RESUMO
To reveal the mechanism of plasma (assisted the ignition process of methane/air further, schematic of dielectric barrier discharge plasma system with atmospheric air was designed and set up, the emission spectrum of dielectric barrier discharge plasma with atmospheric air was measured, and the active particles produced by the interaction of dielectric barrier discharge plasma with atmospheric air were analyzed with the spectrum technology, the ignition model and calculation methods of sensitivity analysis and reaction path analysis were given, effects of NO and O3 on the ignition delay time were simulated, and the chemical kinetics mechanism of NO and O3 assisted ignition was revealed via sensitivity analysis and reaction path analysis. The results show that main excited particles of N2 and O3 are generated via effect of plasma on the atmospheric air, which are converted into active particles of NO(ξ) and O3 in the end, the life of which are longer than any other active particles, effects of plasma on the ignition is simplified as effects of NO(ξ) and O3 on the ignition; NO and O3 could reduce the ignition delay time significantly, but the amplitude decrease with increase of the initial temperature, this is because the rate of ignition is decided by the oxidation rate of CH3, the oxidized pathway of CH3 is R155 and R156 for auto-ignition and their rates are slower when temperature is low, so the ignition delay time of methane/air is longer; NO could reduce the ignition delay time significantly because of the oxidized pathway of CH3 is changed to R327 CH3O2 + NO = CH3O + NO2, R328 CH3 + NO2 = CH3O + NO for NO(ξ) (assisted ignition process from R155 and R156 for auto-ignition; and the chemical kinetic effect is the dominating factor of O3 on the ignition and which change the reaction path.
RESUMO
The measurement of nonuniform temperature and concentration distributions was investigated based on tunable diode laser absorption spectroscopy technology. Through direct scanning multiple absorption lines of H2O, two zones for temperature and concentration distribution were achieved by solving nonlinear equations by least-square fitting from numerical and experimental studies. The numerical results show that the calculated temperature and concentration have relative errors of 8.3% and 7.6% compared to the model, respectively. The calculating accuracy can be improved by increasing the number of absorption lines and reduction in unknown numbers. Compared with the thermocouple readings, the high and low temperatures have relative errors of 13.8% and 3.5% respectively. The numerical results are in agreement with the experimental results.
RESUMO
A torsional thrust stand has been developed for the study of the average thrust for microNewton pulsed thrusters. The main body of the thrust stand mainly consists of a torsional balance, a pair of flexural pivots, a capacitive displacement sensor, a calibration assembly, and an eddy current damper. The behavior of the stand was thoroughly studied. The principle of thrust measurement was analyzed. The average thrust is determined as a function of the average equilibrium angle displacement of the balance and the spring stiffness. The thrust stand has a load capacity up to 10 kg, and it can theoretically measure the force up to 609.6 µN with a resolution of 24.4 nN. The static calibrations were performed based on the calibration assembly composed of the multiturn coil and the permanent magnet. The calibration results demonstrated good repeatability (less than 0.68% FSO) and good linearity (less than 0.88% FSO). The assembly of the multiturn coil and the permanent magnet was also used as an exciter to simulate the microthruster to further research the performance of the thrust stand. Three sets of force pulses at 17, 33.5, and 55 Hz with the same amplitude and pulse width were tested. The repeatability error at each frequency was 7.04%, 1.78%, and 5.08%, respectively.
