科创中国

目的:观察质子泵抑制剂( PPI)奥美拉唑对两种不同剂型的麦考酚酸(MPA)药代动力学的影响.方法:两组患者在肾移植术后分别给予不同剂型的MPA[吗替麦考酚酯片(MMF)和麦考酚钠肠溶片(EC-MPS)]抗排斥治疗,均联用环孢素A和激素,均在术后立即给予奥美拉唑预防治疗,持续至术后第7天停用,分别观察术后第3、7、10天MPA的血浆浓度、达峰时间、峰值,其中血浆MPA浓度采用高效液相色谱(HPLC)法测定,分别采集服药前及服药后0.5h、1h、1.5h、2h、3h、4h、6h、8h及12h全血标本,采用WinNonlin 5.2程序,按非房室模型进行药代动力学参数的计算每次MPA浓度的MPA-AUC012h值.比较奥美拉唑对MMF和EC-MPS的达峰时间、峰值浓度和MPA-AUC0.12h值的影响.结果:MMF组在肾移植术后第3、7、10天达峰时间分别为(1.50-±0.71)h、(2.50±1.04)h、(1.25±0.60)h,其中第7天较第3天达峰时间延后,第10天较第7天达峰时间明显提前(P<0.05),峰值浓度分别为(7.69±2.25)μg/ml、(8.95±5.60) μg/ml、(9.87±3.82)μg/ml(P >0.05),MPA-AUC0-12h分别为(38.98±14.63) mg·h/L、(34.59±12.04)mg·h/L、(32.47±10.81) mg·h/L(P >0.05);EC-MPS组在肾移植术后第3、7、10天达峰时间分别为(2.50±0.53)h、(2.56±0.62)、(2.63±0.74)h(P >0.05),峰值浓度分别为(11.56±9.59)μg/ml、( 12.64±8.49) μg/ml、(10.11±9.19)μg/ml (P >0.05),MPA-AUC0.12h分别为(22.76±15.52)mg·h/L、(25.31±10.37)mg·h/L、(16.68±14.77) mg·h/L(P >0.05).MPA-AUC012h两组间比较第3、7、10天P值分别为0.065、0.382、0.05;达峰时间两组间比较第3、7、10天P值分别0.01、0.721、0.002;峰值浓度两组间比较P值分别为0.878、0.328、0.505.结论:奥美拉唑能明显延长MMF达峰时间,可能降低MMF的峰值浓度;但对EC-MPS的药代动力学无影响.在肾移植术后应用MMF作为免疫抑制剂的患者术后应早期的检测MPA的浓度,及时调整MMF的剂量.

The current research of the valveless piezoelectric pump focuses on increasing the flow rate and pressure differential. Compared with the valve piezoelectric pump, the valveless one has excellent performances in simple structure, low cost, and easy miniaturization. So, their important development trend is the mitigation of their weakness, and the multi-function integration. The flow in a spiral tube element is sensitive to the element attitude caused by the Coriolis force, and that a valveless piezoelectric pump is designed by applying this phenomenon. The pump has gyroscopic effect, and has both the actuator function of fluid transfer and the sensor function, which can obtain the angular velocity when its attitude changes. First, the present paper analyzes the flow characteristics in the tube, obtains the calculation formula for the pump flow, and identifies the relationship between pump attitude and flow, which clarifies the impact of flow and driving voltage, frequency, spiral line type and element attitude, and verifies the gyroscopic effect of the pump. Then, the finite element simulation is used to verify the theory. Finally, a pump is fabricated for experimental testing of the relationship between pump attitude and pressure differential. Experimental results show that when Archimedes spiral θ=4π is selected for the tube design, and the rotation speed of the plate is 70 r/min, the pressure differential is 88.2 Pa, which is 1.5 times that of 0 r/min rotation speed. The spiral-tube-type valveless piezoelectric pump proposed can turn the element attitude into a form of pressure output, which is important for the multi-function integration of the valveless piezoelectric pump and for the development of civil gyroscope in the future.

