1,722,185 research outputs found
Total intravenous anesthesia and target-controlled infusion
No full textTotal intravenous anesthesia (TIVA) is the use of intravenous agents for induction and maintenance of anesthesia. The
most frequently used agent is propofol. Propofol effect is usually
augmented with an opioid (e.g., remifentanil). Although it is possible to implement TIVA using pumps with the infusion rate
controlled manually, the advent of pumps programmed with
pharmacokinetic information has facilitated use. The use of published pharmacokinetic parameter sets (referred to as models and
often described by the principal author) allows the pump to determine infusion rates to maintain a certain plasma concentration
(Cp) and the addition of an effect-site equilibration constant
(keo) allows effect-site drug concentration prediction. Covariate
knowledge (e.g., weight, age) allows individualization of dose.
Recommended target concentrations for both propofol and remifentanil depend on the type of surgery, the degree of surgical
stimulation, the use of local anesthetic blocks and the ventilation
status of the patient. The use of processed EEG monitoring is
helpful in pediatric TIVA anesthesia, particularly in the presence
of neuromuscular blockade
Volume, Growth, and Stand Dynamics of a 192-year Old Pinus resinosa (Red Pine) Forest
No full textRussell, Matthew B.; Anderson, Brian. (2016). Volume, Growth, and Stand Dynamics of a 192-year Old Pinus resinosa (Red Pine) Forest. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/216441
Pharmacology of Drugs used in Children
No full textThe pharmacokinetics (PK) and pharmacodynamics
(PD) of most medications in children, especially neonates, differ
from those in adults. Children have immature renal and hepatic
functions, different body composition, altered protein binding,
distinct disease spectrum, diverse behavior, and dissimilar receptor
patterns. PK differences necessitate that the dose is modified to
achieve the desired concentration to elicit an appropriate pharmacodynamic response and to avoid toxicity. Some medications may
displace bilirubin from its protein binding sites, predisposing to
kernicterus in premature neonates. Drug effect may be influenced
by the reduced capacity of end organs such as the heart, neuromuscular junction, and brain to respond to medications in children compared with adults. In this chapter we discuss basic
pharmacologic principles as they relate to drugs commonly used
in infants and children
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
Modeling and analyzing competitive epidemic diseases with partial and waning virus-specific and cross-immunity
Full text linkIn this paper, we consider a novel mathematical modeling framework for the spread of two competitive diseases in a well-mixed population. The proposed framework, which we term a bivirus SIRIS model, encapsulates key real-world features of natural immunity, accounting for different levels of (partial and waning) virus-specific and cross protection acquired after recovery. Formally, the proposed framework consists of a system of coupled nonlinear ordinary differential equations that builds on a classical bivirus susceptible-infected-susceptible model by means of the addition of further states to account for (temporarily) protected individuals. Through the analysis of the proposed framework and of two specializations, we offer analytical insight into how natural immunity can shape a wide range of complex emergent behaviors, including eradication of both diseases, survival of the fittest one, or even steady-state co-existence of the two diseases
On a bi-virus epidemic model with partial and waning immunity
Full text linkWe propose a deterministic compartmental model to study the impact of partial and waning immunity on the spread of two competitive epidemic diseases, hereafter termed viruses. Building on a standard bi-virus SIS model, we introduce additional compartments to account for individuals who recovered from each virus, and tunable parameters to capture the level of virus-specific and cross protection acquired after recovery from a specific virus, and the rate at which such immunity could wane. We formalise the model as a system of nonlinear ordinary differential equations, which is amenable to analytical treatment, and we focus our analysis on two specialisations of the model. First, in the absence of waning immunity, we establish a global convergence result showing that, above the epidemic threshold, only the “fittest” virus becomes endemic. Second, in the absence of cross-immunity, we demonstrate instead that long-lasting co-existence of the two viruses may emerge, depending on the model parameters
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