PK/PD Study of YZJ-1139

Inclusion Criteria:

1. Young adults and elderly Chinese healthy subjects, both male and female;

2. Age: [young adult group] 18-45 years old (including the threshold value); [Elderlygroup]65~75 years old (including the cut-off value);

3. Body weight [only for young adults]: ≥50kg, BMI: 18~28kg/m2 (including the thresholdvalue);

4. Understand and sign the informed consent to participate in the study.

Exclusion Criteria:

1. History of heart, liver, lung, kidney, digestive tract, blood system,neuropsychiatric system and other diseases, including anxiety and depression, thatresearchers deem clinically significant;

2. Comprehensive physical examination, neurological examination, laboratoryexamination, ECG examination, etc. indicate that the subject has abnormalities thatare judged by the researcher as clinically significant;

3. Poor compliance with the pharmacodynamics training before administration;

4. Have taken any medication in the two weeks prior to study administration, and theinvestigator judges it may affect the evaluation results;

5. History of food and drug allergy or allergic reaction that the researcher determinesto be clinically significant;

6. Serological examination (HBsAg, anti-HCV, anti-HIV, TP-Ab) with positive results;

7. History of alcohol or drug abuse within the year prior to study administration thatthe investigators believe may have affected the results assessed in this study;

8. Frequent (> 1 time per month) use of hypnotic drugs, and screening and baselinebenzodiazepine urine screening positive;

9. Participants who need to work night shifts, stay up late, or stay at least 3 timezones away from the study site within 2 weeks before and during the study;

10. Subjects who could not maintain a regular sleep and rest schedule (get up at 6-8 amand go to sleep at 10-12 PM) within 1 week before and during the study and who werejudged by the investigator to be likely to affect the results of this study;

11. Those who could not quit smoking and alcohol drinking as required during the studyperiod or whose carbon monoxide breath test detected >7 ppm during the screeningperiod (further confirmation by urine cotinine test if deemed necessary by theinvestigators);

12. Participants who have participated in any drug clinical trial as a subject within 3months prior to study administration;

13. Patients who donated blood or blood products ≥400 mL or 2 units within three monthsprior to drug administration;

14. Those who do not agree to avoid the use of tobacco, alcohol or caffeinatedbeverages, or to avoid strenuous exercise, or to avoid other factors affecting theabsorption, distribution, metabolism or excretion of drugs within 24 hours beforeand during the trial;

15. Don't agree or is unable to refrain from eating grapefruit or other related tropicalfruits and beverages and from using St. John's Wort during the 24 hours prior to thefirst dose and during the study period;

16. Women who are pregnant or nursing, or who test positive for serum HCG before trialadministration, or who cannot/do not use investigator-approved contraception duringthe study as required;

17. Those with abnormal cognitive function assessment (MMSE less than 26 points) andjudged by the researchers to be clinically significant;

18. Subjects deemed unsuitable for this clinical study by the investigator.