Objective To investigate the effect of dexmedetomidine on the median effect concentration(EC50)of ropivacaine during sciatic nerve block combined with femoral nerve block in patients undergoing lower extremity surgery.Methods Patients with sciatic nerve block combined with femoral nerve block anesthesia who underwent lower extremity surgery from November 2021 to November 2023 were selected as the study objects.They were randomly divided into control group(0.9％saline),group D1(0.50 μg·kg-1 dexmedetomidine),group D2(0.75 μg·kg-1 dexmedetomidine)and group D3(1.00 μg·kg-1 dexmedetomidine).The stress response,serum pain mediators,vital signs and visual analogue scale(VAS)of patients at different time points during operation were analyzed by repeated measures ANOVA.ropivacaine EC50 was measured by sequential method,and the relationship between dexmedetomidine dose and ropivacaine EC50 was analyzed by Logistic regression.Results A total of 208 patients were include and each group was 52 patients.Compared with the same group before surgery,the stress response level of the 4 groups after surgery and 1 h after surgery was significantly decreased,and the serum pain mediators level was significantly increased(P＜0.05).Compared with the control group,the stress response and serum pain mediators levels in groups D1,D2 and D3 were more normal after surgery and 1 h after surgery,among them,group D3 was most close to the normal value(P＜0.05).There were no significant differences in blood oxygen saturation and bifrequency index of EEG among the four groups at each time point(P＞0.05).At T1 and T2,the heart rate(HR)of the control group was significantly higher than that of the group D2 and D3(P＜0.05).At T1,the control group had a significantly higher mean arterial pressure(MAP)than the other three groups,at T2,the control group had a significantly higher MAP than the group D2 and D3,and at T3,the control group had a significantly higher MAP than the group D3(P＜0.05).VAS scores in 4 groups were significantly lower after surgery and 1 h after surgery than before surgery(P＜0.05).The VAS score in group D3 was significantly lower than that in group D1 and D2(P＜0.05).Repeated measurement ANOVA showed that the effects of time on stress response and serum pain mediators were different with different anesthesia methods.The influence of time on HR,MAP and VAS scores varied with different anesthesia methods.Sequential assay results showed that the EC50 of ropivacaine in control group,group D1,group D2 and group D3 was 5.985,5.631,5.329 and 5.125 μg·mL-1,respectively.Logistic results showed that the dose of dexmedetomide was a protective factor for ropivacaine EC50 in sciatic nerve block combined with femoral nerve block in limb surgery patients(P＜0.05).Conclusion The ropivacaine EC50 can be significantly reduced by 1.00 μg·kg-1 dexmedetomidine.This is a protective factor for sciatic nerve block combined with femoral nerve block in patients undergoing lower limb surgery,and it can be applied clinically.

