Search results
Results from the WOW.Com Content Network
The sizes of viruses determined using this new microscope fitted in well with those estimated by filtration experiments. Viruses were expected to be small, but the range of sizes came as a surprise. Some were only a little smaller than the smallest known bacteria, and the smaller viruses were of similar sizes to complex organic molecules. [14]
Viruses were seen for the first time in the 1930s when electron microscopes were invented. These microscopes use beams of electrons instead of light, which have a much shorter wavelength and can detect objects that cannot be seen using light microscopes.
During the 20th century there were four pandemics caused by influenza virus and those that occurred in 1918, 1957 and 1968 were severe. [125] Most researchers believe that HIV originated in sub-Saharan Africa during the 20th century; [ 126 ] it is now a pandemic, with an estimated 37.9 million people now living with the disease worldwide. [ 127 ]
The so-called "hepatoencephalitis group of murine viruses" [20] were grouped into a single species named Mouse hepatitis virus, as approved in 1971. The species was merged with Rat coronavirus (discovered in 1970 [ 23 ] ) and Puffinosis coronavirus (discovered in 1982 [ 59 ] ) as Murine coronavirus in 2009.
Unlike the few Apple viruses that had come before which were essentially annoying, but did no damage, the Festering Hate series of viruses was extremely destructive, spreading to all system files it could find on the host computer (hard drive, floppy, and system memory) and then destroying everything when it could no longer find any uninfected ...
Of those, about 320,000 types of viruses infect mammals but there are just 219 known to infect humans, according to the U.S. National Library of Medicine. 52 Things You Need to Know About Viruses ...
In the 20th century many diseases both old and new were found to be caused by viruses. There were epidemics of poliomyelitis that were only controlled following the development of a vaccine in the 1950s. HIV is one of the most pathogenic new viruses to have emerged in centuries. Although scientific interest in them arose because of the diseases ...
During the 20th century there were four pandemics caused by influenza virus and those that occurred in 1918, 1957 and 1968 were severe. [63] Before its eradication, smallpox was a cause of pandemics for more than 3,000 years. [ 64 ]