16 research outputs found
Synergism between particle-based multiplexing and microfluidics technologies may bring diagnostics closer to the patient
In the field of medical diagnostics there is a growing need for inexpensive, accurate, and quick high-throughput assays. On the one hand, recent progress in microfluidics technologies is expected to strongly support the development of miniaturized analytical devices, which will speed up (bio)analytical assays. On the other hand, a higher throughput can be obtained by the simultaneous screening of one sample for multiple targets (multiplexing) by means of encoded particle-based assays. Multiplexing at the macro level is now common in research labs and is expected to become part of clinical diagnostics. This review aims to debate on the “added value” we can expect from (bio)analysis with particles in microfluidic devices. Technologies to (a) decode, (b) analyze, and (c) manipulate the particles are described. Special emphasis is placed on the challenges of integrating currently existing detection platforms for encoded microparticles into microdevices and on promising microtechnologies that could be used to down-scale the detection units in order to obtain compact miniaturized particle-based multiplexing platforms
First demonstration of ionization cooling by the muon ionization cooling experiment
High-brightness muon beams of energy comparable to those produced by state-of-the-art electron, proton and ion accelerators have yet to be realised. Such beams have the potential to carry the search for new phenomena in lepton-antilepton collisions to extremely high energy and also to provide uniquely well-characterised neutrino beams. A muon beam may be created through the decay of pions produced in the interaction of a proton beam with a target. To produce a high-brightness beam from such a source requires that the phase space volume occupied by the muons be reduced (cooled). Ionization cooling is the novel technique by which it is proposed to cool the beam. The Muon Ionization Cooling Experiment collaboration has constructed a section of an ionization cooling cell and used it to provide the first demonstration of ionization cooling. We present these ground-breaking measurements
The effect of repeated umbilical cord occlusions on pulmonary surfactant protein mRNA levels in the ovine fetus
Objectives
In this study we sought to determine the effect of brief repeated umbilical cord occlusions (rUCO) on surfactant protein (SP) mRNA levels in the fetal sheep lung at two different gestational ages.Methods
Fourteen fetuses at 112 to 115 days’ gestation (control n = 7, rUCO n = 7) and 15 fetuses at 130 to 133 days’ gestation (control n = 7, rUCO n = 8) were studied over 4 successive days with rUCO of 90 seconds duration performed every 30 minutes for 3 to 5 hours each day in the rUCO animals. Blood samples were collected for corticotrophin (ACTH) and cortisol measurements. Animals were killed within 1 hour of the final cord occlusion. SP-A, -B, -C, and -D mRNA levels were determined in lung tissue using a ribonuclease protection assay.Results
Cord occlusions resulted in temporary increases in circulating ACTH on day 1 with both gestational ages, but the elevations were blunted by day 4. Plasma cortisol levels increased transiently with the larger effect being observed on day 4, in particular with the near-term group. With advancing gestational age there was a significant (P <.05) increase in the level of SP-A (control 112–115 days: 0.01 ± 0.01 vs control 130–133 days: 0.07 ± 0.02 fmol/mg RNA), SP -B (control 112–115 days: 0.02 ± 0.01 vs control 130–133 days: 0.07 ± 0.01 fmol/mg RNA) and SP-C (control 112–115 days: 0.13 ± 0.09 vs control 130–133 days: 0.51 ± 0.10 fmol/mg RNA), but not SP-D mRNA levels (control 112–115 days: 0.002 ± 0.002 vs control 130–133 days: 0.01 ± 0.002 fmol/mg RNA). At 112 to 115 days, there was no significant change in any of the SP mRNA levels following rUCO compared to controls. However, the same regime of rUCO at 130 to 133 days resulted in an 85% reduction in SP-A and SP-B mRNA content and a 66% reduction in SP-C mRNA levels compared to controls.Conclusion
The surprising decrease in SP-A and SP-B mRNA levels, which contrasts with other studies, suggests intermittent asphyxial episodes impact differently on surfactant apoprotein mRNA expression than does prolonged hypoxia. <br/