Push your characters to the limit without actually killing them off.
We have an irrepressible urge to push our boundaries and set records. How much further can we go, physically and mentally, before we reach our ultimate limits?
The human heart is a muscular organ that pumps blood throughout the body. It is located in the center of the chest and is about the size of a fist. The heart is divided into four chambers: two atria and two ventricles. The atria receive blood from the body and the veins, and the ventricles pump blood out to the body and the arteries.
The chambers of the heart are separated by two septa: the interatrial septum and the interventricular septum. These septa prevent blood from mixing between the different chambers of the heart.
The heart also has four valves: the tricuspid valve, the mitral valve, the aortic valve, and the pulmonary valve. These valves open and close to control the flow of blood through the heart.
Heart Diagram: Right/left Atria, Right/left Ventricles, Pulmonary Trunk, Aorta, Superior/inferior Vena Cavae, Pulmonary Veins, Coronary Sinus, Right/left Atrioventricular valves (tricuspid + bicuspid), Chordae Tendinae, Interatrial Septum, Interventricular Septum, Aortic and Pulmonary Semilunar Valves, Coronary Arteries and Cardiac Veins.
A Beginner’s Guide/Cheat Sheet to Carbohydrate Counting
Use carbohydrate counting to help keep your blood glucose levels in your target range.
Carbohydrate Counting & Diabetes
For people with diabetes, counting carbohydrates is essential to blood sugar control
In July last year, the American Red Cross declared an emergency blood shortage – it simply wasn’t receiving enough donations to help all the patients that needed blood.
Now, researchers from the University of British Columbia may have found a way to address the problem, even if people aren’t donating more: convert a less-usable blood type into one that anyone can receive.
Last August, they presented their research at a meeting of the American Chemical Society, and now the results have been published in the journal Nature Microbiology.
Blood types are different because of the sugars on the surface of the red blood cells the body creates. Type A has one type of sugar and Type B has another; Type AB has both sugars. Type O doesn’t have any sugars.
If a person receives a blood transfusion of a blood type that’s not their own, their immune system will attack and kill the donated blood cells.
For example, a person with Type A blood could never receive a Type B donation because their system would simply reject the new blood because the sugars aren’t quite right.
Because Type O blood doesn’t carry any sugars, anyone can receive it – it’s the universally accepted blood type and, therefore, highly desirable.
In the past, researchers figured out that certain enzymes (molecules that cause chemical reactions) could remove the sugars from A, B, and AB blood cells, converting them into the more useful Type O.
However, as researcher Stephen Withers noted in a press release, they hadn’t yet discovered an enzyme that was efficient, safe, and economical. Their search for that enzyme took them into the human gut.
Withers and his team already knew that the lining of the digestive tract contained the same sugars found on blood cells, and that bacterial enzymes within human feces stripped those sugars from the lining to power digestion.
Using this knowledge, the researchers were able to isolate an enzyme that strips the sugars from A and B blood types, transforming them into Type O 30 times more efficiently than any previously discovered enzyme.
For now the researchers are double-checking their findings. The next step would then be to test the enzyme in a clinical setting, which will help determine if the conversion process produces any unintended consequences.
All that extra testing could still take some time. But Withers is optimistic that his team’s enzyme could be just the breakthrough we need to ensure anyone who needs a blood donation in the future will be able to receive one.
A version of this article was originally published in August 2018.
