Research Frontiers 2019 6 Editor’s Note This is the 2019 issue of SPring-8/SACLA Research Frontiers that covers outstanding scientific outcomes of SPring-8 and SACLA in 2018 and 2019. The best scientific achievements are collected from more than 1,000 papers published using SPring-8 or SACLA each year. As some open journals claim, it is hard to judge the true value of a scientific paper when it is published. Even so, there are papers that attract strong attention of the researchers in the field and those that surprise specialists. The editors are picking up such papers. In this sense, this is a snapshot of science at SPring-8 and SACLA in 2019 that we will look back in future. Even if some of these papers are forgotten, they may give inspirations to readers. There is one review in this issue, which is written by Dr. Yoshinari Abe of Tokyo University of Science (recently moved to Tokyo Denki University). SPring-8 ran “The Social Interest Proposals” from 2015 through 2018. This program included many proposals in the field of cultural heritage studies. The objects of the studies spanned widely both in time and space. Results of some of these studies are described by Dr. Abe who, with Prof. Izumi Nakai, is playing a major role in synchrotron-based studies on cultural heritages in Japan. SPring-8/SACLA Research Frontiers is made of two parts. The first is scientific results (Scientific Frontiers) and the second is additional information on hard and soft infrastructures that support scientific research. Although some important numbers such as the operation time are given in the second part, other information and more complete statistical numbers on the operation of SPring-8 and SACLA are available on the website so that more updated information can be accessed ( http : //www.spring8.or.jp/en/about_us/spring8data/ ). The full text of SPring-8/SACLA Research Frontiers is also available on the SPring-8 website ( http: // www.spring8.or.jp/en ). For the list of publications produced by SPring-8 users and staff, please visit the publication database at http: // www.spring8.or.jp/en/science/ publication_database/ . On behalf of all the editors, I would like to thank those who helped us by recommending excellent research results suitable for publication in this issue, and the users and staff of SPring-8 who contributed their reports to this issue. Naoto Yagi Japan Synchrotron Radiation Research Institute (JASRI) Editorial Board Naoto YAGI (Editor in Chief) SPring-8/JASRI Shunji GOTO SPring-8/JASRI Yuichi INUBUSHI SPring-8/JASRI Shigeru KIMURA SPring-8/JASRI Toyohiko KINOSHITA SPring-8/JASRI Takashi KUMASAKA SPring-8/JASRI Yasuo OHISHI SPring-8/JASRI Norimichi SANO SPring-8/JASRI Yuden TERAOKA SPring-8/QST Tomoya URUGA SPring-8/JASRI Marcia M. OBUTI-DATÉ (Secretariat) SPring-8/JASRI