site for the university. The UCLA Medical Center made history in 1981 when Assistant Professor Michael Gottlieb first diagnosed AIDS. UCLA medical researchers also pioneered the use of positron emission tomography (PET) scanning to study brain function. Professor of Pharmacology Louis Ignarro was one of the recipients of the 1998 Nobel Prize in Physiology or Medicine for discovering the signaling cascade of nitric oxide, one of the most important molecules in cardiopulmonary physiology. The U.S. News & World Report Best Hospitals ranking for 2021 ranks UCLA Medical Center 3rd in the United States and 1st in the West. UCLA Medical Center was ranked within the top 20 in the United States for 15 out of 16 medical specialty areas examined. Research UCLA is classified among "R1: Doctoral Universities – Very high research activity" and had $1.32 billion in research expenditures in FY 2018. Rankings Global The Times Higher Education World University Rankings for 2017–2018 ranks UCLA 15th in the world for academics, No.1 US Public University for academics, and 13th in the world for reputation. In 2020, it ranked 16th among the universities around the world by SCImago Institutions Rankings. UCLA was ranked 33rd in the QS World University Rankings in 2017 and 12th in the world (10th in North America) by the Academic Ranking of World Universities (ARWU) in 2017. In 2017, the Center for World University Rankings (CWUR) ranked the university 15th in the world based on quality of education, alumni employment, quality of faculty, publications, influence, citations, broad impact, and patents. The 2017 U.S. News & World Report Best Global University Rankings report ranked UCLA 10th in the world. The CWTS Leiden ranking of universities based on scientific impact for 2017 ranks UCLA 14th in the world. The University Ranking by Academic Performance (URAP) conducted by Middle East Technical University for 2016–2017 ranked UCLA 12th in the world based on the quantity, quality and impact of research articles and citations. The Webometrics Ranking of World Universities for 2017 ranked UCLA 11th in the world based on the presence, impact, openness and excellence of its research publications. National The 2021 U.S. News & World Report Best Colleges report ranked UCLA first among public universities. The Washington Monthly ranked UCLA 22nd among national universities in 2021, with criteria based on research, community service, and social mobility. The Money Magazine Best Colleges ranking for 2015 ranked UCLA 26th in the