RESUMO
<p><b>OBJECTIVE</b>To explore the therapeutic effect of qi benefiting blood activating method (QB-BAM) on acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients with blood stasis syndrome (BSS) by observing its effect on plasma fibrinogen (Fg) and D-dimer (D-D) levels.</p><p><b>METHODS</b>Sixty AECOPD patients with BSS were randomly assigned to the treated group and the control group, 30 in each group. All patients received conventional therapy for AECOPD. Those in the treated group were additionally injected with Shengmai Injection and Tanshinone IIA Injection. Clinical efficacy and indices including levels of Fg, D-D, PaO2, and PaCO2 were measured and compared before and after treatment.</p><p><b>RESULTS</b>The effective rate was 93.3% (28/30 cases) in the treated group, higher than that of the control group [73.3% (22/30 cases) , P < 0.05]. There was no significant difference in all indices between the treated group and the control group before treatment (P >0.05). After treatment all indices were significantly improved in the two groups (P < 0.01). But in the treated group levels of Fg and D-D decreased more and levels of PaO2 increased more (P < 0.01). Plasma levels of Fg and D-D levels were negatively correlated with PaO2 (r = -0.493, r = -0.438, P < 0.01) before treatment, and also negatively correlated with PaO2 (r = -0.452, r = -0.325, P < 0.01, P < 0.05) after treatment, but they were not significantly correlated with PaCO2 before and after treatment (P >0.05).</p><p><b>CONCLUSIONS</b>QBBAM could play a therapeutic role in improving prethrombotic states of AECOPD patients with BSS. Plasma levels of Fg and D-D were related to the severity of AECOPD.</p>
Assuntos
Humanos , Doença Aguda , Medicamentos de Ervas Chinesas , Usos Terapêuticos , Produtos de Degradação da Fibrina e do Fibrinogênio , Fibrinogênio , Hemostáticos , Plasma , Doença Pulmonar Obstrutiva Crônica , Tratamento Farmacológico , QiRESUMO
<p><b>OBJECTIVE</b>The study aimed to develop the assay of chrysosplenetin (CHR), a metabolic inhibitor of artemisinin by UPLC-MS/MS in rat plasma and investigate the pharmacokinetics parameters of CHR.</p><p><b>METHOD</b>The plasma samples were precipitated by acetonitrile to remove the proteins. Separation was carried out on a Shim-pack XR-ODS C,18(2. 0 mm x 100 mm, 2. 2 micromp.m) column using a mobile phase containing methanol-0. 1% formic acid (87:13) using by diazepam as internal standard. Mass spectrometer with electrospray ionization (ESI) operated in the positive ion mode was used for analysis. Total analysis time was 2 min.</p><p><b>RESULT</b>The assay was linear in the range 5-5 000 microg L-1 (r =0. 999 3) with recoveries in the range from 69. 0% to 81.2% and satisfied inter-, intra- precision and accuracy. CHR after oral administration is not easy to absorb with double or multimodal peak phenomenon. The t1/2 of CHR after intravenous injection was very short and that of low, medium, and high dosage was (17. 01 +/- 8. 06) , (24. 62 +/- 4. 59), (28. 46+/- 4. 63) min, respectively.</p><p><b>CONCLUSION</b>The developed method was special, rapid, and sensitive for determination of CHR pharmacokinetics. [Key words] UPLC-MS/MS; chrysosplenetin; pharmacokinetics; plasma; rat</p>
Assuntos
Animais , Feminino , Masculino , Ratos , Artemisininas , Cromatografia Líquida de Alta Pressão , Métodos , Flavonoides , Sangue , Farmacologia , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray , Métodos , Espectrometria de Massas em TandemRESUMO
<p><b>OBJECTIVE</b>To explore the effect and the mechanism of yifei jianpi recipe (YFJPR) on patients with chronic obstructive pulmonary disease (COPD).</p><p><b>METHODS</b>Forty patients with COPD in stable phase were randomly divided into two groups, the treated group and the control group. Indexes including the total and differential count of inflammatory cell in sputum, levels of interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha), as well as the percentage of forced expiratory volume in one second in its predicted value (FEV1%) and ratio of FEV1/forced vital capacity (FVC) in patients were measured before and after treatment, and compared with those in 20 healthy subjects.</p><p><b>RESULTS</b>All the indexes measured in patients before and after treatment were significantly different from those in healthy subjects (P < 0.01). Differential count of polymorphonuclear neutrophil (PMN) and levels of IL-8 and TNF-alpha in sputum in the treated group significantly decreased after treatment (P < 0.01), while the non-PMN differential count and levels of FEV1% and FEV1/FVC significantly increased (P < 0.01). But in the control group, changes only showed in increasing of FEV1% and FEV1/FVC (P < 0.05 or P < 0.01). And the effects in the treated group were better than those in the control group (P < 0.01).</p><p><b>CONCLUSION</b>YFJPR can play a therapeutic role on patients with COPD by way of reducing the airway inflammatory reaction.</p>