[Dose-response Relationship of Dexmedetomidine Combined with Sufentail for Postoperative Intravenous Analgesia in Video-assisted Thoracoscopic Surgery].

Objective To investigate the 50% effective dose(ED50)and 95% effective dose(ED95)of dexmedetomidine(DEX)combined with 0.032 µg/(kg·h)sufentanil as well as its analgesic effect for patient-controlled intravenous analgesia(PCIA)after video-assisted thoracoscopic surgery(VATS).Methods Totally 25 patients undergoing elective VATS were enrolled. DEX and 0.032 µg/(kg·h)sufentanil were used for postoperative PCIA. The loading dose of DEX was 0.048 µg/(kg·h),and the dose difference between two adjacent patients was 0.008 µg/(kg·h). The DEX dose of a current patient was determined by whether the previous patient was satisfied with postoperative analgesic effect. If the previous patient was satisfied with postoperative analgesic effect,the DEX dose of the current patient was decreased by 0.008 µg/(kg·h);and if the previous analgestic effect was not satisfactory,DEX dose of the current patient was increased by 0.008 µg/(kg·h). The study endpoint was dexmedetomidine dose was<0.008 µg/(kg· h) within 7 upper and lower cycles in 7 consecutive cases. Finally,the probability unit regression was used to estimate the ED50 and ED95 of DEX and their 95% CI.Results When DEX combined with 0.032 µg/(kg·h) sufentanil was used for postoperative PCIA in young patients undergoing VATS,the ED50 and ED95of DEX were 0.0346 µg/(kg· h)[95%CI:0.0283-0.0408 µg/(kg·h)] and 0.0459 µg/(kg·h)[95%CI:0.0400-0.0880 µg/(kg·h)],respectively. No adverse reaction such as vomiting,respiratory depression,or bradycardia occurred. The average Visual Analogue Scale(VAS)scores at rest(Z=-5.128,P=0.000)and cough(Z=-6.642,P=0.000)and the Ramsay sedation score(Z=-2.335,P=0.020)within 6 hours after surgery were higher than those after 6 hour.Conclusion DEX combined with 0.032 µg/(kg·h) sufentanil are effective for postoperative PCIA in patients undergoing VATS when the ED50 and ED95 are 0.0346 µg/(kg·h)and 0.0459 µg/(kg·h),respectively.

Effects of gas temperature on NO(x) removal by dielectric barrier discharge.

The purpose of this investigation is to discuss the effect of gas temperature on NO(x) removal by dielectric barrier discharge. The Boltzmann equation was used to analyse the electron distribution function in the reactor, and experiments were conducted to find out the effects of different temperatures. The calculation results show that, with a rise in the temperature, E/N increases, increasing the ionization rate. When the ratio of electric field strength to total gas density (E/N) rises from 50 to 150 Td, the ionization rate and electron mean energy increase by 2.0 x 10(5) and 2.3, respectively. The experiments show that in the NO/N2 system, when the temperature increases to 1 30 degrees C and the applied voltage is 11.1 kV, the discharge power is 44.7 W, which is higher than the discharge power of 35.4 W found at 25 degrees C; in the NO/O2/N2 system, an increase in the temperature increases the decomposition of active O3 species, producing a negative effect on NO oxidation; in the NO/O2/N2/C2H4 system, when the temperature increases, the quantity of active species HO2 increases and the NO removal reaction rate increases, reflecting an obvious improvement in the NO removal; and in the NO/O2/N2/C2H4/H2O system, at 25 degrees C, 90 degrees C, and 130 degrees C, when the energy density is 239.7 J L(-1), the NO removal efficiencies are 52.8%, 66.4%, and 71.0%, respectively.

[Pore structure and desulfurization characteristics of organic calcium].

Calcination of oganic calcium was carried out in fixed bed, pore structure of tested sample was analyzed with auto-adsorption analyzer, and desulfurization experiment was studied by intelligent sulfur determination analyzer. Specific surface area of calcium magnesium acetate (CMA) was 46.6 m2/g after calcination at 900 degrees C, almost four times of that of limestone. Specific surface area of calcium acetate (CA) were mainly made up of pore of diameter less than 5 nm, and those of CMA was chiefly contributed by middle pore of diameter about 5 nm. Agglomeration of CA occurred in pore of diameter less than 5 nm, while CMA was sintered in whole range of pore size distribution. Agglomeration of organic calcium were slighter. Desulfurization efficiency of organic calcium ranged from 62.28% to 75.55% at 1000 degrees C as calcium/sulfur ratio being one, which was one time more than that of limestone. Perfect pore structure of organic calcium contributes to higher desulfurization efficiency.

[Desulfurization characteristic of organic calcium at high temperature].

Aim to control the emission of SO2 during coal combustion, desulfurization characteristic of organic calcium was studied by intelligent sulfur determination analyzer. Sulfur releasing curve changed from two "peak value" to one for addition of organic calcium, with velocity of SO2 release decreasing. Efficiency of sulfur reduction was double when organic calcium was used under 1 000 degrees C compared to limestone, and reduction efficiency of calcium magnesium acetate was 73.84%. Sulfur content, furnace temperature, calcium/sulfur ratio and paticle's diameter were important factors as for desulfurizing rate. Sulfur removal efficiency was improved with coal's sulfur content increasing or particle's diameter decreasing. Decreasing degree of reduction efficiency lowered with sulfur content increasing as temperature improved. Efficiency remained high level as 59.08% by calcium magnesium acetate at 1 200 degrees C. Perfect efficiency could be reached as calcium/sulfur ratio being one and augmentation degree was inapparent with more calcium addition. Therefore organic calciums are excellent absorbent for desulfurization and calcium magnesium acetate has best sulfur removal efficiency.

[Fluorine removal efficiency of organic-calcium during coal combustion].

Effectiveness of calcium magnesium acetate (CMA) and calcium acetate(CA) as feasible HF capture were studied by means of fixed bed tube furnaces. The effects of temperature, particle diameter and Ca/S molar ratio on the fluorine removal efficiency were studied. By contract with CaCO3 at the same condition, we find that the HF capture effectiveness of those sorbents is superior to CaCO3, especially at high temperature. At 1 000 - 1 100 degrees C, the efficiency of fluorine removal during coal combustion of CMA is 1.68 - 1.74 times as that of CaCO3; the efficiency of fluorine removal during coal combustion of CA is 1.28 - 1.37 times as that of CaCO3.