The bifunctional effect of propofol on thromboxane agonist (U46619)-induced vasoconstriction in isolated human pulmonary artery

Jianxiu Cui,Zhaojun Wang,Sujuan Kuang,Guangyan Zhang,Chunyu Deng,Jue Ma,Jianxiu Cui 대한약리학회 2017 The Korean Journal of Physiology & Pharmacology Vol.21 No.6

Propofol is known to cause vasorelaxation of several systemic vascular beds. However, its effect on the pulmonary vasculature remains controversial. In the present study, we investigated the effects of propofol on human pulmonary arteries obtained from patients who had undergone surgery. Arterial rings were mounted in a Multi-Myograph system for measurement of isometric forces. U46619 was used to induce sustained contraction of the intrapulmonary arteries, and propofol was then applied (in increments from 10-300 μM). Arteries denuded of endothelium, preincubated or not with indomethacin, were used to investigate the effects of propofol on isolated arteries. Propofol exhibited a bifunctional effect on isolated human pulmonary arteries contracted by U46619, evoking constriction at low concentrations (10-100 μM) followed by secondary relaxation (at 100-300 μM). The extent of constriction induced by propofol was higher in an endothelium-denuded group than in an endothelium-intact group. Preincubation with indomethacin abolished constriction and potentiated relaxation. The maximal relaxation was greater in the endothelium-intact than the endothelium-denuded group. Propofol also suppressed CaCl2-induced constriction in the 60 mM K+-containing Ca2+-free solution in a dose-dependent manner. Fluorescent imaging of Ca2+ using fluo- 4 showed that a 10 min incubation with propofol (10-300 μM) inhibited the Ca2+ influx into human pulmonary arterial smooth muscle cells induced by a 60 mM K+- containing Ca2+-free solution. In conclusion, propofol-induced arterial constriction appears to involve prostaglandin production by cyclooxygenase in pulmonary artery smooth muscle cells and the relaxation depends in part on endothelial function, principally on the inhibition of calcium influx through L-type voltage-operated calcium channels.

An Improved Framework for Managing Requirements Changes

Jianxiu Bai,Ying Jin,Yirui Zhang,Jing Zhang 보안공학연구지원센터 2013 International Journal of Hybrid Information Techno Vol.6 No.6

Adaptive Trajectory Tracking of Quantum Systems

Jianxiu Liu,Shuang Cong,Yaping Zhu 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

A control strategy for tracking the trajectory of a time-variant objective function in closed quantum systems is proposed in this paper. The Lyapunov stability theorem is used to design the control law. Meanwhile, the issue of singularity is discussed and the problem of large value of control field occurred during the process of tracking are solved by using an adaptive regulation algorithm of objective function. Simulation results demonstrate the effectiveness and feasibility of the method proposed. We also explore the relationship of effect between control parameters and the error of the control system.

In-site Experiments on the Swelling Characteristics of a Shield Tunnel in Expansive Clay: A Case Study

Jianxiu Wang,Jiaxing Liu,Xiaotian Liu,Yunhua Jiang,Xuezeng Liu 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.3

Expansive soil swells, softens, and disintegrates when absorbing water, whereas it shrinks when losing water. Understanding the swelling characteristics of a shield tunnel in expansive soil is important. However, most in-site experiences on the swelling characteristics of a tunnel are obtained from the NATM tunnels constructed in swelling rock using drill and blast method; most laboratory experiments or theoretical analyses on the swelling characteristics of a shield tunnel in expansive soil are under certain hypotheses which have not been verified in actual situation. To solve the problems, the Slender West Lake tunnel was selected as the background, laboratory and in-site experiments were performed to understand the swelling characteristics of a shield tunnel in expansive clay. Four experimental sections were constructed in the actual tunnel. The measuring gauges were pre-installed in the segments in factory and the segments were installed in-site to observe the actual earth pressure and temperature during construction. The influences of expansive soil to the distributions and variations of earth pressure, bending moment, and temperature were analyzed. The increasing earth pressure was divided into three stages. Large earth pressure was detected at the top, bottom, left, and right sides of the tunnel. The earth pressure at the left and right sides was larger than that at the top and bottom. Large negative bending moment was detected at the top and bottom of the tunnel, whereas large positive bending moment was detected at the left and right sides of the tunnel. The minimum bending moment appeared at 45° oblique. The largest negative bending moment was larger than the largest positive bending moment. Based on the observations, a load mode of swelling pressure for a beam-spring model was suggested. It can be referred by the similar tunnels.

