Guanhe is better than others, because it is more authoritative. Chief physician of Beijing You 'an Hospital Infection Center affiliated to Capital Medical University, chief physician of Beijing STD/AIDS Clinical Diagnosis and Treatment Center, and master tutor of Capital Medical University. Li Zaicun is good at: diagnosis and treatment of AIDS; Prevention of AIDS before/after contact; Diagnosis and treatment of syphilis, gonorrhea, genital herpes, condyloma acuminatum and other sexually transmitted diseases. Chief physician, associate professor, member of AIDS Group of Tropical Diseases and Parasitic Diseases Branch of Chinese Medical Association.