In order to improve the in vitro fertilization rate of bovine, the effects of different sperm capacitation methods on fertilization were investigated. Total two treatments were designed： two-time centrifugation （C）...In order to improve the in vitro fertilization rate of bovine, the effects of different sperm capacitation methods on fertilization were investigated. Total two treatments were designed： two-time centrifugation （C）, and one-time centrifugation and swim-up method （CS）. The results showed that the cleavage rate in the C treatment group was （75.6±4.5）%, which showed no difference compared with that （（76.4±1.9）%） in the CS treatment group （P〉0.05）; there was also no significant dif- ference in blastocyst rate between the two treatment groups （（35.7±4.1）% vs. （36.3± 2.7）%, P〉0.05）. However, the CS treatment significantly saved the capacitation time in vitro.展开更多
The cardiac and vascular effect of ethanolamine nitrate ester ferulate (ENF) wasinvestigated on isolated working guinea pig heart (IWH) and rat aortic ring. The coronary blood flowwas remarkably increased while the c...The cardiac and vascular effect of ethanolamine nitrate ester ferulate (ENF) wasinvestigated on isolated working guinea pig heart (IWH) and rat aortic ring. The coronary blood flowwas remarkably increased while the cardiac functions of IWH were not significantly altered by ENFranging from 10-8 to 10-4 mol/L. The percentages of vasorelaxation of ENF t 10 μmol/L) and nicoran-dil (NIC, 10 μmol/L) on K+ (80 mmol/L)-induced contraction in aortic rings were 72 ± 8% and17±8%, respectively. The relaxation effects of ENF and NIC on phenylephrine (PE, 5 μmol/L) in-duced contraction were in a dose-dependent manner. When vessel segments were exposed to PE withmethylene blue (MB, 10 μmol/L) or with glibenclamide (GLI, 10 pmol/L), the percentages of relaxa-tion of ENF (10 μmol/L) and NIC ( 1 0 μmol/L) were 4 1 ±11 % and 49±7% or 76± 14% and the 33±9%,respectively. The results suggested that ENF improved coronary circulation and the vasodilation of ENF was mediated bv nitrate-like action.展开更多
The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce...The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce the aerodynamic noise generated by the centrifugal fan. The flow field and the sound field on the whole centrifugal fan configuration have been carried out using the computational fluid dynamics. Simulation results show that the sound pressure level near the outlet of the centrifugal fan is too high. Based on the relationship between flow characteristics and the aerodynamic noise, four parameters of the centrifugal fan, i.e., impeller blade＇s outlet angle 0, volute tongue＇s gap t, collector inclination angle fl, and rotating speed n, were selected as design variables and optimized using response surface methodology. While keeping the function of flow rate unchanged, the peak noise level is reduced by 8 dB or 10.8%. The noise level is satisfactorily reduced.展开更多
Conventional model tests and centrifuge tests are frequently used to investigate seepage erosion. However, the centrifugal test method may not be efficient according to the results of hydraulic conductivity tests and ...Conventional model tests and centrifuge tests are frequently used to investigate seepage erosion. However, the centrifugal test method may not be efficient according to the results of hydraulic conductivity tests and piping erosion tests. The reason why seepage deformation in model tests may deviate from similarity was first discussed in this work. Then, the similarity criterion for seepage deformation in porous media was improved based on the extended Darcy-Brinkman-Forchheimer equation. Finally, the coupled particle flow code–computational fluid dynamics(PFC-CFD) model at the mesoscopic level was proposed to verify the derived similarity criterion. The proposed model maximizes its potential to simulate seepage erosion via the discrete element method and satisfy the similarity criterion by adjusting particle size. The numerical simulations achieved identical results with the prototype, thus indicating that the PFC-CFD model that satisfies the improved similarity criterion can accurately reproduce the processes of seepage erosion at the mesoscopic level.展开更多
