The electrochemical behavior of Al(Ⅲ)in urea-1-butyl-3-methylimidazolium chloride-aluminum chloride(urea-BMIC-AlCl_(3))ionic liquids,and the effect of potential and temperature on the characterization of cathode prod...The electrochemical behavior of Al(Ⅲ)in urea-1-butyl-3-methylimidazolium chloride-aluminum chloride(urea-BMIC-AlCl_(3))ionic liquids,and the effect of potential and temperature on the characterization of cathode products,current efficiency and energy consumption of aluminum electrorefining have been investigated.Cyclic voltammetry showed that the electrochemical reduction of Al(Ⅲ)was a one-step three-electron-transfer irreversible reaction,and the electrochemical reaction was controlled by diffusion.The diffusion coefficient of Al(Ⅲ)in urea-BMIC-AlCl_(3)ionic liquids at 313 K was 1.94×10^(−7)cm^(2)/s.The 7075 aluminum alloy was used as an anode for electrorefining,and the cathode products were analyzed by XRD,SEM and EDS.The results from XRD analysis indicated that the main phase of the cathode products was aluminum.The results from SEM and EDS characterization revealed that the cathode product obtained by electrorefining−1.2 V(vs.Al)was dense and uniform,and the mass fraction of aluminum decreased from 99.61%to 99.10%as the experimental temperature increased from 313 K to 333 K.In this work,the optimum experimental conditions were−1.2 V(vs.Al)and 313 K.At this time,the cathode current efficiency was 97.80%,while the energy consumption was 3.72 kW·h/kg.展开更多
Cyclic voltammetry and chronopotentiometry were used to study the reaction mechanism of Pb(Ⅱ) and the co-deposition of Pb,Mg and Li on molybdenum electrodes in LiCl-KCl-PbCl2-MgCl2 melts.The diffusion coefficient o...Cyclic voltammetry and chronopotentiometry were used to study the reaction mechanism of Pb(Ⅱ) and the co-deposition of Pb,Mg and Li on molybdenum electrodes in LiCl-KCl-PbCl2-MgCl2 melts.The diffusion coefficient of lead ions in the melts was determined by different electrochemical techniques.The results obtained by cyclic voltammetry and chronopotentiometry indicated that the underpotential deposition of lithium on pre-deposited Pb leads to the formation of a liquid Li-Pb alloy,and the Mg-Li-Pb alloys are formed after the addition of MgCl2.X-ray diffraction confirmed that in the Mg-Li-Pb alloy,PbLi3,Mg2Pb and Li7Pb2 phases exist by galvanostatic electrolysis at 6.21 A/cm2 for 2 h at 873 K and the phases can be controlled by changing the concentration of PbCl2 and MgCl2.展开更多
Aim Peptides as ligands have shown the active targeting properties to the receptors like integrins, a family of receptors over-expressed in cancers. The present study was to develop and characterize two peptides modif...Aim Peptides as ligands have shown the active targeting properties to the receptors like integrins, a family of receptors over-expressed in cancers. The present study was to develop and characterize two peptides modified drug-containing liposomes. Methods Argine-glycine-aspartic acid (RGD) tripeptide and glycine-argine-glycine-aspartic acid-serine (GRGDS) pentapeptide were used for modifications on the doxorubicin-loaded sterically stabilized liposomes (SSL-doxorubicin) for the liposome preparation, RGD-SSL-doxorubicin and GRGDS-SSL-doxorubicin, respectively. Characterizations were performed by measurements of the encapsulation efficiency, particle size and zeta potential, release rates in a simulated in vivo environment, and cytotoxicity to ovarian cancer cells. Cell uptake was investigated by flow cytometry and confocal microscopy methods. Results All encapsulation efficiencies of the liposomes were above 95%, and the modifications using RGD or GRGDS did not affect the final encapsulation efficiency. Average particle sizes of the liposomes Were in the range between 105.7 ± 3.5 nm and 130.5 ± 3.0 nm, and zeta potential values were between -3.3 ± 0.3 and -6.1 ± 0.3 mV. Approximately 2/5 of doxorubicin was released from liposomes before 12 h in the simulated in vivo environment containing fetal bovine serum. Inhibitory rates to cancer cells of the modified liposomes were slightly lower as compared to free doxorubicin. Similar phenomena were observed in the uptake measured by flow cytometry and confocal assay. After uptake applying various formulations on the cancer cells, doxorubicin was mainly distributed in the nuclei of SKOV-3 cells. Conclusion Two new doxorubicin-contained liposomes were successfully prepared and modified with argine-glycine-aspartic acid (RGD) tripeptide and glycine-argine-glycine- aspartic acid-serine (GRGDS) pentapeptide. In vitro characterization indicated that modifications did not alter significantly the properties of the sterically stabilized liposomes.展开更多
Objective To investigate the effects of the topical use of aprotinin on thebasis of comprehensive blood conservations in cardiopulmonary bypass (CPB). Methods In a prospectiveclinical trial, 20 patients were randomly ...Objective To investigate the effects of the topical use of aprotinin on thebasis of comprehensive blood conservations in cardiopulmonary bypass (CPB). Methods In a prospectiveclinical trial, 20 patients were randomly divided into 2 groups. Control group: placebo was usedtopically. Aprotinin group: aprotinin was poured into the pericardial cavity before closure of thesternotomy. Before and 24h after surgery, hemoglobin (Hb), hematocrit (Hct), bleeding time (BT),clotting time (CT) and prothrombin time (PT) were measured. Meanwhile, amounts of the mediastinaldrainage and the hemoglobin loss were observed at 0, 2, 6 and 24h after operation. The samples fromthe mediastinal drainage were also collected to measure D-Dimer (D-D), tissue type plasminogenactivator (t-PA) activity, plasminogen activator inhibitor (PAI) activity and protein C (PC).Results In Aprotinin group, D-D, t-PA activity and PC were significantly reduced, compared withthose in Control group (P<0.05, P<0.05, P<0.01). On the contrary, PAI activity was significantlyincreased, compared with that in Control group. Amounts of the mediastinal drainage and thehemoglobin loss were decreased by 43% and 52%, compared with those in Control group. Conclusion Ourresults suggest that the topical use of aprotinin can have better effects on the basis ofcomprehensive moderate blood conservation.展开更多