Dewatering of a 32.55 m Deep Foundation Pit in MAMA Under Leakage Risk Conditions

Jianxiu Wang,Xiaotian Liu,Jiaxing Liu,Linbo Wu,Qingfeng Guo,Qian Yang 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.8

A 2,250 mm whirlpool foundation pit is located in Donghai Island, Zhanjiang City, Guangdong Province, China. The layers of theisland are composed of multi-aquifers and multi-aquitards (MAMA). The aquifers are intersected by partial aquitard lenses. A largeconfined aquifer is frequently interbedded and separated into several sub-confined aquifers by partial aquitards. In the 2,250 mmfoundation pit, the water level of two confined aquifers was reduced to satisfy excavation requirements and prevent water inrush. Construction of the 32.55 m deep foundation pit encountered MAMA and potential defects of the diaphragm wall. The pumpingwells in the second confined aquifer were used to reduce the water level to ensure the safety of bottom excavation. The pumpingwells in the first confined aquifer were used to reduce the water level under emergency conditions to prevent potential water inrushand piping from the defects of the diaphragm wall. Field pumping tests and numerical simulations were performed to determine therisk of leakage and verify the capability of the pumping wells to reduce the water level. Quicksand occurred during shallowexcavation because of leakage although the confined aquifer had been cut off and pumped for a long time. Three pumping wells wereinstalled to reduce the water level. When the foundation pit was excavated to a depth of 24 m, water inrush occurred at the middle ofthe pit bottom although the water level of the dewatered aquifer had been reduced to below the excavation face. A 90 m deepborehole was found where the underlying confined aquifer below the first aquifer induced the water inrush. Although the upper waterlevel was reduced, the high water level in the deep part still induced water inrush. The pumping wells in the second aquifer were allopened, and the water level of the underlying confined aquifer was reduced. After the water level was reduced to below the pitbottom, the borehole was filled, and the water inrush stopped. However, water inrush occurred on the cracks of the diaphragm wall aspredicted. The pre-installed pumping wells were opened to control the water inrush. The deepest foundation pit on the island wasconstructed successfully after dealing with the water inrush and leakages.

The Relaxant Effect of Propofol on Isolated Rat Intrapulmonary Arteries

Guangyan Zhang,Jianxiu Cui,Yijing Chen,Jue Ma 대한약리학회 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.5

Propofol is a widely used anesthetic. Many studies have shown that propofol has direct effects on bloodvessels, but the precise mechanism is not fully understood. Secondary intrapulmonary artery ringsfrom male rats were prepared and mounted in a Multi Myograph System. The following constrictorswere used to induce contractions in isolated artery rings: high K+ solution (60 mmol/L); U46619 solution(100 nmol/L); 5-hydroxytryptamine (5-HT; 3 μmol/L); or phenylephrine (Phe; 1 μmol/L). The relaxationeffects of propofol were tested on high K+ or U46619 precontracted rings. Propofol also was addedto induce relaxation of rings preconstricted by U46619 after pretreatment with the nitric oxide synthaseinhibitor NG-nitro-L-arginine methyl ester (L-NAME). The effects of propofol on Ca2+ influx via theL-type Ca2+ channels were evaluated by examining contraction-dependent responses to CaCl2 in theabsence or presence of propofol (10 to 300 μmol/L). High K+ solution and U46619 induced remarkablecontractions of the rings, whereas contractions induced by 5-HT and Phe were weak. Propofol induceddose-dependent relaxation of artery rings precontracted by the high K+ solution. Propofol also inducedrelaxation of rings precontracted by U46619 in an endothelium-independent way. Propofol at differentconcentrations significantly inhibited the Ca2+-induced contractions of pulmonary rings exposed to highK+-containing and Ca2+-free solution in a dose-dependent manner. Propofol relaxed vessels precontractedby the high K+ solution and U46619 in an endothelium-independent way. The mechanism forthis effect may involve inhibition of calcium influx through voltage-operated calcium channels (VOCCs)and receptor-operated calcium channels (ROCCs).

The Relaxant Effect of Propofol on Isolated Rat Intrapulmonary Arteries

Zhang, Guangyan,Cui, Jianxiu,Chen, Yijing,Ma, Jue The Korean Society of Pharmacology 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.5

Propofol is a widely used anesthetic. Many studies have shown that propofol has direct effects on blood vessels, but the precise mechanism is not fully understood. Secondary intrapulmonary artery rings from male rats were prepared and mounted in a Multi Myograph System. The following constrictors were used to induce contractions in isolated artery rings: high $K^+$ solution (60 mmol/L); U46619 solution (100 nmol/L); 5-hydroxytryptamine (5-HT; $3{\mu}mol/L$); or phenylephrine (Phe; $1{\mu}mol/L$). The relaxation effects of propofol were tested on high $K^+$ or U46619 precontracted rings. Propofol also was added to induce relaxation of rings preconstricted by U46619 after pretreatment with the nitric oxide synthase inhibitor $N^G$-nitro-L-arginine methyl ester (L-NAME). The effects of propofol on $Ca^{2+}$ influx via the L-type $Ca^{2+}$ channels were evaluated by examining contraction-dependent responses to $CaCl_2$ in the absence or presence of propofol (10 to $300{\mu}mol/L$). High $K^+$ solution and U46619 induced remarkable contractions of the rings, whereas contractions induced by 5-HT and Phe were weak. Propofol induced dose-dependent relaxation of artery rings precontracted by the high $K^+$ solution. Propofol also induced relaxation of rings precontracted by U46619 in an endothelium-independent way. Propofol at different concentrations significantly inhibited the $Ca^{2+}$-induced contractions of pulmonary rings exposed to high $K^+$-containing and $Ca^{2+}$-free solution in a dose-dependent manner. Propofol relaxed vessels precontracted by the high $K^+$ solution and U46619 in an endothelium-independent way. The mechanism for this effect may involve inhibition of calcium influx through voltage-operated calcium channels (VOCCs) and receptor-operated calcium channels (ROCCs).

