ABSTRACT
Objective To evaluate the efficacy of dexmedetomidine combined with nicardipine for controlled hypotension in patients undergoing orthopedic surgery.Methods Sixty ASA Ⅰ or Ⅱ patients,aged 32-64 yr,weighing 45-76 kg,scheduled for orthopedic surgery under general anesthesia,were randomly allocated into 2 groups (n =30 each):nicardipine group (group N) and dexmedetomidine + nicardipine group (group DN).A loading dose of dexmedetomidine 1 μg/kg was injected intravenously 10 min before induction of anesthesia,followed by infusion at 0.5.μg ·kg-1 ·h-1 until 30 min before the end of operation in group DN.While the equal volume of normal saline was given in group N.BIS value was maintained at 40-49 during operation.Controlled hypotension was performed with iv infusion of nicardipine at a rate of 2.5 μg· kg-1 · min-1,MAP was reduced to 60-65 mm Hg,then the infusion rate was adjusted to maintain MAP at this level,and nicardipine infusion was stopped while closing the skin.The amount of anesthetics and nicardipine consumed,blood loss,volume of fluid infused,and allogeneic blood transfusion during operation and the operation time,emergence time and extubation time were recorded.Results No patient received allogeneic blood transfusion in both groups.Compared with group N,the amount of anesthetics and nicardipine consumed was significantly decreased,the emergence time and extubation time were significantly shortened (P ＜ 0.05),and no significant change in the volume of fluid infused and blood loss was found in group DN (P ＞ 0.05).Conclusion Dexmedetomidine combined with nicardipine can reduce the requirements for nicardipine and anesthetics during operation,shorten the time for recovery from anesthesia and improve the efficacy of nicardipine for controlled hypotension when used for controlled hypotension in patients undergoing orthopedic surgery.
ABSTRACT
The extreme microorganisms Ferroplasma spp., play an important role in bioleaching of sulphide ores at low pH value and temperatures around 50 degrees C. Without cell wall, Ferroplasma spp. is sensitive to pulp density, shearing force and heavy metal ions. Thus it is difficult to obtain their high cell density cultures, which limits the large-scale industrial application. In this paper, the optimum culture conditions of Ferroplasma thermophilum were studied by shaking culture. The results showed that the optimum culture conditions are as follows: 50 degrees C, initial pH 0.5, 50 mL working volume in 250 mL shaking-flask, inorganic nitrogen source (NH4)2SO4. The optimum combination of FeSO4.7H2O, yeast extract and peptone was determined by orthogonal experiments, including FeSO4.7H2O 40 g/L, yeast extract 0.3 g/L, peptone 0.2 g/L. Under the optimum culture conditions, the cell density was up to 6.3 x 10(7) cell/mL, and the oxidation of 40 g/L ferrous sulfate heptahydrate was finished in less than 72 hours. The results might provide information for scale-up of archaeon culture as well as its industrial application.
Subject(s)
Archaea , Cell Biology , Cell Culture Techniques , Methods , Culture Media , Hydrogen-Ion Concentration , Metallurgy , TemperatureABSTRACT
A cidithiobacillus ferrooxidans is a chemolithotrophic microorganism capable of using ferrous ions and sulphides as energy sources. This microorganism has an important role in the bioleaching of minerals. During this process, the bacteria are normally subjected to several stressing conditions, such as temperature changes, lack of nutrients or pH changes, which may affect the efficiency of the bacterial action. SELDI is a recent technology that allows for high-throughput proteomics studies. The Protein Chip SELDI technology was used to generate comparative protein profiles of A c idithiobacillus ferrooxidans grown under phosphate starvation or normal condition additionally adding Fe2+ as energy resource. There were 13 significantly differential expressed protein's peaks found by using SELDI Protein Chip technologies, which made a solid foundation for further isolation these low molecular proteins by adopting technologies such as HPLC etc.