On basis of analysis on agroforestry-animal husbandry ecosystem characters, the research explored nutrient flow model of material cycle and carbon cycle and agroforestry-animal husbandry mutualism model and supporting...On basis of analysis on agroforestry-animal husbandry ecosystem characters, the research explored nutrient flow model of material cycle and carbon cycle and agroforestry-animal husbandry mutualism model and supporting technology in Yangtze-Huaihe Region, taking Robinia pseudoacacia stand and rubber garden as an example.展开更多
To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under ...To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.展开更多
To investigate pharmacokinetics ofbaicalin after an oral administration of different Shuang-Huang-Lian (SHL) formulations to rats. Different SIlL formulations were orally administered to rats. The concentrations of ...To investigate pharmacokinetics ofbaicalin after an oral administration of different Shuang-Huang-Lian (SHL) formulations to rats. Different SIlL formulations were orally administered to rats. The concentrations of baicalin in rat plasma were determined by HPLC, the non-compartmental pharmacokinetic parameters and population pharmacokinetic parameters of baicalin were estimated by WinNonlin and NONMEM. The plasma concentration profiles of baicalin demonstrated double-peak phenomenon except for group microemulsion prescription 2. Population pharmacokinetic model developed includes four covariates, which were the effect of formulation (FORM) on CL/F and V/F, the effect of body weight (BW) on Ka, and the effect of gender (GEND) on V/F. Numbers 1 to 6 denote SHL formulation decoction, oral liquid, colloidal solution, microemulsion prescription 1, microemulsion prescription 2 and granule, respectively. The equations for the parameters are as following: CL/F = (0.432 + 0.529). e^ηCl L/h if formulation was 2 or 6, otherwise CL/F = 0.432. e^ηCl L/h ; V/F = (11.3- 4.03 - 3.87. GEND). e^ηv L if formulation was 5, otherwise V/F = (11.3 - 3.87. GEND). e^ηv L ; Ka = 0.475. [1 - 0.0223. (BW - 195.1)]. e^ηKah^-1. SHL formulations have significant effects on the nharmacokinefic narameters.展开更多
This paper reports the intrinsic-structure DC characteristics computed from the analytical electrochemical current theory of the bipolar field-effect transistor (BiFET) with two identical MOS gates on nanometer-thic...This paper reports the intrinsic-structure DC characteristics computed from the analytical electrochemical current theory of the bipolar field-effect transistor (BiFET) with two identical MOS gates on nanometer-thick pure-base of silicon with no generation-recombination-trapping. Numerical solutions are rapidly obtained for the three potential variables,electrostatic and electron and hole electrochemical potentials,to give the electron and hole surface and volume channel currents,using our cross-link two-route or zig-zag one-route recursive iteration algorithms. Boundary conditions on the three potentials dominantly affect the intrinsic-structure DC characteristics,illustrated by examples covering 20-decades of current (10-22 to 10-2 A/Square at 400cm^2/(V · s) mobility for 1.5nm gate-oxide, and 30nm-thick pure-base). Aside from the domination of carrier space-charge-limited drift current in the strong surface channels,observed in the theory is also the classical drift current saturation due to physical pinch-off of an impure-base volume channel depicted by the 1952 Shockley junction-gate field-effect transistor theory,and its extension to complete cut-off of the pure-base volume channel,due to vanishing carrier screening by the few electron and hole carriers in the pure-base,with Debye length (25mm) much larger than device dimension (25nm).展开更多
To investigate the electrochemical reduction mechanism of Ta(Ⅴ)in ethylene carbonate and aluminum chloride(EC-AlCl3)solvate ionic liquid,cyclic voltammetry experiments were conducted on a tungsten working electrode.F...To investigate the electrochemical reduction mechanism of Ta(Ⅴ)in ethylene carbonate and aluminum chloride(EC-AlCl3)solvate ionic liquid,cyclic voltammetry experiments were conducted on a tungsten working electrode.Four reduction peaks were observed in the cyclic voltammogram of the EC-AlCl3-TaCl5 ionic liquid.The reduction peaks at-0.55,-0.72,and-1.12 V(vs Al)were related to the reduction of Ta(Ⅴ)to tantalum metal by three stages including the formation of Ta(Ⅳ)and Ta(Ⅲ)complex ions.The reduction of Ta(Ⅲ)to tantalum metal was an irreversible diffusion-controlled reaction with a diffusion coefficient of 3.7×10^-7 cm^2/s at 323 K,and the diffusion activation energy was 77 k J/mol.Moreover,the cathode products at 323 K were characterized by scanning electron microscopy,energy-dispersive spectroscopy,and X-ray photoelectron spectroscopy.The results showed that tantalum metal and tantalum oxides were obtained by potentiostatic electrodeposition at-0.8 V for 2 h.展开更多
AIM: To study the effect of blocking intestinal lymphatic circulation in two-hit rats and explore the significance of intestinal lymphatic circulation in two-hit. METHODS: Wistar rats were divided equally into three g...AIM: To study the effect of blocking intestinal lymphatic circulation in two-hit rats and explore the significance of intestinal lymphatic circulation in two-hit. METHODS: Wistar rats were divided equally into three groups: mesenteric lymph duct ligation group, non- ligation group and sham group. Mesenteric lymph was diverted by ligation of mesenteric lymph duct, and the two-hit model was established by hemorrhage and lipopolysaccharide (LPS) methods. All rats were sampled for serum pre-experiment and 24 h post- experiment. The organs including kidney, liver, lung and heart were collected for pathomorphologic observation and biochemical investigation. The nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined in serum and tissue homogenate. RESULTS: Pathomorphology study showed that the structures of kidney, lung, liver and heart tissues were normal in sham group; congestion, degeneration and necrosis in non-ligation group; but only mild lesions in ligation group. After two-hits, the contents of AST, ALT, BUN, Cr and LDH-1 in the serum of non-ligation group and ligation group were obviously higher than that in pre-experiment group and sham group, but obviously lower than that in non-ligation group. The contents of NO2-/NO3-, NOS, iNOS and MDA in the serum of non- ligation group were significantly increased, compared with pre-experiment and sham group, but SOD was significantly lower. These parameters were significantly different in ligation group compared with that in sham group, but NO2-/NO3-, iNOS and MDA in ligation group were significantly lower than that in non-ligation group. CONCLUSION: Ligation of mesenteric lymph duct could improve the disturbance of organic function and morphologic damage in two-hit rats; the lymphatic mechanism in two-hit should be emphasized.展开更多
