I know light's speed in vacuum is constant
After inducing brain injury, cerebral edema formation occurs as a result of subtle changes in the brain water content by about 78% to 80%. Laboratory investigations, therefore, utilize precise measurement techniques to quantify the water content in defined brain samples to calculate wet weight-to-dry weight ratio such as in rodent models of cerebral injury ( ; ). The conventional technique to dry tissue is the oven-drying method, which has the main disadvantage, however, that it requires relatively large samples to ensure high accuracy (). The use of small tissue samples shows a limited precision, which identifies major errors in comparison to other techniques (). Furthermore, the heating process changes the morphology of samples in that it turns the brain into a black, hard mass. This finding suggests that the tissue is also partially burned while it dries. A large body of literature exists that describes different temperature settings: 60 °C (), 95 °C () and 104 °C (), with drying periods of either 24 h (), 72 h (; ; ), and up to 5 days ( ; ). Recently, a study introduced a freeze-drying method with a 48-h drying time as an improved procedure for small tissue samples (). To increase the speed of this drying process, centrifugal vacuum concentrators (“SpeedVac”/speed-vacuum drying), a combination of vacuum-drying and centrifugation, used to reduce the boiling temperature, were developed as a fast and less expensive alternative.
To investigate the influence of sample size on brain water content data determined by two different drying-weighing methods (vacuum drying and heat-drying), brains were removed from naïve animals under deep anesthesia with isoflurane and separated according to a standardized protocol to produce tissue samples of same size and region. The water content of each left and corresponding right hemispheric sample of each animal was quantified by speed-vacuum drying (right) and oven/heat-drying (left).
Whenever the big boys in this small mother's family make a mess, she hands them the Shark Powered Lift-Away Speed vacuum. As she catches her sons wrestling in potato chip crumbs, the siblings blame each other for the mess. When her huge husband spills soil from a plant in the entryway, all she has to do is give him a knowing look. The guys don't underestimate the power of small, they happily use the compact vacuum to deep clean their messes.Centrifugal vacuum concentrators (e.g. SpeedVac/speed-vacuum drying) are a combination of vacuum-drying and centrifugation, used to reduce the boiling temperature. These concentrators have the key advantages of improving the freeze-drying speed and maintaining the integrity of dried samples, thus, allowing e.g. DNA analyses. In the present study, we compared the heat-oven with speed-vacuum technique with regard to efficacy to remove moisture from water and brain samples and their effectiveness to distinguish treatment paradigms after experimental traumatic brain injury (TBI) caused by controlled cortical impact (CCI).Present new life style with Vacuum Blender, Quiet and Ultra High-speed Blending.
Beyond your Imagination with Kuvings High-speed Quiet VACUUM BLENDER.In a prestudy we compared the time for evaporation of water of the speed-vacuum drying method with the drying length of the heat-drying method. Preweight plastic caps with an empty weight of about 1.1 g (Eppendorf AG, Hamburg, Germany) and glass vials with an empty weight of approximately 30 g (Neo Lab Migge Laborbedarf Vertriebs GmbH, Heidelberg, Germany) were filled with 150 Î¼l or 400 Î¼l of water (Aqua, B. Braun Melsungen AG, Melsungen, Germany). We weighed the water-filled vials, using a scale with an accuracy of 0.0001 g (Scaltec SBA 32; Denver Instruments, Bohemia, NY, USA) at defined points in time before starting the drying process.In the present study the speed-vacuum-drying method was established to quantify the brain water content in small tissue samples (ranging from 30 to 160 mg). We determined the wet weight-to-dry weight ratio in naïve brain tissue and following an experimental TBI via controlled cortical impact (CCI) using different durations of speed-vacuum-drying or oven/heat-drying method.Perhaps light only appears to fluctuate in speed as vacuum fluctuations cause space and time not to be flat on the small scale. But then you need to include gravity, which in this article they didn't and therefore you aren't and string theorists don't.