Responses of leaf carbon, nitrogen, and phosphorus stoichiometry of Carex muliensis to water table drawdown in an alpine marsh on the Ruoergai Plateau, China.

Based on a field water table drawdown manipulation platform of Naleqiao marsh on the Rueorgai Plateau, we lifted in situ soil block of 1 m×1 m by 20 cm for simulating water table decline, and analyzed the response of carbon, nitrogen, and phosphorus stoichiometry in the wetland species Carex muliensis from June to September 2020. The results showed that there was no significant difference in leaf C content during the whole growing season, while N and P content gra-dually decreased along the growing season. After the drawdown of water table, the C content in leaves during the growing season was not consistent. Water table drawdown increased leaf C content in the early and middle growth stages, but changed little in the peak growth stage. Water table drawdown significantly increased leaf N content, while significantly decreased leaf P content. C:N, C:P, and N:P for leaves all increased along the whole growing period. The relative growth rate of C. muliensis was positively correlated with leaf C:N, but negatively correlated with leaf C:P and N:P. Water table drawdown significantly decreased leaf C:N, while significantly increased leaf C:P and N:P, which significantly reduced the relative growth rate of C. muliensis. The decrease of foliar P content induced by water table drawdown was the main regulating factor for the decrease of single leaf weight and specific leaf weight.

[Effect of combined acupuncture-medicine anesthesia in thyroid nodule ablation and its effect on serum ß-endorphin].

OBJECTIVE: To investigate the anesthetic effect of combined acupuncture-medicine anesthesia in microwave ablation of benign thyroid nodules and its effect on serum ß-endorphin. METHODS: A total of 60 patients who met the inclusion criteria and received microwave ablation of benign thyroid nodules were randomly divided into the treatment group and the control group, with 30 patients in each. The patients in the treatment group were given combined acupuncture-medicine anesthesia, and those in the control group were given intravenous anesthesia. The two groups were compared in terms of the sedative and analgesic effects of anesthesia, amount of anesthetics used, incidence rate of intraoperative snore and respiratory depression, and change in serum ß-endorphin level before anesthesia, before surgery, and after the surgery. RESULTS: Both groups obtained satisfactory anesthetic effects. Compared with the control group, the sedation score, the amounts of fentanyl and propofol used, the incidence rates of intraoperative snore and respiratory depression in the treatment group were obviously lower (P<0.05, P<0.01). The treatment group had an increase in serum ß-endorphin level before surgery and at the end of surgery (P<0.05), while the control group showed no significant change in serum ß-endorphin level at each time point. CONCLUSION: In microwave ablation of benign thyroid nodules, combined acupuncture-medicine anesthesia has good sedative and analgesic effects and can reduce the amounts of anesthetics used as well as the incidence rates of intraoperative snore and respiratory depression. The analgesic effect of acupuncture anesthesia is associated with increased ß-endorphin secretion.