A medical hub for connecting a tubular member to a fluid source has a first structure for connecting to the fluid source, a second structure for connecting to the tubular member, and a transparent portion formed between the first and second structures. 9 wt % a first component defined by Formula 1;OmO2Formula 1wherein:x is no more than about 0. The magnetic filter further includes a magnetic tunnel junction. The active materials include, e. -%; or iso-butanol present in a concentration of 5 to 20 vol.