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The pathogenesis of alopecia areata, a common autoimmune non-scarring alopecia, remains unclear・ Current studies have shown that the loss of immune privilege of hair follicles due to the up-regulation of MHC molecules and the decrease in immunosuppressive molecules leads to the exposure of self-antigens in the affected area・ This triggers the infiltration of immune cells (such as CD8 + T cells, NK cells, plasmacytoma dendritic cells, and mast cells) around the hair bulb ・ Various immune cells and related cytokines participate in the pathogenesis and development of this disease through diverse signaling pathways・ Due to its complex pathogenesis and diverse clinical manifestations, there are challenges in the diagnosis and treatment in clinic・ This paper aims to provide a comprehensive review on recent advances in understanding the immunological pathogenesis of alopecia areata by focusing on mechanisms underlying immune privilege loss around hair follicles and the interaction between various immune cells in the microenvironment for a deeper understanding of its pathogenesis・ It also seeks to explore new research directions and potential treatment strategies. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Emergency water supply is one of the most important lifeline projects for post-disaster survival support. Multi-stage pump can be the core power source for fluid transportation. A stable and reliable operation is crucial to rescue and support at disaster sites. In actual operation, the unexpected shutdown of emergency water supply multi-stage pumps can cause drastic changes in the performance parameters, such as the impeller rotating speed, flow rate, and pressure. The internal flow field in multi-stage pumps can pose a serious threat to the water supply safety. This study aims to investigate the transient response to the internal flow field during the hydraulic transition of multi-stage pump shutdown. A speed prediction was established to numerically calculate the internal flow field of the stage pump, according to the rotation balance equation of the impeller. The transient effects were analyzed from the dynamic characteristics of the impeller rotating speed, outlet flow rate, torque and the flow structures inside each stage of the impeller during the unexpected shutdown. The results indicate that the multi-stage pump shared four conditions during unplanned shutdown, pumping, braking, reversing and runaway. The rotational speed of the impeller showed a trend of first decreasing in the positive direction, and then increasing in the reverse direction, while finally stabilizing around the runaway speed of -4 210 r/min. The flow rate of the pump showed a trend of first positive decrease followed by a reverse increase, then stable reverse decrease and finally stayed around the runaway flow rate of -14.32 kg/s. The torque showed a trend of positive decrease followed by a positive increase, then stable positive decrease and finally stayed near zero. The continuous changes in the magnitude and direction of flow and speed inside the pump were attributed to the flow separation and backflow inside the impeller channel, accompanied by spatiotemporal evolution, such as the formation, development and fragmentation of vortices. The entropy output value was closely related to the unstable flow structure inside the multi-stage pump, while the loss caused by turbulent dissipation played a dominant role. The turbulent dissipation entropy production accounted for about 65.2% after reaching the runaway condition. Energy loss mainly occurred inside the impeller flow channel. There was a significant loss of the internal flow field in the braking condition. There was the most variation in the pressure fluctuation at the monitoring points in the first stage flow channel of the multi-stage pump. The amplitude of the pressure fluctuation coefficient showed a decreasing trend with the increase of the stage number. The dominant frequency of the pressure pulsation amplitude was positively correlated to the rotating speed of the multi-stage pump, corresponding to the blade passage frequency. The amplitude of dominant pressure pulsation frequencies gradually increased along the direction of fluid flow. There was the most significant change in the first stage flow channel during the unexpected shutdown of the multistage pump, which was accompanied by the most complex flow structure. The frequency characteristics of pressure pulsation can reflect the differential changes in flow instability during unexpected shutdowns. The research results can provide theoretical guidance for the safe and stable operation of emergency water supply systems. [ABSTRACT FROM AUTHOR]

