In the U.S., you have one year from the initial date of public disclosure to file a patent application, so you can still patent it after publishing a paper, if you don't wait too long. See 35 U.S. § 102(b)(1), https://www.law.cornell.edu/uscode/text/35/102

Professional curiosity: is that because it would be considered prior art or is there some other provision that covers that kind of thing?