1851
It is possible that introduction of this device may have been premature as it is believed that more experimental work is needed to establish the boundaries for fatigue in AM lattice structures .
 material: as; concept or principle: experimental; engineering feature: boundaries; machanical property: fatigue; manufacturing process: AM
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: 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:
 material: as; concept or principle: experimental; engineering feature: boundaries; machanical property: fatigue; manufacturing process: AM