Background:Problems like body movement, respiratory depression, and complained of pain are still common phenomenon in outpatient artificial abortion general anesthesia. Oxycodone hydrochloride is a semisynthetic opioid and has a good therapeutic effect on visceral pain. We hypothesize that oxycodone hydrochloride would be superior to fentanyl in outpatient artificial abortion surgery.Methods:In this clinical trial 149 American Society of Anesthesiologists (ASA) I or II female outpatients scheduled for elective artificial abortion surgeries under general anesthesia were randomly divided into 3 groups: oxycodone hydrochloride 0.06 mg/kg group (group A), oxycodone hydrochloride 0.08 mg/kg group (group B), and control group fentanyl 2 ug/kg (group C). The primary outcome was level body movement and respiratory depression during the surgery, the second outcome included the visual analogue scale (VAS) score 30 minutes after waking.Results:A total of 120 participants completed the study, n = 40 in each group. There was no significant difference in patients’ age, body mass index (BMI), preoperative heart rate, mean arterial blood pressure, consumption dose of propofol, intraoperative body movement type and times, and duration of surgery among the 3 groups (P > .05). Comparing the incidence of intraoperative respiratory depression and SPO2 < 90% among the 3 groups, group C's was significantly higher than those of groups A and B, and the difference was statistically significant (P < .05). Group A had no difference compared with group B. In VAS score 30minutes after waking, group C was the highest, followed by group A, with group B as the lowest. The difference among the 3 groups was statistically significant (P < .05), but a difference delta less than 1 on the VAS scale is not clinically significant.Conclusion:The analgesic effect of oxycodone hydrochloride at 0.06 mg/kg applied to painless artificial abortion surgery is not superior than that of fentanyl, but the incidence of intraoperative respiratory depression and hypoxemia is significantly lower than fentanyl.

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The loading-unloading-reloading process could affect the tensile deformation of metals with the combined function of stress relaxation and work hardening, which has been reported in multiple experiments. Nevertheless, the effects of different unloading positions and unloading times have not been investigated. In this study, unloading-reloading tests on three materials (AL6061, HSLA and Q195) were conducted. The stress exhibits a rapid rise momentarily upon reloading and stabilizes afterward while the post stress-strain curve deviates up or down from the monotonic tensile curve. The ductility is enhanced by the unloading-reloading process in general. Different unloading positions and unloading times have different degrees of influence on the stretching of these metals. The effect of loading conditions on a medium manganese steel was further studied. The functions to modify the post stress-strain relationship after unloading-reloading were established.