Protective effect and mechanism of lithium chloride pretreatment on myocardial ischemia-reperfusion injury in rats

Objective:To investigate the protective effect and mechanism of lithium chloride pretreatment on myocardial ischemia-reperfusion injury(I-RI)in rats.Methods:A total of 60 SD rats were randomly divided into control group,model group,lithium chloride intervention group and L-arginine methyl ester+lithium chloride intervention group with 15 in each.The I-RI model was established in model group,the Utliium chloride intervention group and L-arginine methyl ester+lithium chloride intervention group by method of seaming along left anterior descending coronary artery myocardial,control group was only opened the chest without seaming,STelevation within 2 min was regarded as modeling success.Model group did not adopted any intervention,lithium chloride intervention group was treated with lithium chloride injection15 mg/kg by jugular venipuncture preoperatively,L-arginine methyl ester+lithium chloride intervention group was treated with intraperitoneal injection of 30mg·kg～(-1)·d～(-1)(L—arginine methyl ester 7 d before the test,and intravenous catheter of 15 mg/kg lithium chloride preoperatively.The hydroxybulyric acid dehydrogenase(HBDH),creatine kinase isoenzyme(CK-MB),superoxide dismutase(SOD),malondialdehyde(MDA)level and nitric oxide synthase(NOS)activites were tested.Each large area of myocardial ischemia tissue was extracted for determination of the MDA content,SOD activity in tissue and serum,and morphological changes of myocardial tissue.Results:SOD activity was highest in lithium chloride intervention group,followed by L-arginine methyl ester+lithium chloride intervention group,control group and model group(P<0.05);SOD activity was highest in L-arginine methyl ester+lithium chloride intervention group intervention group,followed by lithium chloride intervention group,control group and model group(P<0.05).MDA content of myocardial tissue was highest in model group,followed by L-arginine methyl ester+lithium chloride intervention group,the lithium chloride intervention group and control group(P<0.05);serum MDA content was highest in L-arginine methyl ester+lithium chloride intervention group,followed by model group,lithium chloride intervention group and control group(P<0.05).Compared with the control group,serum NOS was significantly higher in model group,lithium chloride intervention group and L-arginine methyl ester+lithium chloride intervention group(P<0.05),there was no statistical difference of serum NOS activity between the three groups(P>0.05);HBDH and CK-MB of plasma were highest in model group,followed by L-arginine methyl ester+lithium chloride intervention group,lithium chloride intervention group and control group(P<0.05).A significantly lighter myocardial damage was observed microscopically in lithium chloride intervention group than that in L-arginine methyl ester+lithium chloride intervention group and model group.Conclusions:lithium chloride pretreatment can significandy reduce the myocardial I-RI,maintain structure and function of myocardial cells,improve the antioxidant ability of myocardial tissue,play an effective role on protecting myocardial I-RI.

A review on the design of ternary logic circuits

A multi-valued logic system is a promising alternative to traditional binary logic because it can reduce the complexity,power consumption, and area of circuit implementation. This article briefly summarizes the development of ternary logic and its advantages in digital logic circuits. The schemes, characteristics, and application of ternary logic circuits based on CMOS, CNTFET, memristor, and other devices and processes are reviewed in this paper, providing some reference for the further research and development of ternary logic circuits.

A simultaneous improvement of both strength and ductility by Sn addition in as-extruded Mg-6Al-4Zn alloy

Commercial wrought Mg alloys normally contain low alloying contents to ensure good formability.In the present work,high-alloyed Mg-6 Al-4 Zn-x Sn(x=1,2 and 3 wt.%,respectively)alloys were fabricated by extrusion.Hereinto,Sn was proven to play an effective contribution to simultaneous improvement in strength and ductility that are traditional trade-off features of synthetic materials.It was found that the average grain size of those alloys decreases significantly from^11 to^4μm as a function of Sn contents increasing from 0 to 3 wt.%,while the amounts of Mg2 Sn and Mg17 Al12 particles continuously increase.More importantly,the addition of Sn leads to the transformation of dominated deformation modes from{1012}extension twinning(1 wt.%)to pyramidal slip(3 wt.%)during tensile tests along the extrusion direction at room temperature.The advantageous combination of ultimate tensile strength(~366 MPa)and elongation(~19%)in Mg-6Al-4Zn-3 Sn alloy is mainly attributed to the strong strain hardening ability induced by the enhanced activity of non-basal slip.This work could provide new opportunities for the development of high-alloyed wrought Mg alloys with promising mechanical properties.

压电半导体杆中的机械场、电场与载流子分布研究（英文）

目的:导出两端自由压电半导体杆在自平衡状态下内部的位移、电场和载流子的解析表达式,研究它们在杆内的分布规律。方法:从三维压电半导体基本方程出发,以n-型半导体为例,导出考虑拉伸变形模式的一维模型方程。由平衡方程和电学高斯方程和平衡态下杆内电流为零的条件得到以电场为未知函数一阶非线性偏微分方程,再利用两端自由的边界条件解出位移、电场和载流子的分布函数。结论:压电半导体杆内位移、载流子和电势关于杆的几何中心对称分布,电场、应变则关于中心呈反对称分布形式;它们在半导体两端部的区域变化比在中心区域的变化剧烈。此外,半导体杆两端部的载流子浓度、位移和电场显著依赖于端部的初始载流子浓度。

Design of a PCB stator coreless axial flux permanent magnet synchronous motor based on a novel topology Halbach array

A novel topology Halbach permanent magnet array is proposed and applied to the design of a printed circuit board(PCB) axial flux permanent magnet(AFPM) motor. Compared with the traditional coreless AFPM motor, this novel topology for a Halbach permanent magnet array PCB stator AFPM motor has larger air-gap magnetic flux density and air-gap flux per pole. The magnetic flux leakage is effectively reduced, and the air-gap magnetic density is close to the sine wave. Results of the finite element analysis and prototype experiments verify the feasibility and effectiveness of the novel Halbach permanent magnet array PCB stator motor. A reference basis and practical value for the design of the PCB AFPM motor are provided.