Systemic Thiol-Disulfide Homeostasis and Contemporaneous Menstrual Pain Intensity in Primary Dysmenorrhea: A Prospective Observational Study - Gonca Turker Engin; Mert Ishak Kaya; Duygu Tugrul Ersak; Ugurcan Zorlu; Raziye Toksoz; Elcin Islek Secen; Goktug Okyar; Salim Neselioglu (Gynecology Obstetrics & Reproductive Medicine, 2026)