梓醇对脑缺血后神经血管单元构筑的影响

目的结合神经行为学评价,研究地黄梓醇对局灶性脑缺血后神经血管单元构筑的影响。方法 SD大鼠18只,随机分为假手术组、模型组、梓醇组,每组6只。采用开颅电凝法制备局灶性脑缺血模型,造模成功后6h予梓醇进行干预(5 mg·kg-1,ip,qd×7d)。术后1、4、7、14 d采用平衡木漏脚率及肢体不对称应用实验进行行为学评分。末次评分后麻醉,灌注明胶墨汁显示血管,取脑组织切片,行神经胶质酸性蛋白(glial fibrillary acidic protein,GFAP)免疫组织化学和尼氏染色分别显示星形胶质细胞和神经元。结果 (1)术后1d与假手术组相比,模型组大鼠各时点平衡木行走足滑落次数明显增加,肢体不对称使用率为63.3%(P<0.01);术后4 d,梓醇组大鼠肢体不对称使用率下降为51.7%,与模型组58.3%比较差异有显著性(P<0.05),术后7、14 d,大鼠的健侧与患侧应用次数差值缩小,肢体不对称使用率分别为31.7%和13.3%,与模型组58.3%和53.3%比较差异有显著性(P<0.01),但均未恢复至假手术组水平。(2)脑缺血后14 d,与假手术组比较,模型组微血管稀疏,变短,丢失42.4%(P<0.01),神经元数目减少66.5%(P<0.01)、胞体固缩、尼氏小体淡染,数目减少,星形胶质细胞数目增多2.3倍(P<0.01)、胞体肥大、分支增多增粗;与模型组相比,梓醇组微血管分布密集(P<0.01),神经元数目增多29.3%(P<0.05),反应性星形胶质细胞减少20.2%(P<0.05),胞体体积较小,接近于正常、分支数目不如模型组多。结论梓醇对局灶性脑缺血后引起的神经血管单元病变有明显的保护作用,且能促进脑缺血后神经功能的恢复。

Theoretical and experimental investigation on nonlinear interaction among wave groups

Wave group is important in ocean wave theory and applications. In the past, nonlinear interaction among wave groups has been studied on the basis of the nonlinear Sehrrdinger equation. Using this theoretical approach, we found that the nonlinear interaction among wave groups causes asymmetry in the shape of the wave envelope （steeper in the front of the curve of the envelope）. An important consequence of this asymmetry is that the highest wave in a wave group appears one individual wave length ahead of the center of the wave group. Further results show that the degree of envelope asymmetry increases with increasing spectral width and the wave steepness. This theoretical analysis has been supplemented by a systematic experimental study of wind waves. Laboratory and some open sea wave data were analyzed. The results show that the shape of the wind wave envelope of wind waves has the same asymmetry predicted by the theoretical approach. The observed degree of deformation of the envelope also increases with increasing spectral width and the wave steepness as predicted by theory. These conclusions have important ramifications for practical applications of ocean wave theory.

Theory and experimental verification of valveless piezoelectric pump with rotatable unsymmetrical slopes

A valveless piezoelectric pump with rotatable unsymmetrical slopes is developed in this research.It has the following features:The pump integrates driving and transporting,and it can mix different fluids while transporting them.In this paper,firstly,the design of the valveless piezoelectric pump with rotatable unsymmetrical slopes was proposed,and the single-direction flow principle was explained.Then,the fluid mechanics model of the valveless piezoelectric pump with rotatable unsymmetrical slopes was established.Meanwhile,the numerical simulation of the pump was performed.Finally,the experiments on relationship between the rotation angles of the slope and the flow rates were conducted.The experimental results showed that the maximum flow was 32.32 mL min 1.The maximum relative error between the theoretical results and the experimental ones was 14.59%.For the relationship between rotation angles and flow ratio of two inlets,the relative error between the experimental and theoretical maxima was 3.75%.Thus,the experiments proved the feasibility of the pump design and verified the theory.

