The effect of buzzy®, DistrACTION® cards on reducing pediatric pain and fear during blood collection in the rheumatology polyclinic: A randomized controlled trial.

PURPOSE: The aim of this study was to compare the effectiveness of Buzzy® and DistrACTION® Cards in reducing children's pain and fear while taking venous blood samples. METHODS: This research was designed as a randomized controlled experimental study. The study population consisted of children aged 6-12 years admitted to the Pediatric Rheumatology Diseases Polyclinic in a Faculty of Medicine in Germany. The sample of the study consisted of 96 children (Buzzy® = 32, DistrACTION® Cards = 32, control = 32) who met the patient selection criteria and agreed to participate in the study. The data were obtained using a Child and Family Information Form, the Children Fear Scale (CFS), and the Faces Pain Scale-Revised (FPS-R). The data were evaluated using the Pearson chi-square test, Kruskal-Wallis test, One-way ANOVA test with Bonferroni correction, and Fisher-Freeman-Halton. FINDINGS: In the study, the average age of the children was 9.21 ± 2.15 years. The Buzzy® group had the lowest pain and procedural fear scores (self-report = 0.88 ± 1.13, 0.31 ± 0.47; parent report = 0.75 ± 0.98, 0.34 ± 0.48, and researcher report = 0.81 ± 1.00, 0.31 ± 0.54, respectively) than the DC, and control groups. CONCLUSIONS: The Buzzy® method was effective in reducing venipuncture pain and fear in children. PRACTICE IMPLICATIONS: Nurses can use the Buzzy® methods to help reduce venipuncture pain and fear in children. The clinical trial registration number is NCT05560074. (https://clinicaltrials.gov/ct2/show/study/NCT05560074).

A spatially-distributed computational model to quantify behaviour of contrast agents in MR perfusion imaging.

Contrast agent enhanced magnetic resonance (MR) perfusion imaging provides an early, non-invasive indication of defects in the coronary circulation. However, the large variation of contrast agent properties, physiological state and imaging protocols means that optimisation of image acquisition is difficult to achieve. This situation motivates the development of a computational framework that, in turn, enables the efficient mapping of this parameter space to provide valuable information for optimisation of perfusion imaging in the clinical context. For this purpose a single-compartment porous medium model of capillary blood flow is developed which is coupled with a scalar transport model, to characterise the behaviour of both blood-pool and freely-diffusive contrast agents characterised by their ability to diffuse through the capillary wall into the extra-cellular space. A parameter space study is performed on the nondimensionalised equations using a 2D model for both healthy and diseased myocardium, examining the sensitivity of system behaviour to Peclet number, Damköhler number (Da), diffusivity ratio and fluid porosity. Assuming a linear MR signal response model, sample concentration time series data are calculated, and the sensitivity of clinically-relevant properties of these signals to the model parameters is quantified. Both upslope and peak values display significant non-monotonic behaviour with regard to the Damköhler number, with these properties showing a high degree of sensitivity in the parameter range relevant to contrast agents currently in use. However, the results suggest that signal upslope is the more robust and discerning metric for perfusion quantification, in particular for correlating with perfusion defect size. Finally, the results were examined in the context of nonlinear signal response, flow quantification via Fermi deconvolution and perfusion reserve index, which demonstrated that there is no single best set of contrast agent parameters, instead the contrast agents should be tailored to the specific imaging protocol and post-processing method to be used.

A computationally efficient framework for the simulation of cardiac perfusion using a multi-compartment Darcy porous-media flow model.

We present a method to efficiently simulate coronary perfusion in subject-specific models of the heart within clinically relevant time frames. Perfusion is modelled as a Darcy porous-media flow, where the permeability tensor is derived from homogenization of an explicit anatomical representation of the vasculature. To account for the disparity in length scales present in the vascular network, in this study, this approach is further refined through the implementation of a multi-compartment medium where each compartment encapsulates the spatial scales in a certain range by using an effective permeability tensor. Neighbouring compartments then communicate through distributed sources and sinks, acting as volume fluxes. Although elegant from a modelling perspective, the full multi-compartment Darcy system is computationally expensive to solve. We therefore enhance computational efficiency of this model by reducing the N-compartment system of Darcy equations to N pressure equations, and N subsequent projection problems to recover the Darcy velocity. The resulting 'reduced' Darcy formulation leads to a dramatic reduction in algebraic-system size and is therefore computationally cheaper to solve than the full multi-compartment Darcy system. A comparison of the reduced and the full formulation in terms of solution time and memory usage clearly highlights the superior performance of the reduced formulation. Moreover, the implementation of flux and, specifically, impermeable boundary conditions on arbitrarily curved boundaries such as epicardium and endocardium is straightforward in contrast to the full Darcy formulation. Finally, to demonstrate the applicability of our methodology to a personalized model and its solvability in clinically relevant time frames, we simulate perfusion in a subject-specific model of the left ventricle.