Cavitation of centrifugal blood pump is a serious problem accompany with the blocking failure of short inlet cannula.However,hardly any work has been seen in published literature on this complex cavitation phenomenon caused by the coupling effect of inlet cannula blocking and pumps suction.Even for cavitation studies on ordinary centrifugal pumps,similar researches on this issue are rare.In this paper,the roles of throttling,rotation speed and fluid viscosity on bubble inception and intensity in a centrifugal blood pump are studied,on the basis of experimental observations.An adjustable throttle valve installed just upstream blood pump inlet is used to simulate the throttling effect of the narrowed inlet cannula.The rotation speed is adjusted from 2 600 r/min to 3 200 r/min.Glycerin water solutions are used to investigate the influences of kinetic viscosity.Bubbles are recorded with a high-speed video camera.Direct observation shows that different from cavitation in industrial centrifugal pumps,gas nuclei appears at the nearby of vane leading edges while throttling is light,then moves upstream to the joint position of inlet pipe and pump with the closing of the valve.It's found that the critical inlet pressure,obtained when bubbles are first observed,decreases linearly with viscosity and the slope is independent with rotation speeds;the critical inlet pressure and the inlet extreme pressure which is obtained when the throttle valve is nearly closed,fall linearly with rotation speed respectively and the relative pressure between them is independent with rotation speed and fluid viscosity.This paper studies experimentally on cavitation in centrifugal blood pump that caused by the failure of assembled short inlet cannula,which may beneficial the design of centrifugal blood pump with inlet cannula.

The existing research on improving the hydraulic performance of centrifugal pumps mainly focuses on the design method and the parameter optimization.The traditional design method for centrifugal impellers relies more on experience of engineers that typically only satisfies the continuity equation of the fluid.In this study,on the basis of the direct and inverse iteration design method which simultaneously solves the continuity and motion equations of the fluid and shapes the blade geometry by controlling the wrap angle,three centrifugal pump impellers are designed by altering blade wrap angles while keeping other parameters constant.The three-dimensional flow fields in three centrifugal pumps are numerically simulated,and the simulation results illustrate that the blade with larger wrap angle has more powerful control ability on the flow pattern in impeller.The three pumps have nearly the same pressure distributions at the small flow rate,but the pressure gradient increase in the pump with the largest wrap angle is smoother than the other two pumps at the design and large flow rates.The pump head and efficiency are also influenced by the blade wrap angle.The highest head and efficiency are also observed for the largest angle.An experiment rig is designed and built to test the performance of the pump with the largest wrap angle.The test results show that the wide space of its efficiency area and the stability of its operation ensure the excellent performance of the design method and verify the numerical analysis.The analysis on influence of the blade wrap angle for centrifugal pump performance in this paper can be beneficial to the optimization design of the centrifugal pump.

Currently, relatively large errors are found in numerical results in some low-specific-speed centrifugal pumps with unshrouded impeller because the effect of clearances and holes are not accurately modeled. Establishing an accurate analytical model to improve performance prediction accuracy is therefore necessary. In this paper, a three-dimensional numerical simulation is conducted to predict the performance of a low-specific-speed centrifugal pump, and the modeling, numerical scheme, and turbulent selection methods are discussed. The pump performance is tested in a model pump test bench, and flow rate, head, power and efficiency of the pump are obtained. The effect of taking into consideration the back-out vane passage, clearance, and balance holes is analyzed by comparing it with experimental results, and the performance prediction methods are validated by experiments. The analysis results show that the pump performance can be accurately predicted by the improved method. Ignoring the back-out vane passage in the calculation model of unshrouded impeller is found to generate better numerical results. Further, the calculation model with the clearances and balance holes can obviously enhance the numerical accuracy. The application of disconnect interface can reduce meshing difficulty but increase the calculation error at the off-design operating point at the same time. Compared with the standard k–ε, renormalization group k–ε, and Spalart–Allmars models, the Realizable k–ε model demonstrates the fastest convergent speed and the highest precision for the unshrouded impeller flow simulation. The proposed modeling and numerical simulation methods can improve the performance prediction accuracy of the low-specific-speed centrifugal pumps, and the modeling method is especially suitable for the centrifugal pump with unshrouded impeller.

Microchannel heat sink with high heat transfer coefficients has been extensively investigated due to its wide application prospective in electronic cooling.However,this cooling system requires a separate pump to drive the fluid transfer,which is uneasy to minimize and reduces their reliability and applicability of the whole system.In order to avoid these problems,valveless piezoelectric pump with fractal-like Y-shape branching tubes is proposed.Fractal-like Y-shape branching tube used in microchannel heat sinks is exploited as no-moving-part valve of the valveless piezoelectric pump.In order to obtain flow characteristics of the pump,the relationship between tube structure and flow rate of the pump is studied.Specifically,the flow resistances of fractal-like Y-shape branching tubes and flow rate of the pump are analyzed by using fractal theory.Then,finite element software is employed to simulate the flow field of the tube,and the relationships between pressure drop and flow rate along merging and dividing flows are obtained.Finally,valveless piezoelectric pumps with fractal-like Y-shape branching tubes with different fractal dimensions of diameter distribution are fabricated,and flow rate experiment is conducted.The experimental results show that the flow rate of the pump increases with the rise of fractal dimension of the tube diameter.When fractal dimension is 3,the maximum flow rate of the valveless pump is 29.16 mL/min under 100 V peak to peak(13 Hz)power supply,which reveals the relationship between flow rate and fractal dimensions of tube diameter distribution.This paper investigates the flow characteristics of valveless piezoelectric pump with fractal-like Y-shape branching tubes,which provides certain references for valveless piezoelectric pump with fractal-like Y-shape branching tubes in application on electronic chip cooling.

