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Author Question: In the 1920s, airplanes were largely curiosities and a source of entertainment. Indicate whether ... (Read 153 times) |
For about 100 years, scientists thought that peptic ulcers were caused by stress, spicy food, and alcohol. Later, researchers added stomach acid to the list of causes and began treating ulcers with antacids. Now it is known that peptic ulcers are predominantly caused by Helicobacter pylori, a spiral-shaped bacterium that normally exist in the stomach.
Side effects from substance abuse include nausea, dehydration, reduced productivitiy, and dependence. Though these effects usually worsen over time, the constant need for the substance often overcomes rational thinking.
Inotropic therapy does not have a role in the treatment of most heart failure patients. These drugs can make patients feel and function better but usually do not lengthen the predicted length of their lives.
Vaccines prevent between 2.5 and 4 million deaths every year.
Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.