ABSTRACT
OBJECTIVE:To explore the effect of dexmedetomidine with different doses combined with ropivacaine on the bra-chial plexus block. METHODS:Totally 90 patients with upper extremity surgery of brachial plexus block were randomly divided in-to test group,control group 1 and control group 2. Test group was treated with 0.375%ropivacaine 40 ml+dexmedetomidine 100μg, brachial plexus injection;control group 1 was treated with 0.375% ropivacaine 40 ml+dexmedetomidine 50 μg,brachial plexus in-jection;and control group 2 was treated with 0.375% ropivacaine 40 ml,brachial plexus injection. Onset time of sensory and motor nerve block,block duration,postoperative pain time for the first time and pain score,analgesia duration,quality of analgesia and muscle relaxant,before anesthesia induction(T0),plasma cortisol concentrations in nerve block 10 min (T1),the start of surgery (T2)and incidence of adverse reactions were observed. RESULTS:The onset time of sensory and motor nerve block and postopera-tive pain score for the first time in test group werecontrol group 1>control group 2,plasma cortisol concentrations at T1 and T2 were higher than T0,and T2>T1>T0,test group0.05). CONCLUSIONS:Ropivacaine combined with 100 μg dexmedetomidine can effectively im-prove brachial plexus block and shorten the onset time of sensory and motor nerve block,with good safety.
ABSTRACT
In order to improve the stationary phase retention of polar solvent systems and aqueous two-phase systems (ATPSs), we designed a multiple spiral disk assembly for type-J high-speed counter-current chromatography (HSCCC). The stationary phase retention was studied under different elution modes by using two solvent systems that contained 1-butanol-acetic acid-water (4:1:5, V/V/V) and polyethylene glycol (PEG) 1000-K2HPO4-water (12.5:12.5:75, W/W/W). The best retention was obtained in L-I-T, U-O-H, L-I-H three modes by pumping lower mobile phase from inner terminal (I) to outer terminal (O), and upper mobile phase from outer terminal (O) to inner terminal (I) at a relatively high flow rate. Meanwhile, the relationship between retention percentage of the stationary phase (Sf) and various parameters such as flow-rate (F), rotation speed (w) and column temperature (T) was also studied. Sf increased with the increase of w and decreased with the increase of F. Regression analysis showed a linear relationship between Sf and F1/2/w. The influence of T on Sf was not obvious between 20 degrees C and 40 degrees C, lower temperature than 20 degrees C was not suitable for viscous ATPSs. Acceptable resolutions were achieved when it was applied for the separation of dipeptides including Leu-Tyr and Val-Tyr by using 1-butanol-acetic acid-water (4:1:5, V/V/V) solvent system. The proteins including cytochrome C and myoglobin, lysozyme and myoglobin, and fresh chicken egg-white proteins were well separated by 12.5% PEG1000-12.5% K2HPO4-75% water (pH 9.0) and 16% PEG 1000-12.5% K2HPO4-71.5% water (pH 8.0) system.