Projected total energy surface description for axial shape asymmetry in ^(172)W

The projected total energy surface(PTES)approach has been developed based on the triaxial projected shell model(TPSM)hybridized with the macroscopic–microscopic method.The total energy of an atomic nucleus is decomposed into macroscopic,microscopic and rotational terms.The macroscopic and microscopic components are described with the liquid drop model and Strutinsky method,respectively,and the rotational energy is given by the TPSM,the term beyond the mean field.To test theory,the PTES calculations have been carried out for the yrast states of the well deformed rare earth nucleus172W,and the theoretical results are in good agreement with the experimental data.By using the equilibrium quardrupole deformations(ε2andγ)determined by the PTES,the calculation of the transition quardrupole moment(Qt)in function of spin also reproduces the experimental data.A comparison between the PTES and TRS methods has been made for theoretical and application uses.

PIV Measurements of Coolant Flow Field in a Diesel Engine Cylinder Head

This paper presents experimental measurements of coolant flow field in the water jacket of a diesel engine cylinder head. The test was conducted at three different flow rates using a 2-D PIV system. Appropriate tracing particles were selected and delivery device was designed and manufactured before the test. The flow parameters, such as velocity, vorticity and turbulence, were used to analyze the flow field. The effects of vortex which was located between the intake valve and the exhaust valve were discussed. The experimental results showed an asymmetric distribution of velocity in the water jacket. This led to an asymmetric thermal distribution, which would shorten the service life of the cylinder head. The structure optimization to the water jacket of cylinder head was proposed in this paper. The experimental system, especially the 2-D PIV system, is a great help to study the coolant flow structure and analyze cooling mechanism in the diesel engine cylinder head.

Two Higgs Doublet Model Ⅲ and Double-Lepton Polarization Asymmetries in Λ_b →Λμ^+μ^- Decays

Using the form factors calculated both in lattice QCD and HQET, we analyze the branching ratio, doublelepton polarization asymmetries and averaged double-lepton polarization asymmetries of Λ_b →Λμ^+μ^- decay in the2 HDM Ⅲ, respectively. Combining the experimental constrains on the 2HDM Ⅲ parameters, we take two set of representative parameter spaces in our calculations. For the branching ratio of Λ+b →Λμμ-decay, considering the uncertainties of the form factors and input parameters, we find the results of both SM and 2HDM Ⅲ can satisfy the current experimental data in the framework of lattice QCD, but not in HQET. Then we calculate the double-lepton polarization asymmetries Pij and their averaged values Pij, we find the double-lepton polarization asymmetries PLT,PNN, and PTT are sensitive to the 2HDM Ⅲ. However, PLN, PNL, PNT, and PTN show the opposite results. The contribution of the 2HDM Ⅲ to their averaged values have similar results.

Branching fractions and direct C P asymmetries of ■_s →K^0h^+h′^-(h(′)=K,π) decays

Motivated by the recent LHCb collaboration measurements of charmless three-body decays of Bs-0 meson, we calculate the branching fractions of Bs→K0h＋h＇-（h（＇）=K,π）decay modes using the factorization approach.Both the resonant and nonresonant contributions are studied in detail. For the decays Bs→K0h＋h＇-（h（＇）=K,π） and Bs→K0h＋h＇-（h（＇）=K,π）our resultsagree well with experimental data, and the former is dominated by the K＊, while the latter one is dominated by the nonresonant con-tribution. Considering the flavor S U（3） symmetry violation, the sum of branching fractions of Bs→K0h＋h＇-（h（＇）=K,π）could accommodate the data well too. It should be noted that both branching fractions are sensitive to the scalar density （Kπ｜sq｜0））. Furthermore, the resonant contributions are dominated by the scalar K;（1430）. We hope that these branching fractions could be measured individually in the experiments so as to test the factorization approach and the flavor S U（3） asymmetry. Moreover, the direct CP asymmetries of these decays are also investigated, which could be measured in the running LHCb experiment and Super-b factory in the future.