If you like to see only those items that have substring 'tech' in their titles, you can do it by filtering them based on their titles, as described below.
After typing 'title:', you should enter the substring you like to filter. In the case of given example above, that substring is 'tech'. Then you should enter 'title:tech' as a filtering command.
It should also be noted that this command is the default command. That is, you can also enter this substring without typing prefix 'title:'. So when you type 'tech' alone into the edit field, Newzie interprets that as 'title:tech'.