Two case reports of emergent anesthesia of critical tracheal stenosis are presented. The use of extracorporeal circu-lation may be a lifesaving method for these patients. Two patients both with severe lower tracheal s...Two case reports of emergent anesthesia of critical tracheal stenosis are presented. The use of extracorporeal circu-lation may be a lifesaving method for these patients. Two patients both with severe lower tracheal stenosis were admitted with severe inspiratory dyspnea. The first patient had a tracheal tube inserted above the stenosis in the operating room, but ventilation was unsatisfactory, high airway pressure and severe hypercarbia developed, therefore extracorporeal circulation was immediately initiated. For the second patient, we established femoral-femoral cardiopulmonary bypass prior to induction of anaesthesia, and intubated above the tracheal tumor orally under general anesthesia, then adjusted the endotracheal tube to appropriate depth after the tumor had been resected. The patient was gradually weaned from cardiopulmonary bypass. The two patients all recovered very well after surgery. Surgery is lifesaving for patients with critical tracheal stenosis, but how to ensure effective gas exchange is crucial to the anesthetic management. Extracorporeal circulation by the femoral artery and femoral vein cannulation can gain good gas exchange even if the trachea is totally obstructed. Therefore, before the induction of anesthesia, we should assess the site and degree of obstruction carefully and set up cardiopulmonary bypass to avoid exposing the patient to unexpected risks and the anesthesiologist to unexpected challenges.展开更多
SEVERE tracheal stenosis can not only cause criti- cal medical problems such as severe shortness of breath, hypoxia, and even orthopnea, but also impose overwhelming challenges on thephysicians, particularly the anest...SEVERE tracheal stenosis can not only cause criti- cal medical problems such as severe shortness of breath, hypoxia, and even orthopnea, but also impose overwhelming challenges on thephysicians, particularly the anesthesiologist. Life-threa- tening airway obstruction can make the patient's gas ex- change extremely difficult. Though several options could be offered regarding the treatment of tracheal stenosis, normally, tracheal resection and following reconstruction is the first choice for severe airway stenosis.1 Successful surgical intervention relies on the close communication and cooperation between surgeons and anesthesiologists.展开更多
The present study summarizes the results of macro-and micro-mixing characteristics in an airlift internal loop reactor with low aspect ratio(H/D≤5) using the electrolytic tracer response technique and the method of p...The present study summarizes the results of macro-and micro-mixing characteristics in an airlift internal loop reactor with low aspect ratio(H/D≤5) using the electrolytic tracer response technique and the method of parallel competing reactions respectively. The micro-mixing has never been investigated in airlift loop reactors. The dual-tip electrical conductivity probe technique is used for measurement of local bubble behavior in the reactor. The effects of several operating parameters and geometric variables are investigated. It is found that the increase in superficial gas velocity corresponds to the increase in energy input, liquid circulation velocity and shear rate, decreasing the macro-mixing time and segregation index. Moreover, it is shown that top clearance and draft diameter affect flow resistance. However, the bubble redistribution with a screen mesh on the perforated plate distributor for macro-mixing is insignificant. The top region with a high energy dissipation rate is a suitable location for feeding reactants. The analysis of present experimental data provides a valuable insight into the interaction between gas and liquid phases for mixing and improves the understanding of intrinsic roles of hydrodynamics upon the reactor design and operating parameter selection.展开更多
AIM: To investigate microvascular injury quantitatively in the small bowel with respect to cardiopulmonary bypass (CPB) and related mechanisms. METHODS: In 10 male SD rats, normothermic CPB was established and con...AIM: To investigate microvascular injury quantitatively in the small bowel with respect to cardiopulmonary bypass (CPB) and related mechanisms. METHODS: In 10 male SD rats, normothermic CPB was established and continued with a flow rate of 100-150 mL/kg per minute for 60 min, while another 10 sham-operated animals served as controls. An approximate 10-cm loop of the terminal ileum was exteriorized for observation by means of intravital fluorescence microscopy. The small bowel microcirculatory network including arterioles, capillaries, and collecting venules was observed prior to CPB, CPB 30 min, CPB 60 min, post-CPB 60 min and post-CPB 120 rain. The intestinal capillary perfusion, microvascular permeability and leukocyte adherence were also measured. RESULTS: The systemic hemodynamics remained stable throughout the experiment in both groups. In CPB animals, significant arteriolar vasoconstriction, blood velocity reduction and functional capillary density diminution were found. As concomitances, exaggerated albumin extravasation and increased leukocyte accumulation were also noted. These changes were more pronounced and there were no signs of restitution at the end of the observation period. CONCLUSION: CPB induces significant microcirculatory injury of the small bowel in rats. The major underlying mechanisms are blood flow redistribution and generalized inflammatory response associated with CPB.展开更多
