32 research outputs found
Calculation of the stability of composite rods according to the non-classical bending model
The problem of the effect of deformations of transverse shear and transverse
compression on the value of the critical stress in the problem of the loss of stability of a
transversely isotropic rod is considered. The fourth-order differential equation of the nonclassical bending model of rods is applied. Formulas for the critical stress are obtained, as well
as numerical results for rods made of different material
Coupling computer-interpretable guidelines with a drug-database through a web-based system – The PRESGUID project
BACKGROUND: Clinical Practice Guidelines (CPGs) available today are not extensively used due to lack of proper integration into clinical settings, knowledge-related information resources, and lack of decision support at the point of care in a particular clinical context. OBJECTIVE: The PRESGUID project (PREScription and GUIDelines) aims to improve the assistance provided by guidelines. The project proposes an online service enabling physicians to consult computerized CPGs linked to drug databases for easier integration into the healthcare process. METHODS: Computable CPGs are structured as decision trees and coded in XML format. Recommendations related to drug classes are tagged with ATC codes. We use a mapping module to enhance computerized guidelines coupling with a drug database, which contains detailed information about each usable specific medication. In this way, therapeutic recommendations are backed up with current and up-to-date information from the database. RESULTS: Two authoritative CPGs, originally diffused as static textual documents, have been implemented to validate the computerization process and to illustrate the usefulness of the resulting automated CPGs and their coupling with a drug database. We discuss the advantages of this approach for practitioners and the implications for both guideline developers and drug database providers. Other CPGs will be implemented and evaluated in real conditions by clinicians working in different health institutions
Uptake, Whole-Body Distribution, and Depuration of Nanoplastics by the Scallop Pecten maximus at Environmentally Realistic Concentrations
Previous studies of uptake and effects
of nanoplastics by marine
organisms have been conducted at what may be unrealistically high
concentrations. This is a consequence of the analytical challenges
in tracking plastic particles in organisms at environmentally relevant
concentrations and highlights the need for new approaches. Here, we
present pulse exposures of 14C-radiolabeled nanopolystyrene
to a commercially important mollusk, Pecten maximus, at what have been predicted to be environmentally relevant concentrations
(–1). Uptake was rapid and was
greater for 24 nm than for 250 nm particles. After 6 h, autoradiography
showed accumulation of 250 nm nanoplastics in the intestine, while
24 nm particles were dispersed throughout the whole-body, possibly
indicating some translocation across epithelial membranes. However,
depuration was also relatively rapid for both sizes; 24 nm particles
were no longer detectable after 14 days, although some 250 nm particles
were still detectable after 48 days. Particle size thus apparently
influenced the biokinetics and suggests a need for chronic exposure
studies. Modeling extrapolations indicated that it could take 300
days of continued environmental exposure for uptake to reach equilibrium
in scallop body tissues although the concentrations would still below
2.7 mg g–1. Comparison with previous work in which
scallops were exposed to nonplastic (silver) nanomaterials of similar
size (20 nm), suggests that nanoparticle composition may also influence
the uptake tissue distributions somewhat