ABSTRACT
Due to the characteristics such as high capture, high recovery and precise control with fluid, the microfluidic chip has attracted much attention in the research field of circulating tumor cells (CTCs). The developed microfluidic system mainly included three types based on the captured principles such as biological affinity tag microfluidic chip, free label microfluidic chip and rely on biological affinity with the physical properties of integrated microfluidic chip.
ABSTRACT
Vena cava filter is a filter device designed to prevent pulmonary embolism caused by thrombus detached from lower limbs and pelvis. A new retrievable vena cava filter was designed in this study. To evaluate hemodynamic performance and thrombus capture efficiency after transplanting vena cava filter, numerical simulation of computational fluid dynamics was used to simulate hemodynamics and compare it with the commercialized Denali and Aegisy filters, and in vitro experimental test was performed to compare the thrombus capture effect. In this paper, the two-phase flow model of computational fluid dynamics software was used to analyze the outlet blood flow velocity, inlet-outlet pressure difference, wall shear stress on the wall of the filter, the area ratio of the high and low wall shear stress area and thrombus capture efficiency when the thrombus diameter was 5 mm, 10 mm, 15 mm and thrombus content was 10%, 20%, 30%, respectively. Meanwhile, the thrombus capture effects of the above three filters were also compared and evaluated by in vitro experimental data. The results showed that the Denali filter has minimal interference to blood flow after implantation, but has the worst capture effect on 5 mm small diameter thrombus; the Aegisy filter has the best effect on the trapping of thrombus with different diameters and concentrations, but the low wall shear stress area ratio is the largest; the new filter designed in this study has a good filtering and capture efficiency on small-diameter thrombus, and the area ratio of low wall shear stress which is prone to thrombosis is small. The low wall shear stress area of the Denali and Aegisy filters is relatively large, and the risk of thrombosis is high. Based on the above results, it is expected that the new vena cava filter designed in this paper can provide a reference for the design and clinical selection of new filters.
Subject(s)
Humans , Blood Flow Velocity , Hemodynamics , Software , Thrombosis , Therapeutics , Vena Cava Filters , Vena Cava, InferiorABSTRACT
Abstract The capture of wild animals can provide important information on community structure, population dynamics, home range size, activity patterns, habitat use, denning, social behavior and health status. The objective of this study was to describe the method of capture with details on baits, injuries, non-target captures, anesthesia and costs, to evaluate its success as part of a health evaluation program of ocelots in a Brazilian Atlantic Forest Reserve. From a total of 1,011 trap-night effort in 86 days, we had 68 capture events composed of ocelots (22%, n=15) and non-target species (78%, n = 53). We captured 10 individual ocelots in 15 capture events, corresponding to 5.7 days to capture one ocelot. Capture efficiency was 14.8 ocelots/1,000 trap-nights effort. We suggest capture methods should be selected and implemented based on the following criteria: (i) high capture efficiency; (ii) high selectivity; (iii) low injury rate; (iv) high immobilization suitability; and (v) low costs, in order to enable comparisons of studies from different research groups and from different study areas, allowing a deliberate choice of the best method.
Resumo A captura de animais selvagens é capaz de proporcionar informações importantes acerca da estrutura da comunidade, dinâmica populacional, tamanho das áreas de vida, uso dos hábitats, locais de toca, comportamento social e estado de saúde. Este estudo teve como objetivo descrever o método de captura enfatizando as iscas utilizadas, ferimentos, capturas de espécies não-alvo, anestesia e custos, para avaliar o sucesso de captura como parte de um programa de avaliação de saúde de jaguatiricas numa reserva de Mata Atlântica no Brasil. De um de esforço total de 1.011 armadilhas-noite em 86 dias, nós tivemos 68 eventos de captura compostos de jaguatiricas (22%, n= 15) e espécies não-alvo (78%, n= 53). Nós capturamos 10 indivíduos diferentes em 15 eventos de captura, correspondendo a 5,7 dias para capturar uma jaguatirica. A eficiência de captura foi de 14,8 jaguatiricas/1.000 armadilhas-noite. Nós sugerimos que os métodos de captura deveriam ser selecionados e implementados com base nos seguintes critérios: (i) alta eficiência de captura; (ii) alta seletividade; (iii) baixa taxa de ferimentos; (iv) alta adequação de imobilização; e (v) baixos custos, de forma a viabilizar comparações de estudos de diferentes grupos e diferentes áreas, permitindo a escolha do melhor método.