A SLon full-scale continuous centrifugal concentrator was used to reconcentrate hematite from a high gradient magnetic separation concentrate to study the effect of impact angle, concentrate mass and drum rotation spe...A SLon full-scale continuous centrifugal concentrator was used to reconcentrate hematite from a high gradient magnetic separation concentrate to study the effect of impact angle, concentrate mass and drum rotation speed on the impact energy of turbulent water sprays for continuous centrifugal concentration, under conditions of feed volume flow rate around 9 m3/h, feed solid concentration of 25%-35% and reciprocating velocity of water sprays at 0.05 m/s. The results indicate that a minimal critical impact energy is required in the water sprays for achieving continuous concentration of the concentrator; an unfitted impact angle reduces the impact efficiency, and the highest impact efficiency of 0.6416 is found at the mpact angle of 60°; the increase in concentrate mass leads to an increase in impact energy, and the highest impact efficiency is maintained when the concentrate mass varies in the range of 0.44-0.59 kg/s; when the concentrate mass and the pressure of water sprays are kept at around 0.45 kg/s and in the range of 0.4-0.6 MPa respectively, the impact energy increases proportionally with the increase of drum rotation speed.展开更多
Different cell populations from bone marrow are used in various clinical trials for cardiac diseases during last decade. Four clinical studies are on going in our institution and enrol patients with cardiac diseases, ...Different cell populations from bone marrow are used in various clinical trials for cardiac diseases during last decade. Four clinical studies are on going in our institution and enrol patients with cardiac diseases, coronary disease and type 2 diabetes, patients with osteoarthritis. Density gradient is used to separate bone marrow mononuclear cells. Cell processing looses are significant. To find out critical control points we analysed processing process and differences in cell yields between operators performing cell extraction. Bone marrow mononuclear cells were isolated using Ficoll density gradient centrifugation. Cells were counted using flow cytometry for mononuclear cell total counts, CD34＋ population count and viability analysis. The patients who underwent bone marrow aspiration followed by cell isolation received cell suspension for transplantation. Two cells processing for separate patients were performed at once. Same standard operation procedures were applied. Processing looses between operators performing cell extraction were analysed. Bone marrow samples from eight patients were processed. Mononuclear cells were extracted. Operator performances were compared. Operator A average bone marrow mononuclear cell yield in starting material was 9,97 ± 9,98 %, CD34＋ population yield 75,46±79,67%. Operator B average bone marrow mononuclear cell yield in starting material was 24,68 ± 14,8 %, CD34＋ population yield 70,42 ±44.84%. Operator A average cell viability in starting material was 45,24 ± 9,55%, after cell processing 42,96 ± 23,66 %. Operator B average cell viability in starting material was 49,85 ± 5,48%, after cell processing 69,52 ± 6,65 %.展开更多
基金Supported by Earmarked Fund for China Agriculture(Beef and Yak)Research System(NYCYTX-38)Key Agriculture Research and Development Program of Qiqihar(NYGG-201524)~~
文摘In order to improve the in vitro fertilization rate of bovine, the effects of different sperm capacitation methods on fertilization were investigated. Total two treatments were designed： two-time centrifugation （C）, and one-time centrifugation and swim-up method （CS）. The results showed that the cleavage rate in the C treatment group was （75.6±4.5）%, which showed no difference compared with that （（76.4±1.9）%） in the CS treatment group （P〉0.05）; there was also no significant dif- ference in blastocyst rate between the two treatment groups （（35.7±4.1）% vs. （36.3± 2.7）%, P〉0.05）. However, the CS treatment significantly saved the capacitation time in vitro.
文摘The cardiac and vascular effect of ethanolamine nitrate ester ferulate (ENF) wasinvestigated on isolated working guinea pig heart (IWH) and rat aortic ring. The coronary blood flowwas remarkably increased while the cardiac functions of IWH were not significantly altered by ENFranging from 10-8 to 10-4 mol/L. The percentages of vasorelaxation of ENF t 10 μmol/L) and nicoran-dil (NIC, 10 μmol/L) on K+ (80 mmol/L)-induced contraction in aortic rings were 72 ± 8% and17±8%, respectively. The relaxation effects of ENF and NIC on phenylephrine (PE, 5 μmol/L) in-duced contraction were in a dose-dependent manner. When vessel segments were exposed to PE withmethylene blue (MB, 10 μmol/L) or with glibenclamide (GLI, 10 pmol/L), the percentages of relaxa-tion of ENF (10 μmol/L) and NIC ( 1 0 μmol/L) were 4 1 ±11 % and 49±7% or 76± 14% and the 33±9%,respectively. The results suggested that ENF improved coronary circulation and the vasodilation of ENF was mediated bv nitrate-like action.
