Background: This study seeks to assess the impact of a Delphi-validated educational video on improving comprehension of predatory journals among medical students and residents.
Methodology: Participants completed pre-video (11 questions) and post-video (19 questions) questionnaires on the same day after viewing our Delphi-validated video, with a subsequent follow-up assessment 30 days later (19 questions). Each of the three assessments included a core set of questions focused on predatory journals. Additionally, both post-video assessments incorporated the EDUCATOOL questionnaire.
Results: A total of 64 participants completed the survey (from a total of 83), including 51 medical students (79.6%) and 13 residents (20.3%). Analyses using Wilcoxon tests indicated that self-perceived knowledge increased from pre- to post-video (4 vs 8, p < 0.0001) and remained stable at 30 days (8 vs 7, p = 0.38). A similar trend was seen in assessment scores, with the Total Score increasing (7 vs 14.5, p < 0.0001) and sustaining at 30 days (14.5 vs 13, p = 0.92). The video received consistently high ratings across both EDUCATOOL questionnaires, with participants finding it highly relevant, engaging, and satisfactory.
Conclusion: Our Delphi-validated video enhances understanding of predatory journals and could complement U.S. NIH training guidelines.
So-called antimatter in the form of elementary particles such as positive electrons (antielectrons alias positrons) and negative protons (antiprotons) has for long been investigated by physicists. However, atoms or molecules of this exotic kind are conspicuously absent from nature. Since antimatter is believed to be symmetric with ordinary matter, the flagrant asymmetry constitutes a problem that still worries physicists and cosmologists. As first suggested by Paul Dirac in 1933, in distant parts of the universe there might be entire stars and galaxies made of antiparticles alone. Why not? This paper examines how the concepts of antiparticles and antimatter slowly migrated from particle physics to astronomy and cosmology. At around 1970 a few physicists speculated about an anti-universe separate from ours while others looked for the charge asymmetry in quantum processes in the early big-bang explosion of the universe. Others again proposed a 'plasma cosmology' that kept our world and the hypothetical world of antimatter apart. Soviet physicists and astronomers were no less interested in the problem than their colleagues in the West. The paper details the development up to the late 1970s, paying attention not only to mainstream scientific works but also to more speculative ideas, some of them very speculative. By that time the antimatter mystery remained mysterious - which is still the situation.

