To study on the Postoperative Cognitive Dysfunction: Correlations With the Gene Polymorphism and the Concentrations of Plasma Homocysteine, Folic Acid and Vitamin B12. To explore whether the gene polymorphism and the concentrations of plasma homocysteine, folic acid and vitamin B12 could be used as predictor(s) of POCD and to provide reference for POCD prevention, early detection and timely diagnosis and treatment.

Inclusion Criteria:

• Non-cardiac surgery patients;
• Age is greater than or equal to 60 years old;
• Han Nationality, mother tongue is chinese;
• The MMSE score: Illiteracy is greater than or equal to 17 points, primary school is greater than or equal to 20 points, higher secondary school is more than 24 points;
• The Geriatric Depression Scale (GDS) grade 1 or 2;
• The important function without serious heart, brain, liver, kidney, lung and other organs;
• The ASA class I or II;
• The people signed informed consent.

Exclusion Criteria:

• The diagnosis of neurological and psychiatric disorders, such as Alzheimer's disease, Parkinson's syndrome, multiple sclerosis, schizophrenia, depression, etc.;
• Had severe head and face disease, trauma history or history of surgery;
• The serious body disease and tobacco, wine and other substance abuse history;
• The presence of malignant tumor with shorter survival disease.

The investigators included 215 Male and female patients undergoing non-cardiac surgery and 30 healthy volunteers at the affiliated hospital of Xuzhou Medical University.

within six months after the trial complete