1.Lower limb muscle mechanics during isokinetic pedaling
Chujian CHEN ; Renhong HE ; Jianzhong FAN ; Huijuan WANG ; Dong DU
Chinese Journal of Physical Medicine and Rehabilitation 2016;38(11):836-838
Objective To document and analyze thepeak force and work during isokinetic pedaling at different linear speeds and the flexion-extension peak force ratio.Methods Thirty healthy adults were tested using the Legpress system of the IsoMED 2000 apparatus.Peak force,work and the flexion-extension peak force ratio were recorded and analyzed during isokinetic pedalingat 5 and 50 cm/s.Results The peak force applied and work done by the lower limbs were both significantly lowerwhen pedaling at 50 cm/s than at 5 cm/s.There was no significant difference in peak force or work between the left and right legs at 50 cm/s.The peak force ratio at 50 cm/s was significantly higher than at 5 cm/s.Conclusion The mechanical characteristics of the leg muscles during isokinetic pedaling vary greatly.It is advisable to choose different linear speeds or training modes accordingly.
2.Simultaneous Determination of 19 Chemical Drugs in Traditional Chinese Medicines and Health Products for Treating Rhinitis by UPLC-MS/MS
Chengxian ZHANG ; Xiaoping CHEN ; Hongxia YANG ; Chujian CHEN ; Lu ZHANG ; Weijin XU
Herald of Medicine 2018;37(3):356-360
Objective To establish a UPLC-MS/MS method for simultaneous determination of 19 chemical drugs in Traditional Chinese Medicines and health products for treating rhinitis. Methods Separation was performed on Waters ACQU-ITY UPLC BEH-C18column(2.1 mm×100 mm,1.7 μm) with 0.1% formic acid acetonitrile solution and 0.1% formic acid aque-ous solution as the mobile phase by gradient elution.The flow rate was 0.3 mL·min-1.The column temperature was set at 35 ℃. The detection was performed by the positive ion electrospray ionization (ESI+) under multiple reactions monitoring (MRM) mode. Results The linear relationships of 19 chemical drugs were good in respective ranges with correlation coefficients higher than 0.995.The average recoveries of the low,medium,and high level were in the range of 84.9%-111.1%,and the RSDs were less than 5.2%.The limits of detection (LOD) and the limits of quantitation (LOQ) were in the range of 0.03-0.78 ng·mL-1 and 0.13-1.82 ng·mL-1,respectively. Conclusion The method is convenient,rapid,accurate,and sensitive,which can be used for the determination of chemical drugs added illegally in traditional Chinese medicines and health products for treating rhini-tis.