ScienceIQ.com

Inkjet Printers

At the heart of every inkjet printer, whether it is a color printer or just B&W, there is an ink cartridge that gets shuttled back and forth across the page, leaving a trail of letters or colors. Upon closer inspection, however, it becomes clear that there is much more to this cartridge than meets the eye. At the bottom of the cartridge, facing the ...

Continue reading...

InkjetPrinters
Biology

Word Power of the Very Young

Before they turn 2, most children have a vocabulary of about 50 words. From 1st to 5th grades, according to some estimates, their vocabulary increases by about 30,000 words. That's 20 words a day! How ... Continue reading

WordPowerChildren
Biology

Eukaryotic Organisms

Eukaryotes include fungi, animals, and plants as well as some unicellular organisms. Eukaryotic cells are about 10 times the size of a prokaryote and can be as much as 1000 times greater in volume. ... Continue reading

EukaryoticOrganisms
Biology

The Art of Hunting

Most of us have seen a praying mantis. Two thousand species of praying mantis are scattered throughout the world, ranging in size from less than half an inch (1.27 cm) to more than five inches (12.7 ... Continue reading

PrayingMantis
Biology

Is It Sexism or Racism?

Can you judge a cat by the color of its coat? Well, you can judge the gender by the color of its coat! Only 1 in 27 orange cats are girls, and more surprisingly, only 1 in 3000 calico cats are males! ... Continue reading

SexismRacism

Facts About Angina

FactsAboutAnginaAngina is a recurring pain or discomfort in the chest that happens when some part of the heart does not receive enough blood. It is a common symptom of coronary heart disease (CHD), which occurs when vessels that carry blood to the heart become narrowed and blocked due to atherosclerosis Angina feels like a pressing or squeezing pain, usually in the chest under the breast bone, but sometimes in the shoulders, arms, neck, jaws, or back. Angina is usually precipitated by exertion. It is usually relieved within a few minutes by resting or by taking prescribed angina medicine. Episodes of angina occur when the heart's need for oxygen increases beyond the oxygen available from the blood nourishing the heart. Physical exertion is the most common trigger for angina. Other triggers can be emotional stress, extreme cold or heat, heavy meals, alcohol, and cigarette smoking.

An episode of angina is not a heart attack. Angina pain means that some of the heart muscle in not getting enough blood temporarily--for example, during exercise, when the heart has to work harder. The pain does NOT mean that the heart muscle is suffering irreversible, permanent damage. Episodes of angina seldom cause permanent damage to heart muscle. In contrast, a heart attack occurs when the blood flow to a part of the heart is suddenly and permanently cut off. This causes permanent damage to the heart muscle. Typically, the chest pain is more severe, lasts longer, and does not go away with rest or with medicine that was previously effective. It may be accompanied by indigestion, nausea, weakness, and sweating. However, the symptoms of a heart attack are varied and may be considerably milder.

When someone has a repeating but stable pattern of angina, an episode of angina does not mean that a heart attack is about to happen. Angina means that there is underlying coronary heart disease. Patients with angina are at an increased risk of heart attack compared with those who have no symptoms of cardiovascular disease, but the episode of angina is not a signal that a heart attack is about to happen. In contrast, when the pattern of angina changes--if episodes become more frequent, last longer, or occur without exercise--the risk of heart attack in subsequent days or weeks is much higher.