Copyright of Diamond & Abrasives Engineering is the property of Zhengzhou Research Institute for Abrasives & Grinding and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Zhengzhou University: Engineering Science is the property of Editorial Office of Journal of Zhengzhou University: Engineering Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Regional Studies is the property of World Regional Studies Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Management & Technology Discussion is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Science Research & Application is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Water Conservancy & Electric Power Technology & Application is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The unsteady gas-liquid two-phase flow has often posed a great threat to the pump performance, particularly with the increase of inlet gas void fraction during transportation. The traditional two-fluid model cannot consider the variation of bubble diameter and the interaction between bubbles. In this study, a group equilibrium model (Musig model) was proposed to simulate the internal flow in the centrifugal pump with the semi-open impeller under different inlet gas void fractions. The simulation works were then verified by the experimental pump performance and visualization test. Some parameters were obtained, including the pump performance, the bubble distribution in the middle section, and the turbulent kinetic energy distribution under different inlet void fractions at the design flow rate. A proper cause was analyzed for the deterioration of pump performance under a large void fraction, together with the velocity distribution and bubble variation at the tip clearance between blade and pump casing. The results show that the maximum handing ability was 4.6% about the inlet gas void fraction of the model pump at 1000 r/min. When the void fraction was greater than 3%, the Musig model was more accurate to predicate the pump performance, particularly suitable for the evolution of gas-liquid two-phase flow, such as bubble morphology, fragmentation, and polymerization, compared with the Euler-Euler two fluid model. Specifically, the maximum errors of head coefficient and efficiency were 1.6% and 5%, respectively, when the inlet gas void fraction was 4% at a pump design flow rate. Moreover, the predicted bubble distribution and flow pattern were consistent with the visualization experiment. The flow patterns (such as the uniform/polymeric bubble, cavitation, and separated flow) gradually appeared in the impeller and volute channels, with the increase of inlet gas void fraction. There was a mainly uniform distribution of bubble flow inside the channel at a design flow rate when the inlet gas void fraction was less than 1%. The polymeric bubble flow appeared, when the inlet gas void fraction reached 3%. The cavitation flow then dominated, when the inlet gas void fraction reached 4%. Further, the separate flow appeared, when the inlet gas void fraction reached 4.2%, where the flow channel was gradually blocked. The tip clearance was an important parameter to determine the distribution of gas-liquid two-phase flow pattern in the pump, which promoted the bubbles’ transposition from the blade pressure side to the suction side. The maximum velocity was distributed at the gap between the impeller outlet and the volute, where was the place with the most bubble aggregation and distribution patterns of gas-liquid two-phase flow. There were the increasing large-scale vortex and outlet reflux in the impeller channel, with the increase of inlet gas void fraction, leading to the large distribution of turbulent kinetic energy in the high void fraction area, where the unstable flow was intensified inside the pump, and finally leading to the pump idling after the inlet gas void fraction reached 4.6%. This finding can also provide a sound reference for the comprehensive analysis of unsteady flow characteristics in a centrifugal pump. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The vertical inline pump is a centrifugal pump with the elbowed inlet pipe, which has excellent characteristics of simple structure, small volume, easy for installation, and so on. Therefore, it is widely applied in where the constraint is installation space. However, the curved inlet structure also has a negative impact on the inflow conditions before the impeller, which will result in the complex flow phenomenon and decrease of the pump performance. In order to study the features of flow distortion and its impact on the performance and stability of the inline pump, the three-dimensional unsteady Reynolds average Naiver-Stokes equations with the shear stress transfer model were