A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas vel...A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas velocity, the cross areas of riser and downcomer, gas hold-up and the local frictional loss coefficient. The experimental data indicate that either increase of gas flow rate or reduction of the downcomer diameter contributes to higher liquid circulation rate. The correlation between total and the local frictional loss coefficients was also established.Effects of gas flowrate in two risers and diameter of downcomer on the liquid circulation rate were examined. The value of total frictional loss coefficient was measured as a function of the cross area of downcomer and independent of the gas flow rate. The calculated results of liquid circulation rates agreed well with the experimental data with an average relative error of 9.6%.展开更多
Objective To evaluate the outcome of off-pump coronary artery bypass grafting (OPCABG) using a bilateral internal mammary artery (BIMA) Y configuration graft to achieve total arterial myocardial revascularization....Objective To evaluate the outcome of off-pump coronary artery bypass grafting (OPCABG) using a bilateral internal mammary artery (BIMA) Y configuration graft to achieve total arterial myocardial revascularization. Methods From October 2002 to December 2008, 208 patients (196 males and 12 females) underwent OPCABG using a BIMA Y configuration graft. The average age of the patients was 56.5 ± 11.3 years, with an age range of 33-78 years. A total of 167 (80.2%) cases had triple-vessel disease. Left main stem disease was found in 33 (15.9%) cases, and double-vessel disease was found in 8 (3.9%) cases. The semi-skeletonization technique was used to harvest the two internal mammary arteries (IMAs), and then the free right internal mammary artery was connected end-to-side to the left internal mammary artery (LIMA) in situ to complete the Y configuration graft. Off-pump and sequential anastomosis methods were used to perform coronary artery bypass surgery in all patients. Graft patency was assessed intm-operatively with the HT311 transit time flowmeter. Results A total of 728 distal anastomoses were performed in 208 patients, with the average being 3.5± 1.3 per person. No one died or experienced recurrent angina within 30 days after the operation. Conclusions OPCABG using the BIMA Y graft was safe and effective to achieve total arterial revascularization. This method avoids surgical operation on the ascending aorta and other incisions.展开更多
As a frequently-used roadbed filler,soil-rock mixture is often in the environment of freeze-thaw cycles and different confining pressures.In order to study the freeze-thaw damage mechanism of elastic modulus of soil-r...As a frequently-used roadbed filler,soil-rock mixture is often in the environment of freeze-thaw cycles and different confining pressures.In order to study the freeze-thaw damage mechanism of elastic modulus of soil-rock mixtures at different confining pressures,the concept of meso-interfacial freeze-thaw damage coefficient is put forward and the meso-interfacial damage phenomenon of soil-rock mixtures caused by the freeze-thaw cycle environment is concerned;a double-inclusion embedded model for elastic modulus of soil-rock mixtures in freezing-thawing cycle is proposed.A large triaxial test was performed and the influences of confining pressure and experimental factors on elastic modulus of soil-rock mixtures were obtained,and then the accuracy of the double-inclusion embedded model to predict the elastic modulus of soil-rock mixtures in freezing-thawing cycle is verified.Experiment results showed that as to soil-rock mixtures,with the increase of confining pressure,the elastic modulus increases approximately linearly.The most crucial factors to affect the elastic modulus are rock content and compaction degree at the same confining pressure;the elastic modulus increases with the increase of rock content and compactness;as the number of freeze-thaw cycles increases,the freeze-thaw damage coefficient of meso-structural interface and the elastic modulus decrease.展开更多
Rock pillar is the key supporting component in underground engineering.During an earthquake,the key rock pillar must bear both the seismic load and the load transferred from other damaged pillars.This paper attempts t...Rock pillar is the key supporting component in underground engineering.During an earthquake,the key rock pillar must bear both the seismic load and the load transferred from other damaged pillars.This paper attempts to reveal the influence of the mainshock on damage evolution and failure characteristic of the key rock pillar during aftershocks by cyclic loading test of marble.Four levels of pre-damage stress(i.e.,10,30,50 and 70 MPa)in the first cycle were used to simulate the mainshock damage,and then cyclic stress with the same amplitude(namely 10 MPa)was conducted in the subsequent cycles to simulate the aftershock until rock failure.The results indicate that the presence of pre-damage has an obvious weakening effect on the bearing capacity and deformation resistance of rock materials during the aftershock process.Besides,the increase of pre-damage significantly changes the final failure pattern of the key rock pillar,and leads to an increase in the proportion of small-scale rock fragments.This study may contribute to understanding the seismic capacity of the unreinforced rock pillar during mainshock-aftershock seismic sequences and to optimizing the design of the key rock pillar in underground engineering.展开更多