A novel porous mechanical framework for modelling the interaction between coronary perfusion and myocardial mechanics.

The strong coupling between the flow in coronary vessels and the mechanical deformation of the myocardial tissue is a central feature of cardiac physiology and must therefore be accounted for by models of coronary perfusion. Currently available geometrically explicit vascular models fail to capture this interaction satisfactorily, are numerically intractable for whole organ simulations, and are difficult to parameterise in human contexts. To address these issues, in this study, a finite element formulation of an incompressible, poroelastic model of myocardial perfusion is presented. Using high-resolution ex vivo imaging data of the coronary tree, the permeability tensors of the porous medium were mapped onto a mesh of the corresponding left ventricular geometry. The resultant tensor field characterises not only the distinct perfusion regions that are observed in experimental data, but also the wide range of vascular length scales present in the coronary tree, through a multi-compartment porous model. Finite deformation mechanics are solved using a macroscopic constitutive law that defines the coupling between the fluid and solid phases of the porous medium. Results are presented for the perfusion of the left ventricle under passive inflation that show wall-stiffening associated with perfusion, and that show the significance of a non-hierarchical multi-compartment model within a particular perfusion territory.

Genetic structure inside a declining red oak community in old-growth forest.

Problems with oak regeneration have been documented in the last 50 years at numerous sites in the Midwestern United States. We applied nuclear microsatellites to examine the demographic and fine-scale spatial genetic structure of red oaks in two old-growth stands in Indiana. Oaks in one stand have declined in numbers over the past several decades whereas oaks in the other, smaller stand have increased. Large amounts of genetic variation were maintained within stands, and there was slight but significant differentiation among stands. There was significant but weak isolation by distance genetic structure within the large stand, likely reflecting family structure. No significant differences exist in allele frequencies or in levels of genetic diversity between cohorts that remain well represented within each stand, even between medium-sized adults and those antedating European settlement of the area. However, a virtual absence of smaller size classes in the forest interior of the large stand represents the early stages of a genetic bottleneck in what had been the core habitat of this stand. Whether future generations of this old-growth stand will retain the present genetic character depends on the oaks regenerating at the forest margins, absent any major changes in disturbance regimes. Similar demographic and genetic dynamics are likely occurring in a large number of remnant oak forests across the Midwest.

Thirty polymorphic nuclear microsatellite loci from black walnut.

Black walnut (Juglans nigra L) is a large tree, native to the eastern United States, that is prized for its high-quality timber and edible nut. Thirty (GA/CT)n nuclear microsatellite markers were identified from black walnut for use in population genetic studies, genome mapping, DNA genotyping of important clones, studies of gene flow, and tree breeding. The markers were polymorphic based on a diversity panel of 10 black walnut individuals from eight Midwestern U.S. states.

[Late results following implantation of aortic bifurcation prosthesis]. / Spätergebnisse nach Implantation von Aortenbifurkationsprothesen.

From January 1976 to December 1986 181 patients with chronic arterial occlusive disease were provided with an Y-prosthesis of the aorta. In a retrospective study we reviewed the history of these patients. From 130 (72%) patients we obtained information about the further course of the disease, 83 (46%) patients were reexamined. Depending on the preoperative stage (Fontaine-Ratschow classification) of the chronic arterial occlusive disease, patients in higher stages had a greater benefit from the implantation by shifting into a more satisfactory stage. The majority of patients without any postoperative complaints (48%) belonged to the group, preoperatively classified into stage II B. Depending on the type of occlusion the best results were obtained in unique occlusions of the aorto-iliac vascular segment. 50% of the reexamined patients had no complaints although in 61% of these cases the superficial femoral artery was occluded in the mean time. 47 patients deceased during the interval of observation. In most cases death was caused by other manifestations of the basic disease (e.g. cardiac infarction or cerebral apoplexy). The 10-year-survival rate was 59%. The majority of patients with chronic occlusive disease of the pelvic arteries profited from the implantation of an aortal Y-prosthesis. The long-term success of this operation with its low lethality depends on the preoperative stage and the extent of the occlusive process.

A highly sensitive method for quantitative determination of abscisic Acid.

An abscisic acid derivative was formed by reaction with pentafluorobenzyl bromide which allowed highly sensitive detection by gas-liquid chromatography with electron capture detection. In comparison to the methyl ester derivative, the pentafluorobenzyl derivative of abscisic acid was four times more sensitive to electron capture detection and was stable at room temperature in the presence of ultraviolet light. Derivatization was rapid and the molecular weight of the new compound was confirmed by gas-liquid chromatography-mass spectrometry.