I only just discovered that I actually can see who leaves me a bigger reward, you were one of them, I thoroughly want to thank you, it is such a surprise to see that, I did not expect that at all. So thank you again very much! Advice in your office, like said, green plants are the best to use, Sansevieria is the biggest oxygen giver. But it is not such a nice plant, even when it is called ladys tonques does not make it better looking ;-) You can also burn essential oil, in your case or rather in that case of sitting in the office and keeping focused, I suggest you, lemon balm and rosemary. From each 3 drops in some water on your heaters, or a special steaming or steeming, lol machine that puffs out drops, you feel better by. Good luck to you.