AIM:To test the ability of penehyclidine hydrochloride (PHC) to attenuate intestinal injury in a rat cardiopulmonary bypass (CPB) model.METHODS:Male Sprague-Dawley rats were randomly divided into six groups (eight eac...AIM:To test the ability of penehyclidine hydrochloride (PHC) to attenuate intestinal injury in a rat cardiopulmonary bypass (CPB) model.METHODS:Male Sprague-Dawley rats were randomly divided into six groups (eight each):sham-operated control;sham-operated low-dose PHC control (0.6 mg/kg);sham-operated high-dose PHC control (2.0 mg/kg);CPB vehicle control;CPB low-dose PHC (0.6 mg/kg);and CPB high-dose PHC (2.0 mg/kg).Blood samples were collected from the femoral artery 2 h after CPB for determination of plasma diamine oxidase (DAO),D-lactate and endotoxin levels.Spleen,liver,mesenteric lymph nodes and lung were removed for biochemical analyses.Intestinal tissue ultrastructure was examined by electron microscopy.RESULTS:In the sham-operated groups,high-and low-dose-PHC had no significant impact on the levels of DAO,D-lactate and endotoxin,or the incidence of intestinal bacterial translocation (BT).Serum levels of DAO,D-lactate,endotoxin and the incidence of intestinal BT were significantly increased in the surgical groups,compared with the sham-operated groups (0.543 ± 0.061,5.697 ± 0.272,14.75 ± 2.46,and 0/40 vs 1.038 ± 0.252,9.377 ± 0.769,60.37 ± 5.63,and 30/40,respectively,all P < 0.05).PHC alleviated the biochemical and histopathological changes in a dosedependent manner.Serum levels of DAO,D-lactate,and endotoxin and the incidence of intestinal BT in the high-dose PHC group were significantly lower than in the low-dose PHC group (0.637 ± 0.064,6.972 ± 0.349,29.64 ± 5.49,and 14/40 vs 0.998 ± 0.062,7.835 ± 0.330,38.56 ± 4.28,and 6/40,respectively,all P < 0.05).CONCLUSION:PHC protects the structure and function of the intestinal mucosa from injury after CPB in rats.展开更多
基金Project(52004062)supported by the National Natural Science Foundation of ChinaProject(2020-MS-084)supported by the Natural Science Foundation of Liaoning Province,ChinaProject(N2125014)supported by the Fundamental Research Funds for the Central Universities,China。
文摘The electrochemical behavior of Al(Ⅲ)in urea-1-butyl-3-methylimidazolium chloride-aluminum chloride(urea-BMIC-AlCl_(3))ionic liquids,and the effect of potential and temperature on the characterization of cathode products,current efficiency and energy consumption of aluminum electrorefining have been investigated.Cyclic voltammetry showed that the electrochemical reduction of Al(Ⅲ)was a one-step three-electron-transfer irreversible reaction,and the electrochemical reaction was controlled by diffusion.The diffusion coefficient of Al(Ⅲ)in urea-BMIC-AlCl_(3)ionic liquids at 313 K was 1.94×10^(−7)cm^(2)/s.The 7075 aluminum alloy was used as an anode for electrorefining,and the cathode products were analyzed by XRD,SEM and EDS.The results from XRD analysis indicated that the main phase of the cathode products was aluminum.The results from SEM and EDS characterization revealed that the cathode product obtained by electrorefining−1.2 V(vs.Al)was dense and uniform,and the mass fraction of aluminum decreased from 99.61%to 99.10%as the experimental temperature increased from 313 K to 333 K.In this work,the optimum experimental conditions were−1.2 V(vs.Al)and 313 K.At this time,the cathode current efficiency was 97.80%,while the energy consumption was 3.72 kW·h/kg.
基金Projects(50871033,21173060,21103033) supported by the National Natural Science Foundation of ChinaProject supported by the Fundamental Research Funds for the Central Universities,ChinaProjects(2011AA03A409,2009AA050702,2007CB200906) supported by the Basic Research Foundation of Harbin Engineering University,China
文摘Cyclic voltammetry and chronopotentiometry were used to study the reaction mechanism of Pb(Ⅱ) and the co-deposition of Pb,Mg and Li on molybdenum electrodes in LiCl-KCl-PbCl2-MgCl2 melts.The diffusion coefficient of lead ions in the melts was determined by different electrochemical techniques.The results obtained by cyclic voltammetry and chronopotentiometry indicated that the underpotential deposition of lithium on pre-deposited Pb leads to the formation of a liquid Li-Pb alloy,and the Mg-Li-Pb alloys are formed after the addition of MgCl2.X-ray diffraction confirmed that in the Mg-Li-Pb alloy,PbLi3,Mg2Pb and Li7Pb2 phases exist by galvanostatic electrolysis at 6.21 A/cm2 for 2 h at 873 K and the phases can be controlled by changing the concentration of PbCl2 and MgCl2.
基金National Natural Science Foundation of China(Grant No. 30572261)the 985 Projects (Phase II) of theState Key Laboratory of Natural and Biomimetic Drugs(Peking University, China).
文摘Aim Peptides as ligands have shown the active targeting properties to the receptors like integrins, a family of receptors over-expressed in cancers. The present study was to develop and characterize two peptides modified drug-containing liposomes. Methods Argine-glycine-aspartic acid (RGD) tripeptide and glycine-argine-glycine-aspartic acid-serine (GRGDS) pentapeptide were used for modifications on the doxorubicin-loaded sterically stabilized liposomes (SSL-doxorubicin) for the liposome preparation, RGD-SSL-doxorubicin and GRGDS-SSL-doxorubicin, respectively. Characterizations were performed by measurements of the encapsulation efficiency, particle size and zeta potential, release rates in a simulated in vivo environment, and cytotoxicity to ovarian cancer cells. Cell uptake was investigated by flow cytometry and confocal microscopy methods. Results All encapsulation efficiencies of the liposomes were above 95%, and the modifications using RGD or GRGDS did not affect the final encapsulation efficiency. Average particle sizes of the liposomes Were in the range between 105.7 ± 3.5 nm and 130.5 ± 3.0 nm, and zeta potential values were between -3.3 ± 0.3 and -6.1 ± 0.3 mV. Approximately 2/5 of doxorubicin was released from liposomes before 12 h in the simulated in vivo environment containing fetal bovine serum. Inhibitory rates to cancer cells of the modified liposomes were slightly lower as compared to free doxorubicin. Similar phenomena were observed in the uptake measured by flow cytometry and confocal assay. After uptake applying various formulations on the cancer cells, doxorubicin was mainly distributed in the nuclei of SKOV-3 cells. Conclusion Two new doxorubicin-contained liposomes were successfully prepared and modified with argine-glycine-aspartic acid (RGD) tripeptide and glycine-argine-glycine- aspartic acid-serine (GRGDS) pentapeptide. In vitro characterization indicated that modifications did not alter significantly the properties of the sterically stabilized liposomes.