基金Project(50975083) supported by the National Natural Science Foundation of ChinaProject(61075001) supported by China State Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyProject(201-IV-068) supported by the Fundamental Research Funds for the Central Universities,China
文摘The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce the aerodynamic noise generated by the centrifugal fan. The flow field and the sound field on the whole centrifugal fan configuration have been carried out using the computational fluid dynamics. Simulation results show that the sound pressure level near the outlet of the centrifugal fan is too high. Based on the relationship between flow characteristics and the aerodynamic noise, four parameters of the centrifugal fan, i.e., impeller blade＇s outlet angle 0, volute tongue＇s gap t, collector inclination angle fl, and rotating speed n, were selected as design variables and optimized using response surface methodology. While keeping the function of flow rate unchanged, the peak noise level is reduced by 8 dB or 10.8%. The noise level is satisfactorily reduced.
基金Project(51309086)supported by the National Natural Science Foundation of ChinaProject(20110094120002)supported by the Ministry Education Foundation of ChinaProjects(2014B04914,2011B07214)supported by the Fundamental Research Funds for the Central Universities,China
文摘Conventional model tests and centrifuge tests are frequently used to investigate seepage erosion. However, the centrifugal test method may not be efficient according to the results of hydraulic conductivity tests and piping erosion tests. The reason why seepage deformation in model tests may deviate from similarity was first discussed in this work. Then, the similarity criterion for seepage deformation in porous media was improved based on the extended Darcy-Brinkman-Forchheimer equation. Finally, the coupled particle flow code–computational fluid dynamics(PFC-CFD) model at the mesoscopic level was proposed to verify the derived similarity criterion. The proposed model maximizes its potential to simulate seepage erosion via the discrete element method and satisfy the similarity criterion by adjusting particle size. The numerical simulations achieved identical results with the prototype, thus indicating that the PFC-CFD model that satisfies the improved similarity criterion can accurately reproduce the processes of seepage erosion at the mesoscopic level.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 50638020)
文摘A SLon full-scale continuous centrifugal concentrator was used to reconcentrate hematite from a high gradient magnetic separation concentrate to study the effect of impact angle, concentrate mass and drum rotation speed on the impact energy of turbulent water sprays for continuous centrifugal concentration, under conditions of feed volume flow rate around 9 m3/h, feed solid concentration of 25%-35% and reciprocating velocity of water sprays at 0.05 m/s. The results indicate that a minimal critical impact energy is required in the water sprays for achieving continuous concentration of the concentrator; an unfitted impact angle reduces the impact efficiency, and the highest impact efficiency of 0.6416 is found at the mpact angle of 60°; the increase in concentrate mass leads to an increase in impact energy, and the highest impact efficiency is maintained when the concentrate mass varies in the range of 0.44-0.59 kg/s; when the concentrate mass and the pressure of water sprays are kept at around 0.45 kg/s and in the range of 0.4-0.6 MPa respectively, the impact energy increases proportionally with the increase of drum rotation speed.
文摘Different cell populations from bone marrow are used in various clinical trials for cardiac diseases during last decade. Four clinical studies are on going in our institution and enrol patients with cardiac diseases, coronary disease and type 2 diabetes, patients with osteoarthritis. Density gradient is used to separate bone marrow mononuclear cells. Cell processing looses are significant. To find out critical control points we analysed processing process and differences in cell yields between operators performing cell extraction. Bone marrow mononuclear cells were isolated using Ficoll density gradient centrifugation. Cells were counted using flow cytometry for mononuclear cell total counts, CD34＋ population count and viability analysis. The patients who underwent bone marrow aspiration followed by cell isolation received cell suspension for transplantation. Two cells processing for separate patients were performed at once. Same standard operation procedures were applied. Processing looses between operators performing cell extraction were analysed. Bone marrow samples from eight patients were processed. Mononuclear cells were extracted. Operator performances were compared. Operator A average bone marrow mononuclear cell yield in starting material was 9,97 ± 9,98 %, CD34＋ population yield 75,46±79,67%. Operator B average bone marrow mononuclear cell yield in starting material was 24,68 ± 14,8 %, CD34＋ population yield 70,42 ±44.84%. Operator A average cell viability in starting material was 45,24 ± 9,55%, after cell processing 42,96 ± 23,66 %. Operator B average cell viability in starting material was 49,85 ± 5,48%, after cell processing 69,52 ± 6,65 %.
