Artificial capillary system

Considering the spatial geometry of cerebral capillaries and capillary blood flow, a number of dynamic models of the blood-brain barrier have been developed, in which endothelial cells are cultured inside a permeable tube, the outer surface of which is coated with astrocytes. Supply of the cells with nutrients and artificial blood flow are maintained by using a peristaltic pump system [112, 113]. 

The sample size has a considerable effect on the separation characteristics of a certain system. Therefore, the sample diameter on the plate should be kept as small as possible (<3mm). Inefficient separations and artificial results are caused by too-large spots. The standard TLC technique for applying a sample onto the plate is to use micropipets or glass capillaries for single use. The volume is typically 5 pi. A certain drawback of this technique is the fact that the sample is withdrawn aseptically with a syringe from the vial and needs to be transferred for spotting. 

If the above requirements are met, then the placenta is placed in the artificial uterus and perfusion by heparinized buffered solution (Appendix IA) is started as soon as possible to prevent clotting of the blood already present in the small capillaries. After the placenta is cleaned by perfusing with saline and the intactness of the placental membrane has been established, the blood perfusion is started. When the system has reached steady state (with regard to pressures, temperature, etc.) at physiological conditions, data are collected. 

Capillary Perfusion System for Quantitative Evaluation of Protein Adsorption and Platelet Adhesion to Artificial Surfaces... 

A capillary perfusion system has been developed for in vitro quantitation of protein adsorption and platelet accumulation on artificial surfaces under controlled... 

In summary, the capillary perfusion system represents a simple in vitrc technique for the quantitation of protein adsorption and platelet accumulation on artificial surfaces under well defined hydrodynamic conditions (0-4.,000 s ). Radioisotopic methods enable simultaneous study of platelet deposition and adsorption of one or more plasma proteins. Experiments may be performed using washed platelet suspensions or anticoagulated whole blood, platelet deposition being measured in the latter case by surface phase radioimmunoassay with a... 

We hope that this brief review has given the reader a general feeling of the development and application of CE in the separation of nucleic acids. With the advent of capillary array electrophoresis and microchip electrophoresis, as well as remarkable improvements in separation matrices, CE has become a standardized and cost-effective technique in the separation of nucleic acids. Novel thermo-responsive polymer solutions combine the merits of different monomers, and offer the possibility to fine-tune the desirable properties of polymer molecular architecture and chemical composition. Artificial entropic trapping systems obviate the use of viscous polymer solutions, and even offer fast, unattended, miniaturized, and multiplexed platforms. Optimizing the geometry of these electrophoretic systems to both increase the separation and reduce the diffusion (band broadening) is the main topic for future research. 

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