基金Supported by the Jiangsu Health Bureau Grand (B9606)
文摘Objective To investigate the effects of the topical use of aprotinin on thebasis of comprehensive blood conservations in cardiopulmonary bypass (CPB). Methods In a prospectiveclinical trial, 20 patients were randomly divided into 2 groups. Control group: placebo was usedtopically. Aprotinin group: aprotinin was poured into the pericardial cavity before closure of thesternotomy. Before and 24h after surgery, hemoglobin (Hb), hematocrit (Hct), bleeding time (BT),clotting time (CT) and prothrombin time (PT) were measured. Meanwhile, amounts of the mediastinaldrainage and the hemoglobin loss were observed at 0, 2, 6 and 24h after operation. The samples fromthe mediastinal drainage were also collected to measure D-Dimer (D-D), tissue type plasminogenactivator (t-PA) activity, plasminogen activator inhibitor (PAI) activity and protein C (PC).Results In Aprotinin group, D-D, t-PA activity and PC were significantly reduced, compared withthose in Control group (P<0.05, P<0.05, P<0.01). On the contrary, PAI activity was significantlyincreased, compared with that in Control group. Amounts of the mediastinal drainage and thehemoglobin loss were decreased by 43% and 52%, compared with those in Control group. Conclusion Ourresults suggest that the topical use of aprotinin can have better effects on the basis ofcomprehensive moderate blood conservation.
基金Supported by the National S&T Support Program during the Twelfth Five-year Pla Period(2012BAD14B13)~~
文摘On basis of analysis on agroforestry-animal husbandry ecosystem characters, the research explored nutrient flow model of material cycle and carbon cycle and agroforestry-animal husbandry mutualism model and supporting technology in Yangtze-Huaihe Region, taking Robinia pseudoacacia stand and rubber garden as an example.
文摘To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.
基金National Natural Science Foundation of China (Grant No. 30472195)
文摘To investigate pharmacokinetics ofbaicalin after an oral administration of different Shuang-Huang-Lian (SHL) formulations to rats. Different SIlL formulations were orally administered to rats. The concentrations of baicalin in rat plasma were determined by HPLC, the non-compartmental pharmacokinetic parameters and population pharmacokinetic parameters of baicalin were estimated by WinNonlin and NONMEM. The plasma concentration profiles of baicalin demonstrated double-peak phenomenon except for group microemulsion prescription 2. Population pharmacokinetic model developed includes four covariates, which were the effect of formulation (FORM) on CL/F and V/F, the effect of body weight (BW) on Ka, and the effect of gender (GEND) on V/F. Numbers 1 to 6 denote SHL formulation decoction, oral liquid, colloidal solution, microemulsion prescription 1, microemulsion prescription 2 and granule, respectively. The equations for the parameters are as following: CL/F = (0.432 + 0.529). e^ηCl L/h if formulation was 2 or 6, otherwise CL/F = 0.432. e^ηCl L/h ; V/F = (11.3- 4.03 - 3.87. GEND). e^ηv L if formulation was 5, otherwise V/F = (11.3 - 3.87. GEND). e^ηv L ; Ka = 0.475. [1 - 0.0223. (BW - 195.1)]. e^ηKah^-1. SHL formulations have significant effects on the nharmacokinefic narameters.
文摘This paper reports the intrinsic-structure DC characteristics computed from the analytical electrochemical current theory of the bipolar field-effect transistor (BiFET) with two identical MOS gates on nanometer-thick pure-base of silicon with no generation-recombination-trapping. Numerical solutions are rapidly obtained for the three potential variables,electrostatic and electron and hole electrochemical potentials,to give the electron and hole surface and volume channel currents,using our cross-link two-route or zig-zag one-route recursive iteration algorithms. Boundary conditions on the three potentials dominantly affect the intrinsic-structure DC characteristics,illustrated by examples covering 20-decades of current (10-22 to 10-2 A/Square at 400cm^2/(V · s) mobility for 1.5nm gate-oxide, and 30nm-thick pure-base). Aside from the domination of carrier space-charge-limited drift current in the strong surface channels,observed in the theory is also the classical drift current saturation due to physical pinch-off of an impure-base volume channel depicted by the 1952 Shockley junction-gate field-effect transistor theory,and its extension to complete cut-off of the pure-base volume channel,due to vanishing carrier screening by the few electron and hole carriers in the pure-base,with Debye length (25mm) much larger than device dimension (25nm).
基金Projects(N182503033N172502003)supported by the Fundamental Research Funds for the Central Universities,China+1 种基金Project(2018M640258)supported by Postdoctoral Research Foundation of ChinaProject(GUIKE AA18118030)supported by Guangxi Innovation-driven Development Program,China。
文摘To investigate the electrochemical reduction mechanism of Ta(Ⅴ)in ethylene carbonate and aluminum chloride(EC-AlCl3)solvate ionic liquid,cyclic voltammetry experiments were conducted on a tungsten working electrode.Four reduction peaks were observed in the cyclic voltammogram of the EC-AlCl3-TaCl5 ionic liquid.The reduction peaks at-0.55,-0.72,and-1.12 V(vs Al)were related to the reduction of Ta(Ⅴ)to tantalum metal by three stages including the formation of Ta(Ⅳ)and Ta(Ⅲ)complex ions.The reduction of Ta(Ⅲ)to tantalum metal was an irreversible diffusion-controlled reaction with a diffusion coefficient of 3.7×10^-7 cm^2/s at 323 K,and the diffusion activation energy was 77 k J/mol.Moreover,the cathode products at 323 K were characterized by scanning electron microscopy,energy-dispersive spectroscopy,and X-ray photoelectron spectroscopy.The results showed that tantalum metal and tantalum oxides were obtained by potentiostatic electrodeposition at-0.8 V for 2 h.
