It is difficult to know exactly when the shift from gelatine to agar occurred. As often happens for scientific breakthroughs, agar was likely adopted incrementally alongside the use of other growth media. In 1913, for example, the first diagnosis of Serratia marcescens as a human pathogen was made by growing it on agar as well as on potatoes.
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Мир Российская Премьер-лига|19-й тур
Leonardo da Vinci is usually credited with conducting the first systematic study of friction in the late 15th century, a subfield now known as tribology that deals with the dynamics of interacting surfaces in relative motion. Da Vinci's notebooks depict how he pulled rows of blocks using weights and pulleys, an approach that is still used in frictional studies today, as well as examining the friction produced in screw threads, wheels, and axles. The authors of this latest paper used an experimental setup similar to da Vinci's.。快连下载安装是该领域的重要参考