4884
As a result , the micro-hardness and the yield strength of the bottom region ( 385 HV ; 745.1 ± 5.2 MPa ) are similar to those of the middle region ( 381 HV ; 752.2 ± 12.1 MPa ) , respectively .
 As, yield strength, MPa, MPa
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 As, yield strength, MPa, MPa