基金Supported by National Science Foundation of China, No. 30370561Natural Science Foundation of Hebei Province, No. C2004000649
文摘AIM: To study the effect of blocking intestinal lymphatic circulation in two-hit rats and explore the significance of intestinal lymphatic circulation in two-hit. METHODS: Wistar rats were divided equally into three groups: mesenteric lymph duct ligation group, non- ligation group and sham group. Mesenteric lymph was diverted by ligation of mesenteric lymph duct, and the two-hit model was established by hemorrhage and lipopolysaccharide (LPS) methods. All rats were sampled for serum pre-experiment and 24 h post- experiment. The organs including kidney, liver, lung and heart were collected for pathomorphologic observation and biochemical investigation. The nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined in serum and tissue homogenate. RESULTS: Pathomorphology study showed that the structures of kidney, lung, liver and heart tissues were normal in sham group; congestion, degeneration and necrosis in non-ligation group; but only mild lesions in ligation group. After two-hits, the contents of AST, ALT, BUN, Cr and LDH-1 in the serum of non-ligation group and ligation group were obviously higher than that in pre-experiment group and sham group, but obviously lower than that in non-ligation group. The contents of NO2-/NO3-, NOS, iNOS and MDA in the serum of non- ligation group were significantly increased, compared with pre-experiment and sham group, but SOD was significantly lower. These parameters were significantly different in ligation group compared with that in sham group, but NO2-/NO3-, iNOS and MDA in ligation group were significantly lower than that in non-ligation group. CONCLUSION: Ligation of mesenteric lymph duct could improve the disturbance of organic function and morphologic damage in two-hit rats; the lymphatic mechanism in two-hit should be emphasized.
文摘Two case reports of emergent anesthesia of critical tracheal stenosis are presented. The use of extracorporeal circu-lation may be a lifesaving method for these patients. Two patients both with severe lower tracheal stenosis were admitted with severe inspiratory dyspnea. The first patient had a tracheal tube inserted above the stenosis in the operating room, but ventilation was unsatisfactory, high airway pressure and severe hypercarbia developed, therefore extracorporeal circulation was immediately initiated. For the second patient, we established femoral-femoral cardiopulmonary bypass prior to induction of anaesthesia, and intubated above the tracheal tumor orally under general anesthesia, then adjusted the endotracheal tube to appropriate depth after the tumor had been resected. The patient was gradually weaned from cardiopulmonary bypass. The two patients all recovered very well after surgery. Surgery is lifesaving for patients with critical tracheal stenosis, but how to ensure effective gas exchange is crucial to the anesthetic management. Extracorporeal circulation by the femoral artery and femoral vein cannulation can gain good gas exchange even if the trachea is totally obstructed. Therefore, before the induction of anesthesia, we should assess the site and degree of obstruction carefully and set up cardiopulmonary bypass to avoid exposing the patient to unexpected risks and the anesthesiologist to unexpected challenges.
文摘SEVERE tracheal stenosis can not only cause criti- cal medical problems such as severe shortness of breath, hypoxia, and even orthopnea, but also impose overwhelming challenges on thephysicians, particularly the anesthesiologist. Life-threa- tening airway obstruction can make the patient's gas ex- change extremely difficult. Though several options could be offered regarding the treatment of tracheal stenosis, normally, tracheal resection and following reconstruction is the first choice for severe airway stenosis.1 Successful surgical intervention relies on the close communication and cooperation between surgeons and anesthesiologists.
基金Supported by the National Basic Research Program of China(2012CB224806)the National Science Fund for Distinguished Young Scholars(21025627)+2 种基金the National Natural Science Foundation of China(21206166,20990224)the National High Technology Research and Development Program of China(2012AA03A606)Beijing Natural Science Foundation(2112038)
文摘The present study summarizes the results of macro-and micro-mixing characteristics in an airlift internal loop reactor with low aspect ratio(H/D≤5) using the electrolytic tracer response technique and the method of parallel competing reactions respectively. The micro-mixing has never been investigated in airlift loop reactors. The dual-tip electrical conductivity probe technique is used for measurement of local bubble behavior in the reactor. The effects of several operating parameters and geometric variables are investigated. It is found that the increase in superficial gas velocity corresponds to the increase in energy input, liquid circulation velocity and shear rate, decreasing the macro-mixing time and segregation index. Moreover, it is shown that top clearance and draft diameter affect flow resistance. However, the bubble redistribution with a screen mesh on the perforated plate distributor for macro-mixing is insignificant. The top region with a high energy dissipation rate is a suitable location for feeding reactants. The analysis of present experimental data provides a valuable insight into the interaction between gas and liquid phases for mixing and improves the understanding of intrinsic roles of hydrodynamics upon the reactor design and operating parameter selection.
文摘AIM: To investigate microvascular injury quantitatively in the small bowel with respect to cardiopulmonary bypass (CPB) and related mechanisms. METHODS: In 10 male SD rats, normothermic CPB was established and continued with a flow rate of 100-150 mL/kg per minute for 60 min, while another 10 sham-operated animals served as controls. An approximate 10-cm loop of the terminal ileum was exteriorized for observation by means of intravital fluorescence microscopy. The small bowel microcirculatory network including arterioles, capillaries, and collecting venules was observed prior to CPB, CPB 30 min, CPB 60 min, post-CPB 60 min and post-CPB 120 rain. The intestinal capillary perfusion, microvascular permeability and leukocyte adherence were also measured. RESULTS: The systemic hemodynamics remained stable throughout the experiment in both groups. In CPB animals, significant arteriolar vasoconstriction, blood velocity reduction and functional capillary density diminution were found. As concomitances, exaggerated albumin extravasation and increased leukocyte accumulation were also noted. These changes were more pronounced and there were no signs of restitution at the end of the observation period. CONCLUSION: CPB induces significant microcirculatory injury of the small bowel in rats. The major underlying mechanisms are blood flow redistribution and generalized inflammatory response associated with CPB.
基金Supported by Liaoning Provincial Natural Science Foundation(No.972050).
文摘A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas velocity, the cross areas of riser and downcomer, gas hold-up and the local frictional loss coefficient. The experimental data indicate that either increase of gas flow rate or reduction of the downcomer diameter contributes to higher liquid circulation rate. The correlation between total and the local frictional loss coefficients was also established.Effects of gas flowrate in two risers and diameter of downcomer on the liquid circulation rate were examined. The value of total frictional loss coefficient was measured as a function of the cross area of downcomer and independent of the gas flow rate. The calculated results of liquid circulation rates agreed well with the experimental data with an average relative error of 9.6%.