外质体( Exosomes)足起源于多泡体的微小囊泡,由细胞内吞途径中的多泡体外膜和细胞膜融合后释放到胞外环境或体液中.Exosomes含有多种蛋白、mRNAs、microRNAs、信号分子等,能够反映来源细胞的生物学状态,因而可能成为潜在的生物学标志物.目前,exosomes的研究大多集中在免疫学和肿瘤学,并已经成为一种免疫治疗的新手段,应用于肿瘤治疗和免疫耐受等方面.近年人们才关注exosomes与肾脏疾病的关系,研究表明几乎所有肾脏上皮细胞包括肾小球足细胞、肾小管上皮细胞、尿道上皮细胞均可分泌exosomes,因此尿液来源的exosomes可能成为寻找肾脏疾病早期诊断的标志物.本文着重从exosomes的生物学特性及其在肾脏疾病诊断和治疗的研究进行综述.

The 3D inverse design method,which methodology is far superior to the conventional design method that based on geometrical description,is gradually applied in pump blade design.However,no complete description about the method is outlined.Also,there are no general rules available to set the two important input parameters,blade loading distribution and stacking condition.In this sense,the basic theory and the mechanism why the design method can suppress the formation of secondary flow are summarized.And also,several typical pump design cases with different specific speeds ranging from centrifugal pump to axial pump are surveyed.The results indicates that,for centrifugal pump and mixed pump or turbine,the ratio of blade loading on the hub to that on the shroud is more than unit in the fore part of the blade,whereas in the aft part,the ratio is decreased to satisfy the same wrap angle for hub and shroud.And the choice of blade loading type depends on the balancing of efficiency and cavitation.If the cavitation is more weighted,the better choice is aft-loaded,otherwise,the fore-loaded or mid-loaded is preferable to improve the efficiency.The stacking condition,which is an auxiliary to suppress the secondary flow,can have great effect on the jet-wake outflow and the operation range for pump.Ultimately,how to link the design method to modern optimization techniques is illustrated.With the know-how design methodology and the know-how systematic optimization approach,the application of optimization design is promising for engineering.This paper summarizes the 3D inverse design method systematically.

目的 观察伤椎置钉并椎体内植骨内固定术在胸腰椎骨折治疗中的应用效果.方法 至少一侧椎弓根完整的胸腰椎骨折26例,予伤椎撬拨复位置钉、椎体内植骨、椎弓根内固定,据胸腰段正侧位片比较术前、术后即刻、术后6个月的椎体高度及Cobb's角,并评估脊髓神经功能和融合情况.结果 术后随访7~28个月.患者术后即刻伤椎椎体前缘高度占正常高度百分比及Cobb's角优于术前(P均<0.05);伤椎外形恢复满意;按ASIA脊髓神经功能分级,伴神经损伤者15例中,A级1例无恢复,余均改善1~3级(P均<0.05),内固定无失效,植骨皆融合.结论 伤椎置钉并椎体内植骨内固定术治疗胸腰椎骨折可重建椎体结构,增强脊柱稳定,近期疗效较好.

浙江是原始瓷的重要产地,德清火烧山窑址是目前已知的唯一一处西周晚期至春秋晚期的原始瓷窑址,也是目前已发掘最早的纯烧原始瓷的窑址,对于探索中国早期青瓷的烧造技术具有极其重要的意义.选取早期(西周晚期到春秋初期)样品18个,中后期(春秋中期后段)样品15个,晚期(春秋晚期后段)样品17个,进行质子激发X射线荧光(Proton Induced X-ray Emission,PIXE)分析.因子分析用来研究这些不同时期烧造的原始瓷原料来源和相互关系.结果表明,晚期产品所用胎料、釉料与早期产品不同,与中后期产品相同.