as the Institute for Advanced Studies in Basic Sciences in Zanjan, have close collaboration with The International Centre for Theoretical Physics in Trieste, Italy for workshops, seminars, and summer schools. The Iranian government also offers intensely competitive but fully paid scholarships for successful applicants to pursue PhD-level studies in several foreign countries, mostly Great Britain. By early 2000, Iran allocated around 0.4% of its GDP to R&D, which ranks it "far behind industrialized societies" and the world average of 1.4%. By 2009 this ratio of research to GDP reached 0.87% and the set target is 2.5%. Rankings Five Iranian universities have been placed among the world’s top 1,000 universities announced by the Quacquarelli Symonds (QS) World University Rankings 2021. U.S. News & World Report published a global ranking for universities and institutes of higher education in 2018. The best global universities in Iran were ranked as follows: Ranking by number of publications (ISI) As per the data published on QS World University Rankings official website, Sharif University of Technology, ranked 432, Amirkabir University of Technology, ranked 498, Iran University of Science and Technology, ranked between 601 and 651, University of Tehran, ranked between 701 and 750, Shahid Beheshti University, ranked between 800 and 1000, and Shiraz University, ranked between 800 and 1000, are the top 6 Iranian universities among world-class universities. The Times Higher Education Young University Rankings website has listed the world's best universities that are aged 50 years or under in 2018. Three Iranian universities are included in the recent Times Higher Education Young University Rankings. Babol Noshirvani University of Technology, ranked 55, Isfahan University of Technology, ranked between 101 and 150, and University of Gilan ranked between 201 and 250, are among the young top universities worldwide. Medical schools ISC's most recent list of the highest-ranked universities in the medical field for 2012 is: Tehran University of Medical Sciences Shiraz University of Medical Sciences Shahid Beheshti University of Medical Sciences (Former Melli University) Isfahan University of Medical Sciences Tabriz University of Medical Sciences Mashad University of Medical Sciences Ahvaz Jundishapur University of Medical Sciences Dental schools According to the 2007 rankings the top five rated schools in the dental field in Iran are: Shahid Beheshti University of Medical Sciences Tehran University of Medical Sciences and Mashad University of Medical Sciences Isfahan University of Medical Sciences Kerman University of Medical Sciences and Shahid Sadoughi University of Medical Sciences