solved by commercial CFD code for the selected pump model in this study. Meanwhile, the Bezier curves were adopted to fit the profiles of the curved inlet pipe and the impeller. Thirty-nine coordinates of the control points of those Bezier curves and the number of the impeller blades were selected as the design variables for the parametric design of the inlet pipe and the impeller. Based on the Latin Hypercube Sampling method, 300 groups of cases were generated in the decision space, and the influence of these design variables on the inflow features and the performance of the inline pump was studied based on Pearson correlation analysis. In order to ensure the reliability of the numerical simulation, a validation experiment on the original pump was carried out. The comparison between the computational results and experimental results showed that the calculation has good accuracy on flow prediction, which could meet the requirements of further study. During the numerical investigation on the original case, a large flow separation area with a pair of secondary flow vortices was found in the inlet passage, which extended along the outer side of the inlet pipe, blocked the flow passage seriously, and deteriorated the outflow conditions of the inlet pipe. Under the nominal and part-load conditions, the main flow features in the inlet pipe were reverse vortex pair and backflow vortex, respectively. The correlation analysis results showed that the performance of the inline pump is significantly related to the blade shape and the number of blades. Under the nominal condition and overload conditions, the increase of the blade angle near the leading edge is beneficial to improve the efficiency and head while the increase of the blade outlet angle has only a positive effect on the lift of the head. Under the part-load conditions, the effect on the performance of the inlet blade angle is significantly reduced and the correlation between the outlet blade angle and the characteristics of the inline pump is prominent. It also reported that the cases with the inlet blade angle of 40°-50°, the outlet blade angle of 20°-40° and longer inlet pipe usually have better performance and stability, which have an average efficiency increase of 5% compared with the original case. The research can provide some reference for the design optimization of inline pumps. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective:To investigate the clinical characteristics and risk factors between different age patients with coronary artery disease (CAD).Methoda:Using retrospective study,480 CAD patients underwent coronary angiogram and interventional therapy in our hospital from 2010 to 2014 were selected,including 320 cases of elder patients(A group) and 160 cases of young and middle age patients (B group).Clinical data,stenosis of coronary artery,disease types and incidence rate of adverse events were analyzed in two groups,compared the laboratory indexes in two groups,and then multiple linear regression analysis was conducted on factors with statistical significance in single factor analysis to explore the risk factors of CAD.Results:(1)The sex ratio and hypertension between the A group and B group showed statistically significance difference (P＜0.05).(2)The incidence of single and triple vessel disease in the A group was significantly higher than that of B group (P＜0.05).The adverse events in the A group were more than those in the B group,including bleeding,arrhythmia and cardiogenic shock(all P＜0.05).(3)The creatinine (Cr),plasma prothrombin time (PT),fibrinogen (FIB) in the A group were significantly higher than B group,but gamma-glutamyltransferase (GGT),tdacylglycerol (TG),homocysteine (Hcy) and platelet count (PLT) were significantly lower than the B group (P＜0.05).(4)Multiple factor regression analysis showed that Hcy and FIB were risk factors of CAD (P＜0.05).Conclusion:There were significant difference between different age patients with CAD in the clinical characteristics,besides the Hey and FIB were the risk factors of CAD.It suggests that the treatment should be different for CAD between the elderly and the young,middle-aged patients with CAD. