworks (MOFs) using results from atomistic grand canonical Monte Carlo (GCMC) simulations as training and test data. In this work, the method is first extended to binary mixtures of spherical species, in particular, Xe and Kr. In addition, it is shown that single-component adsorption of ethane and propane can be predicted in good agreement with GCMC simulation using a histogram of the adsorption energies felt by a methyl probe in conjunction with the random forest ML method. The results for propane can be improved by including a small number of MOF textural properties as descriptors. We also discuss the most significant features, which provides physical insight into the most beneficial adsorption energy sites for a given application
Protocol for a Multicenter Study
Background: In Parkinson’s disease (PD), alpha-synuclein accumulation in
cutaneous autonomic pilomotor and sudomotor nerve fibers has been linked to
autonomic nervous system disturbances even in the early stages of the disease.
This study aims to assess the association between alpha-synuclein-mediated
structural autonomic nerve fiber damage and function in PD, elucidate the role
of neuropathy progression during the early disease stages, and test
reproducibility and external validity of pilomotor function assessment using
quantitative pilomotor axon-reflex test and sudomotor function via
quantitative direct and indirect test of sudomotor function. Methods/design: A
prospective controlled study will be conducted at four study sites in Europe
and the USA. Fifty-two male and female patients with idiopathic PD (Hoehn and
Yahr 1–2) and 52 age- and sex-matched healthy controls will be recruited.
Axon-reflex-mediated pilomotor erection will be induced by iontophoresis of
phenylephrine on the dorsal forearm. Silicone impressions of the response will
be obtained, scanned, and quantified for pilomotor muscle impressions by
number, impression size, and area of axon-reflex spread. Axon-reflex-mediated
sweating following acetylcholine iontophoresis will be quantified for number
and size of droplets and axon-reflex spread. Sympathetic skin responses,
autonomic and motor symptoms will be evaluated. Tests will be performed at
baseline, after 2 weeks, 1, 2, and 3 years. Skin biopsies will be obtained at
baseline and after 3 years and will be analyzed for nerve fiber density and
alpha-synuclein accumulation. Discussion: We anticipate that progression of
autonomic nerve dysfunction assessed via pilomotor and sudomotor axon-reflex
tests is related to progression of autonomic symptom severity and alpha-
synuclein deposition. Potential applications of the techniques include
interventional studies evaluating disease-modifying approaches and clinical
assessment of autonomic dysfunction in patients with PD. Clinical trail
registration: TRN NCT03043768
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