Objective To investigate the effect of dexmedetomidine on the median effect concentration(EC50)of ropivacaine during sciatic nerve block combined with femoral nerve block in patients undergoing lower extremity surgery.Methods Patients with sciatic nerve block combined with femoral nerve block anesthesia who underwent lower extremity surgery from November 2021 to November 2023 were selected as the study objects.They were randomly divided into control group(0.9％saline),group D1(0.50 μg·kg-1 dexmedetomidine),group D2(0.75 μg·kg-1 dexmedetomidine)and group D3(1.00 μg·kg-1 dexmedetomidine).The stress response,serum pain mediators,vital signs and visual analogue scale(VAS)of patients at different time points during operation were analyzed by repeated measures ANOVA.ropivacaine EC50 was measured by sequential method,and the relationship between dexmedetomidine dose and ropivacaine EC50 was analyzed by Logistic regression.Results A total of 208 patients were include and each group was 52 patients.Compared with the same group before surgery,the stress response level of the 4 groups after surgery and 1 h after surgery was significantly decreased,and the serum pain mediators level was significantly increased(P＜0.05).Compared with the control group,the stress response and serum pain mediators levels in groups D1,D2 and D3 were more normal after surgery and 1 h after surgery,among them,group D3 was most close to the normal value(P＜0.05).There were no significant differences in blood oxygen saturation and bifrequency index of EEG among the four groups at each time point(P＞0.05).At T1 and T2,the heart rate(HR)of the control group was significantly higher than that of the group D2 and D3(P＜0.05).At T1,the control group had a significantly higher mean arterial pressure(MAP)than the other three groups,at T2,the control group had a significantly higher MAP than the group D2 and D3,and at T3,the control group had a significantly higher MAP than the group D3(P＜0.05).VAS scores in 4 groups were significantly lower after surgery and 1 h after surgery than before surgery(P＜0.05).The VAS score in group D3 was significantly lower than that in group D1 and D2(P＜0.05).Repeated measurement ANOVA showed that the effects of time on stress response and serum pain mediators were different with different anesthesia methods.The influence of time on HR,MAP and VAS scores varied with different anesthesia methods.Sequential assay results showed that the EC50 of ropivacaine in control group,group D1,group D2 and group D3 was 5.985,5.631,5.329 and 5.125 μg·mL-1,respectively.Logistic results showed that the dose of dexmedetomide was a protective factor for ropivacaine EC50 in sciatic nerve block combined with femoral nerve block in limb surgery patients(P＜0.05).Conclusion The ropivacaine EC50 can be significantly reduced by 1.00 μg·kg-1 dexmedetomidine.This is a protective factor for sciatic nerve block combined with femoral nerve block in patients undergoing lower limb surgery,and it can be applied clinically.

Abstract Falls are the leading cause of accidental injury deaths among the elderly. Currently, the incidence and disease burden of falls among the elderly remain high. By understanding the influencing factors of falls among the elderly and formulating targeted preventive measures, the risk of falls can be effectively reduced. Studies have found that falls among the elderly are results of the interaction of multiple factors. When formulating fall prevention strategies, attention should be paid to fall risk assessment and stratification, fall prevention exercise support and health education, living environment improvement, and primary healthcare service enhancement. Reviewing publications pertaining to the epidemiological studies of falls from January 2004 to January 2024, this article summarizes the epidemiological characteristics, risk factors, prevention and control strategies of falls among the elderly, aiming to provide the reference for prevention and control.

Objective To study the effects of serum on anticancer activity of DHA and its antitumor mechanism. Method The growth inhibition of DHA on lung cancer A549 cells,and the effect of DHA on serum-induced protein kinase B(Akt)activation were assessed by MTT and Western blot respectively. Results DHA markedly induced growth inhibition of A549 cells in low concentration of serum,but promoted growth of A549 cells in high concentration of serum. DHA significantly blocked serum-induced activation of Akt in serum-free medium. Conclusion Serum is obviously against DHA-mediated growth inhibition of A549 cells,and DHA inhibits activation of Akt by lipid peroxidation and blocks growth of A549 cells.

Objective To investigate the effects of myricetin (Myr) on A549 lung cancer cell proliferation and its mechanism. Method The inhibitory effects of Myr on the growth of A549 cells were investigated and its value of IC50 after 72 h incubation was measured by 3-(4,5-dimethyl-thiazolyl -2)-2,5-diphenyl tetrazolium bromide (MTT) method. The phosphorylation level of Akt protein was studied by Western blotting. Results Myr inbibited A549 cell proliferation in dose-dependent way. The IC50 value of Myr treatment for 72 h was 41.7 ?g/ml. Treatments with 32 ?g/ml Myr for 12 h significantly reduced the protein kinase B (Akt Ser473) phosphorylation. Conclusion Myr could inhibit the growth of A549 cell in a dose-dependent way. Akt phosphorylation may be the mainly molecular target of Myr in A549.

0.05) at 8 w. At 8 w body fat and TG in groups B and C were significantly lower than group A (P