文摘Objective To evaluate the outcome of off-pump coronary artery bypass grafting (OPCABG) using a bilateral internal mammary artery (BIMA) Y configuration graft to achieve total arterial myocardial revascularization. Methods From October 2002 to December 2008, 208 patients (196 males and 12 females) underwent OPCABG using a BIMA Y configuration graft. The average age of the patients was 56.5 ± 11.3 years, with an age range of 33-78 years. A total of 167 (80.2%) cases had triple-vessel disease. Left main stem disease was found in 33 (15.9%) cases, and double-vessel disease was found in 8 (3.9%) cases. The semi-skeletonization technique was used to harvest the two internal mammary arteries (IMAs), and then the free right internal mammary artery was connected end-to-side to the left internal mammary artery (LIMA) in situ to complete the Y configuration graft. Off-pump and sequential anastomosis methods were used to perform coronary artery bypass surgery in all patients. Graft patency was assessed intm-operatively with the HT311 transit time flowmeter. Results A total of 728 distal anastomoses were performed in 208 patients, with the average being 3.5± 1.3 per person. No one died or experienced recurrent angina within 30 days after the operation. Conclusions OPCABG using the BIMA Y graft was safe and effective to achieve total arterial revascularization. This method avoids surgical operation on the ascending aorta and other incisions.
基金Project(50908234)supported by the National Natural Science Foundation of China
文摘As a frequently-used roadbed filler,soil-rock mixture is often in the environment of freeze-thaw cycles and different confining pressures.In order to study the freeze-thaw damage mechanism of elastic modulus of soil-rock mixtures at different confining pressures,the concept of meso-interfacial freeze-thaw damage coefficient is put forward and the meso-interfacial damage phenomenon of soil-rock mixtures caused by the freeze-thaw cycle environment is concerned;a double-inclusion embedded model for elastic modulus of soil-rock mixtures in freezing-thawing cycle is proposed.A large triaxial test was performed and the influences of confining pressure and experimental factors on elastic modulus of soil-rock mixtures were obtained,and then the accuracy of the double-inclusion embedded model to predict the elastic modulus of soil-rock mixtures in freezing-thawing cycle is verified.Experiment results showed that as to soil-rock mixtures,with the increase of confining pressure,the elastic modulus increases approximately linearly.The most crucial factors to affect the elastic modulus are rock content and compaction degree at the same confining pressure;the elastic modulus increases with the increase of rock content and compactness;as the number of freeze-thaw cycles increases,the freeze-thaw damage coefficient of meso-structural interface and the elastic modulus decrease.
基金Project(2022MD713784) supported by China Postdoctoral ScienceProject (1960321032) supported by the Research Start-up Fund Project for High-level Talents Introduction,ChinaProject (1609722058) supported by Xi’ an University of Architecture and Technology,China。
文摘Rock pillar is the key supporting component in underground engineering.During an earthquake,the key rock pillar must bear both the seismic load and the load transferred from other damaged pillars.This paper attempts to reveal the influence of the mainshock on damage evolution and failure characteristic of the key rock pillar during aftershocks by cyclic loading test of marble.Four levels of pre-damage stress(i.e.,10,30,50 and 70 MPa)in the first cycle were used to simulate the mainshock damage,and then cyclic stress with the same amplitude(namely 10 MPa)was conducted in the subsequent cycles to simulate the aftershock until rock failure.The results indicate that the presence of pre-damage has an obvious weakening effect on the bearing capacity and deformation resistance of rock materials during the aftershock process.Besides,the increase of pre-damage significantly changes the final failure pattern of the key rock pillar,and leads to an increase in the proportion of small-scale rock fragments.This study may contribute to understanding the seismic capacity of the unreinforced rock pillar during mainshock-aftershock seismic sequences and to optimizing the design of the key rock pillar in underground engineering.
基金Supported by A grant from the Doctor Priming Foundation of Liaoning Province,No. 20091099
文摘AIM:To test the ability of penehyclidine hydrochloride (PHC) to attenuate intestinal injury in a rat cardiopulmonary bypass (CPB) model.METHODS:Male Sprague-Dawley rats were randomly divided into six groups (eight each):sham-operated control;sham-operated low-dose PHC control (0.6 mg/kg);sham-operated high-dose PHC control (2.0 mg/kg);CPB vehicle control;CPB low-dose PHC (0.6 mg/kg);and CPB high-dose PHC (2.0 mg/kg).Blood samples were collected from the femoral artery 2 h after CPB for determination of plasma diamine oxidase (DAO),D-lactate and endotoxin levels.Spleen,liver,mesenteric lymph nodes and lung were removed for biochemical analyses.Intestinal tissue ultrastructure was examined by electron microscopy.RESULTS:In the sham-operated groups,high-and low-dose-PHC had no significant impact on the levels of DAO,D-lactate and endotoxin,or the incidence of intestinal bacterial translocation (BT).Serum levels of DAO,D-lactate,endotoxin and the incidence of intestinal BT were significantly increased in the surgical groups,compared with the sham-operated groups (0.543 ± 0.061,5.697 ± 0.272,14.75 ± 2.46,and 0/40 vs 1.038 ± 0.252,9.377 ± 0.769,60.37 ± 5.63,and 30/40,respectively,all P < 0.05).PHC alleviated the biochemical and histopathological changes in a dosedependent manner.Serum levels of DAO,D-lactate,and endotoxin and the incidence of intestinal BT in the high-dose PHC group were significantly lower than in the low-dose PHC group (0.637 ± 0.064,6.972 ± 0.349,29.64 ± 5.49,and 14/40 vs 0.998 ± 0.062,7.835 ± 0.330,38.56 ± 4.28,and 6/40,respectively,all P < 0.05).CONCLUSION:PHC protects the structure and function of the intestinal mucosa from injury after CPB in rats.