Analysis of Fuzhisan and Quantitation of Baicalin and Ginsenoside Rb1 by HPLC-DAD-ELSD

Jingkun Zhao,Desheng Wang,Shurong Duan,Jianxiu Wang,Jing Bai,Wenlan Li 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.7

Fuzhisan (FZS) is a traditional Chinese medicine composed of Radix Ginseng Rubra (Araliaceae family), Scutellaria baicalensis Georgi (Labiatae family), Angelica sinensis (Oliv) Diels (Umbelliferae family), Anemone altaica Fisch. Ex C.A. Mey (Araceae family) and Glycyrrhiza uralensis (Leguminosae family). To establish the chemical fingerprint of the components of FZS and quantify the components, baicalin and ginsenoside Rb1, a high performance liquid chromatography method coupled with diode array and evaporative light scattering detectors (DAD-ELSD) was developed. Separation of 36 omponents from 12 batches of FZS was performed on a C18 column, with a mobile phase consisting of acetonitrile and 0.1% acetic acidwater, with gradient elution at a column temperature of 30℃. The optimum detection wavelength was set at 335 nm, the drift tube temperature of ELSD was set at 80℃, the carrier gas pressure was 25 psi, and the gain = 10. The similarity among 12 batches of FZS was over 0.95. Five constituents of FZS, namely baicalin, ferulic acid, and ginsenosides Rg1, Re, and Rb1, were identified based on their retention times (RT). Calibration curves for baicalin and ginsenoside Rb1 showed good linearity (r2 > 0.9992); recoveries ranged from 95% to 99%. This quantification method is reproducible and simple, and may provide a tool to assess the quality of FZS.

Deliberately Unequal Gene Sampling, A Design of Molecular Studies Tested in Lepidoptera

Soowon Cho,Andreas Zwick,Jerome Regier,Charles Mitter,Michael Cummings,Jianxiu Yao,Zaile Du,Hong Zhao,Akito Kawahara,Susan Weller,Donald Davis,Joaquin Baixeras,John Brown,Cynthia Parr 한국응용곤충학회 2010 한국응용곤충학회 학술대회논문집 Vol.2010 No.05

Seeking to improve the weak resolution of deeper divergences in an initial study based on five nuclear genes (6.6kb total) in 123 exemplars, we nearly tripled the total sequence (to 26 genes, 18.4 kb total) in one third (41) of the taxa. The expanded, deliberately incomplete data matrix consistently increased bootstrap support for previously-identified groupings, while introducing no contradictory groupings of the kind that missing data have been predicted to produce. To test the relative effectiveness of “more genes” versus “more taxa” sind that we compared two largely complete matrices, the initial 5 gene × 123 taxon and the 26 gene × 41 taxon data sets, that contain roughly equal amounts of sequence. The “more genes” data set yielded consistently, sometimes dramatically higher bootstrap support that is generally not attributable to taxon number alone. We also found that a gene-rich taxon subset provides reassuring evidence of strong underlying signal that is not obvious in subsequent larger analyses, helping to encourage and guide the search for deep relationships amid the noise of expanded taxon sampling.

Study on Oxidant in Chemical Mechanical Polishing of Copper

Xu Rui,Wang Yongsheng,Wang Yipu,Liu Haixu,Su Jianxiu 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.6

In this paper, the polishing experiment of copper was carried out. According to the experimental data, when FeCl 3 was selected as oxidant, the material removal rate increases gradually with the increase of oxidant concentration. When other conditions remain unchanged, the material removal rate with larger abrasives was higher than that of smaller abrasives, and the material removal rate of pressure 3 psi was higher than that of pressure 2 psi, and the surface roughness became smaller and smaller. When the abrasive size was 1 μm, oxidant concentration was 5 g/L and the pressure was 3 psi, the material removal rate reaches 206.9 nm/min and the surface roughness reached 8 nm. When the type of oxidant was chosen as the variable, the material removal rate of the mixture of FeCl 3 and H 2 O 2 was the highest, the maximum removal rate was 105.45 nm/min when the abrasive size was 1 μm and polishing speed was 80 r/min. The surface roughness was the smallest when FeCl 3 was used as oxidant and Ra reaches the smallest 5 nm under the conditions of the abrasive size was 1 μm and polishing speed 80 r/min. The results can be used as a reference for further research the ingredients of polishing slurry in the chemical mechanical polishing of copper.