Physics Students Calculate How Long a Vampire Needs To Drink Your Blood

A bite to the neck and a clean getaway—that’s what a vampire needs. A group of physics students from the University of Leicester calculated exactly how long a vampire would need to accomplish those two things: about 6.4 minutes. They published their findings in the university’s Journal of Physics Special Topics.

Source: Physics Students Calculate How Long a Vampire Needs To Drink Your Blood

Not taking into account the anti-coagulant. 😉

Depends on the vampire type. In some movies they just chew the throat open, in others their fangs are hypodermic needles and the blood drained goes directly into the vampires bloodstream. Any of these differences would vastly affect the speed of the blood loss.

Don’t Donate Blood for a Month if You’ve Been Exposed to Zika

The Food and Drug Administration (FDA) is urging people who’ve returned from places where the Zika virus is active to refrain from donating blood for at least a month, while also recommending against the collection of blood from any region with active transmission.

Source: Don’t Donate Blood for a Month if You’ve Been Exposed to Zika

Delay for at least 4 weeks, but if in doubt – take more time rather than less.

Ponder the Physics of Chocolate Fountains During Your New Year’s Revels

New Year’s revelers will be heading out to all kinds of parties tonight, and chances are a good percentage will be tempted by the presence of a chocolate fountain—just a teensy bit of indulgence before those resolutions kick in. Perhaps those with a scientific bent could find themselves pondering, just for a moment, the complicated physics involved in all that chocolaty goodness.

Source: Ponder the Physics of Chocolate Fountains During Your New Year’s Revels

I’m going to the wrong parties… 😦

Fear Can Actually Curdle Your Blood

The next time someone refers to a horror movie as “bloodcurdling,” they might actually be kinda right. A new study shows that the fear experienced when watching scary movies is in fact associated with an increase in clotting agents in the blood.

Source: Fear Can Actually Curdle Your Blood

The fear response includes a big squirt of epinephrine which increases your heart rate and constricts blood vessels so you can run from the bear faster and bleed less when it bites. That your body also dumps clotting factors dovetails with this system nicely. What’s really surprising is that this hadn’t been recognized previously.

But I’d like to see if the findings stand up in a larger sample size.

Google Wants to Patent a Blood-Sucking Smartwatch

Just when you thought our data-driven lifestyles were getting a little weird, Google wants to make it creepy. The company just filed a patent application for a “needle-free blood draw” device that can be implanted in a wearable. It’s the vampiric smartwatch you never asked for.

Source: Google Wants to Patent a Blood-Sucking Smartwatch

The patent doesn’t describe using a needle, but by blasting a gas-powered microparticle into the skin and then drawing a small vial of blood into a pressurized container…

The first use most people think about for this is glucose monitoring, for Type 1 diabetes.  But I recently learnt that INR testing needs to be done within 4 hours of being drawn.  I don’t need that frequent monitoring, but know others who do – their longest period between INR tests was a week.  Weekly tests for me means alternating arms… 😦

That said, it’s just a patent filing.  IBM was long known for patenting without producing products.  It’s preemptive, and not how patents were intended to be used.  And I don’t particularly like that someone can patent something without a functioning prototype…

People Once Believed the Arteries And Heart Were Filled With Air

It’s not?!

Almost everything we consider common knowledge today was once a total mystery. Around the second century AD, no one in the western world knew that the arteries, veins, and heart were filled with blood. Most thought they were filled with air. Here’s how one man disproved that theory.

Source: People Once Believed the Arteries And Heart Were Filled With Air

It is my understanding that the word “artery” is derived from the Greek word for windpipe, “arteria”; so we are kind of holding on to the misconception.

One of my favourite stories about how digestion functions was learnt during a war (Napoleonic?).  Anyone could be a doctor in those days, and lots learnt from sowing up soldiers…  One soldier sustained a wound to the tummy, allowing a doctor to feed the soldier directly.  But I don’t think the soldier made it 😉

15 Things You Probably Didn’t Know About Blood

Does menstrual blood really attract bears? Why does blood look blue in your veins? And why were the first blood transfusions performed with animals? Here are 15 facts, historical and biological, you probably didn’t know about blood.

Source: 15 Things You Probably Didn’t Know About Blood

The reason horseshoe crab blood is blue is the binding agent is copper, not iron. This species is thought to be the most “ancient”, having seen Jurassic dinosaurs come and go.

After I Receive a Blood Transfusion, When Does that Blood Physiologically Become Mine?

Functionally, it remains the same.

Prior to the transfusion, tests for cell surface antigens on the donor and recipient red blood cells (RBCs) would be done to ensure no differences are present that might cause a transfusion reaction.

Both the donor blood and the recipient blood have the same oxygen-carrying properties, so from a blood-draw standpoint it all just looks like blood. In most cases, the transfused blood is also a very small part of the body’s total blood volume, and so any differences between it and the rest of the body will be nearly undetectable in your average blood draw. Of course, if there are blood type mismatches, you would see reactions between donor blood and recipient blood, but barring that, everything would be kosher. Finally, the life of red blood cells is about 120 days, and in most transfusions, the transfused blood is completely absent from the system within 60 days.

One interesting side effect can happen in the event of massive transfusion that replaces an incredibly large volume of blood. If the volume is large enough to essentially replace the patient’s own blood, then you can get something called “dilutional thrombocytopenia” since transfused blood has platelets that aren’t fully functional. This can be corrected with further transfusions, but it’s something that might actually show up in a blood draw.

What would happen if a DNA test were performed on your blood after a transfusion?

Nothing special.  Tranfused blood (meaning RBCs) doesn’t carry DNA – it is essentially saline and RBCs.  Only a minimal amount of liquid (I don’t know the composition) is added to maintain pH and osmolarity so that the RBCs aren’t destroyed.

Blood that is routinely donated is then prepared in a way that removes >99% of white blood cells (the only thing in your blood to contain DNA) and the plasma. So, really, a blood transfusion is usually an erythrocyte transfusion.

However when someone has a bone marrow (or organ) transplant, all of the blood cells created from that point (IE: white blood cells) carry the DNA of the donor, not the recipient. They never really become the recipient’s.  Yes, DNA confusion has happened.

What happens if you put the wrong blood type in to someone?

The immune system will recognize it as a foreign object and destroy it, the same way it would an agent of illness like a pathogenic bacteria. Different blood types have different antigen markers on them (which is what the letter and +/- represent), and your body will attack blood that has the wrong markers. Type O blood lacks antigen markers, which is why it’s the universal donor, while AB blood has both making it the universal acceptor (the immune system is used to all the antigen markers).