Half-life of antibiotics - an important factor in surgical single-dose prophylaxis; Prevention of postoperative infections in general surgery; Antibioprophylaxis in digestive surgery; Penetration of cefazolin, ceftriaxone, cefoperazone and ceftazidime into human gallbladder tissue and bile; Clinical evaluation of the value of aerobic fecal decontamination with ceftriaxone in colorectal surgery; Antibiotic prophylaxis in elective colorectal surgery; The significance of timing of administration of antibiotic prophylaxis during appendectomy; Single-dose parenteral antibiotic prophylaxis in appendectomy; Comparison of ceftriaxone and ornidazole for prophylaxis of infection in vaginal hysterectomy; Ceftriaxone vs cefoxitin for prophylaxis in abdominal operations.