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To investigate the relationship between serum parathyroid hormone(PTH) level and nutritional status in patients with chronic renal failure(CTo explore the influencing factors on prognosis of patients with cardiopulmonary resuscitation return of spontaneous circulation(ROSC), and to provide reference for clinical disease guidance. Methods: Collected the medical records of 148 patients with sudden cardiac arrest who were underwent cardiopulmonary resuscitation and ROSC in our hospital from January 2012 to January 2015, analyzed the prognosis of patients, and used logistic regression equation to analyze its influencing factors. Results: There were 48 cases(32.43%) of patients with good prognosis,and 100 cases(67.57%) of patients with poor prognosis.Time from sudden cardiac arrest to resuscitation start, time from resuscitation start to ROSC, 72 h body temperature after resuscitation, myoclonus or smoke after resuscitation, D-dimer(D-D) levels after resuscitation, blood p H value after resuscitation, acute physiology and chronic health evaluation(APACHEII) score 3d after resuscitation were risk factors for the prognosis of patients with cardiopulmonary resuscitation and ROSC(P<0.05). Conclusion: There are many factors that affect the prognosis of patients with cardiopulmonary resuscitation and ROSC, when rescuing patients with sudden cardiac arrest, cardiopulmonary resuscitation should be shortened as far as possible,and follow the principle of rescue in 10 min, it may help improving prognosis. [ABSTRACT FROM AUTHOR]

In order to improve the hydraulic design level of centrifugal pump, 4 indicators i.e. noise level at BPF (blade passing frequency), efficiency, head and shaft power were taken as criteria, and the matrix method was firstly used in pump design field to finish the multi-target optimization of a model pump. All the indicators were calculated by the combined CFD/CA (computational fluid dynamics and computational acoustics) method, which was based on Lighthill acoustic analogy. Efficiency, head and shaft power of the pump were obtained from the flow field calculation, and sound pressure level of fluid-borne noise was simulated by the computational acoustics from flow noise source. Vibro-acoustic interaction effect between the fluid and solid wall was not taken into account during the process of fluid-borne noise calculation. The effects of the variation of impeller diameter, blade inlet angle, blade outlet angle and blade outlet width on the 4 indicators were well investigated based on the L9 (34) orthographic experiment. Furthermore, the optimum plan was selected according to the weight of each factor from the simulation. After comparing the test results between the optimized impeller and the original one, it was found that the optimum model satisfied all the standards. The head was 2.5% higher than the original model, the efficiency was 3.8% higher than the original one, the shaft power was 3.3% lower than the original model and the sound pressure level at export was 1.2% lower than the original model at nominal flowrate. It was verified that the matrix optimal method combined with the numerical simulation in pump optimization was feasible. Within the reasonable range, the gap between impeller and volute tongue was no longer the most significant factor for flow-induced noise of the pumps. Moreover, the PIV (particle image velocimetry) method was used to compare the inner flow field of the 2 models and analyze the difference to find out why the optimal impeller could supply a better performance with low noise. Non dimensional velocity related to the same volute inlet radius was used to carry out the comparison. The results showed that there was no obvious "jet-wake" flow structure existing inside the optimization mode, the optimized impeller’s maximum velocity was 6.7% smaller than that of the original prototype pump, and its range of low velocity area was larger than the original pump model. Besides, due to the decreasing of the diameter of impeller, the impeller-tongue interaction effects were also weakened. All of these were the main exact reasons for the phenomenon that the optimal impeller had a lower noise. The key to design an impeller with high efficiency and low noise was to keep a reasonable gap between impeller and tongue (or diffuser), and form a better control on the flow in the impeller channels by better blade shapes so as to weaken the wake pulsation at impeller trailing edge. The research provides the theoretical and technical references for the hydraulic design of the multi-objective optimization, and especially for the new type of non-overload centrifugal pumps with high efficiency and low noise. [ABSTRACT FROM AUTHOR]

目的 观察冠状动脉（冠脉）介入（ PCI）时冠脉内注射负荷量盐酸替罗非班对急性ST段抬高型心肌梗死患者心肌血液灌注和左心室功能的影响。方法 将68例急性ST段抬高型心肌梗死患者随机分为观察组36例和对照组32例，观察组于造影后冠脉内注射盐酸替罗非班（10μg／kg），再行PCI治疗；对照组直接行PCI治疗。PCI术后即刻造影，比较两组溶栓治疗试验（ TIMI）血流分级情况及校正的TIMI帧数，术后7、30、90 d的左室射血分数（ LVEF）、左室舒张末期内径（ LVEDD）、左室收缩末期内径（ LVESD）及术后90 d内并发症。结果观察组35例（97．2％）PCI术后即刻获得TIMI 3级血流，对照组30例（93．8％），两组比较差异无统计学意义（P＝0．598）；观察组校正TIMI帧数（22±2）帧，对照组（26±3）帧，两组比较差异有统计学意义（P＝0．024）。术后7、30、90 d观察组LVEF、LVEDD、LVESD改善情况优于对照组（P均＜0．05）。随访90 d内两组均未发生大出血等并发症。结论 STEMI 患者急诊PCI 术中冠脉内补充注射负荷量盐酸替罗非班，可明显改善心肌梗死再灌注状态，促进左室功能的早期恢复，且不增加出血风险。 [ABSTRACT FROM AUTHOR]