Electron microscopes are of three basic designs – the transmission electron microscope, scanning electron microscope and the scanning transmission electron microscope. The third one is a hybrid of the two, Specimen as the name implies. Scanning and transmission electron microscopes are similar in that each uses a beam of electrons to produce an image. However, the instruments use quite different [...]
Here is a list of seven effective physical agents that can kill infection causing organisms:- 1. Electricity 2. Sonic and Supersonic Waves 3. Alpha, Beta, and Gamma Rays 4. Electrons 5. Cathode Rays 6. X Rays 7. Distilled Water. Physical Agent # 1. Electricity: Beattie and Lewis (1920) employed a current of about 4000 volts and 2 amp. for 4 [...]
Two general types of immunity are recognized – natural immunity and acquired immunity. The word "immune" is derived from the Latin stem immuno, meaning safe, or free from. In its most general sense, the term implies a condition under which an individual is protected from disease. This does not mean, however, that one is immune to all diseases, but rather [...]