[Nanometer detection of self-assembly morphology of sodium hyaluronate injection on mica].

OBJECTIVE: To detect the self-assembly morphology of sodium hyaluronate injection on mica using atomic force microscopy(AFM). METHODS: Atomic force microscopy with nanometer resolution was used to observe the self-assembly morphology of different concentrations of sodium hyaluronate injection on mica at room temperature. RESULTS: The self-assembly morphology of 0.001, 0.01, and 0.1 mg/ml sodium hyaluronate injection on mica featured piebald, reticular and dendritic structures, respectively. At 1 and 5 mg/ml, sodium hyaluronate injection displayed bacilliform and spherical structures on mica, respectively; the diameter and height of the particles of 5 mg/ml sodium hyaluronate was 197.97±78.48 nm and 30.79±18.67 nm, significantly greater than those of 0.1 mg/ml sodium hyaluronate injection (49.52±11.93 nm and 5.37±1.59 nm, respectively, P<0.05). CONCLUSION: The self-assembly morphology of sodium hyaluronate injection on mica varies with its concentration. The piebald and reticular structure may facilitate the function of sodium hyaluronate, and the dendritic feature resembles the representative model of diffusion-limited aggregation (DLA).

Evaluation of transcutaneous electroacupoint stimulation with the train-of-four mode for preventing nausea and vomiting after laparoscopic cholecystectomy.

OBJECTIVE: To evaluate the efficacy of transcutaneous electroacupoint stimulation with a train-of-four (TOF) mode for the prevention of postoperative nausea and vomiting (PONV) in the patients undergoing laparoscopic cholecystectomy. METHODS: Ninety-six ASA Grade I - II patients scheduled for laparoscopic cholecystectomy were randomized into Neiguan (P6) electroacupoint stimulation group (treated group) and a placebo control group (placement of electrodes without electroacupoint stimulation). The anesthetic regimen was standardized by needling at Neiguan on the left side and connecting the TOF peripheral nerve stimulator. The incidence of nausea, vomiting, severity, antiemetic dosage and the degree of pain were assessed at 0, 60, 120 min, and 24 h after surgery. RESULTS: The incidence of nausea and vomiting, the dose of antiemetics and the occurrence of severe nausea were all significantly lower in the treated group compared with the control group and the score for pain was obviously reduced in patients of the treated group at 24 h post-operation (P<0.05 or P<0.01). CONCLUSION: Transcutaneous electroacupoint stimulation at P6 with the TOF mode could reduce the incidence and severity of nausea and vomiting with analgesic effects.