传出神经系统药物对家兔血压调节实验方法改进

传出神经系统药物对家兔血压调节实验是医学院校药理学课程的一个重要实验项目。该实验成功率低的主要原因有:麻醉效果不理想、神经血管分离困难、颈动脉插管失败、给药时间把握不准等。笔者改进实验方法,提高实验成功率和教学效果。

植物激素对植物器官脱落的调节实验的改进

以大叶黄杨叶柄为外植体材料，采用含有激素的琼脂块代替注射激素液滴的处理方法，将植物激素对植物器官脱落的影响实验进行了改进．

变风量空调系统运行调节实验的设计

本文以中原工学院楼宇自动化实验室为基础,对变风量空调系统运行调节实验设计进行讨论。通过该实验,可以让学生更好地了解和掌握变风量空调系统运行过程及基本控制原理,对提高学生的专业知识水平和综合素质具有重要作用。

动脉血压调节实验中设计颈动脉窦综合症项目浅谈

动脉血压调节实验的目的是使学生了解神经及体液因素对动脉血压的调节作用。颈动脉窦和主动脉弓压力感受性反射（减压反射）是典型的负反馈调节机制。当动脉血压升高时，刺激颈动脉窦和主动脉弓的压力感受器，冲动分别经窦神经（并入舌咽神经）及迷走神经进人中枢（家兔主动脉弓的传入神经在颈部自成一束，称为减压神经，在颅底减压神经并入迷走神经）。感觉传人使心迷走中枢的紧张性增强，心交感中枢的紧张性降低，从而心迷走神经传出冲动增多而心交感神经传出冲动减少、交感缩血管神经传出冲动减少，结果导致心率减慢、动脉血压下降。

电热设备开闭环系统精确调节方式的研究

电热设备双向晶闸管功调系统常存在零点误差大、谐波含量高、温度闭环调节稳定性差、调整过程长、误差大等缺点。针对不足,对智能无级调节器实践案例和相关文献进行分析,论述了零点精确检测的硬件方案以及实验研究法和逐次自动逼近法两种软件方案的基本原理。实验证明,软硬件方案零点检测误差低于0.5μs,输出稳定、通断点精确、功率连续、谐波含量低、恒温调节有效。该调节方案可有效解决电热功率输出和恒温控制中的不足。

基于PLC的大功率可调节等离子点火控制系统

文章以大功率可调节等离子点火实验平台为工程背景,介绍了以PLC和组态软件为控制核心的大功率可调节煤粉等离子点火控制系统。首先介绍实验平台的主要设备和功能,紧接着叙述了硬件部分组成功能以及软件部分构成和控制逻辑,并且重点介绍了使用PID控制的等离子喷枪功率调节功能和风粉浓度自动给定功能及实现方法,最后概括的介绍了远程监控软件界面及报表存储和打印的功能。

轴线平行度误差对齿根变形弯曲应力的影响研究

为了研究轴线倾斜造成的装配平行度误差对齿轮啮合过程齿根弯曲变形的影响,设计并搭建了一套齿轮轴线可调节的齿轮箱实验台和完整的应变采集分析系统,并进行实验验证。基于调心滚子轴承内外圈的允许偏差,建立不同轴线偏移程度的齿轮组接触有限元模型,并进行动态仿真分析,获得啮合过程中的齿根应变应力分布曲线;通过对实验所需的不同轴线的调节方式的设计,对比了调节前后两轴角度的偏差实际值与理论值,验证了调节装置的可行性;最后,通过应变片采集卡等组成的应变采集系统,测试了不同轴线平行度误差下的齿根应变值,得到了相应的啮合应变应力分布曲线,并与仿真得到的啮合应变应力曲线进行对比,得出轴线平行度误差对齿根危险截面处弯曲变形应力的影响。

Long-term modifications of blood pressure in normotensive and spontane-ously hypertensive rats by gene delivery of rAAV-mediated cytochrome P450 arachidonic acid hydroxylase

Arachidonic acid cytochrome P-450 （CYP） hydroxylase 4A isoforms, including 4A1, 4A2, 4A3 and 4A8 in the rat kidney, catalyze arachidonic acid to produce 19/20-Hydroxyeicosatetraenoic acids （20-HETE）, a biologically active metabolite, which plays an important role in the regulation of blood pressure. However, controversial results have been reported regarding the exact role of 20-HETE on blood pressure. In the present study, we used recombinant adenoassociated viral vector （rAAV） to deliver CYP 4A1 cDNA and antisense 4A1 cDNA into Sprague-Dawley （SD） rats and spontaneously hypertensive rats （SHR）, respectively, to investigate the effects of long-term modifications of blood pressure and the potential for gene therapy of hyperténsion. The mean systolic pressure increased by 14.2±2.5 mm Hg in rAAV.4A 1-treated SD rats and decreased by 13.7±2.2 mm Hg in rAAV.anti4A l-treated SHR rats 5 weeks after the injection compared with controls and these changes in blood pressure were maintained until the experiments ended at 24 weeks. In 4A1 treated animals CYP4A was overexpressed in various tissues, but preferentially in the kidney at both mRNA and protein levels. In anti-4Al-treated SHR, CYP4A mRNA in various tissues was probed, especially in kidneys, but 4A l protein expression was almost completely inhibited. These results suggest that arachidonic acid CYP hydroxylases contribute not only to the maintenance of normal blood pressure but also to the development of hypertension. rAAV-mediated anti4A administration strategy has the potential to be used as targeted gene therapy in human hypertension by blocking expression of CYP 4A in kidneys.

Effects of soy components on blood and liver lipids in rats fed high-cholesterol diets

AIM: To assess the effects of soy protein, isoflavone, and saponin on liver and blood lipid in rats that consumed high-cholesterol diets.METHODS: High-cholesterol diets (1%) with or without soy material were fed to 6-wk-old male Sprague-Dawley rats for 8 wk. Blood lipids, liver lipids, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) levels were measured. The in vitro bile acid-binding ability of soy materials was analyzed.RESULTS: The results of in vitro studies showed that soy protein isolate had a significantly higher bile acid-binding ability (8.4±0.8%) than soy saponin (3.1±0.7%) and isoflavone (1.3±0.4%, P＜0.05). On the other hand, at the end of the experimental period, rats that consumed soy protein diets had lower GOT and GPT levels than rats that consumed casein under high-cholesterol diets.Rats that consumed soy protein also had lower total cholesterol (TC) levels in the liver than those that consumed casein under high-cholesterol diets. Rats that consumed the soy protein diet containing both saponin and isoflavone had lower hepatic TC level than those that consumed the soy protein diet without isoflavone alone.The effect of different types of proteins on triglyceride was not significant.CONCLUSION: Consumption of soy provided benefits to control lipid levels under high-cholesterol dieting conditions in this rat model of hypercholesterolemia. The major component that reduced hepatic TC was not saponin, but possibly isoflavone.

Effect of normothermic liver ischemic preconditioning on the expression of apoptosis-regulating genes C-jun and Bcl-X_L in rats

AIM: To explore the expression of apoptosis-regulatinggenes C-jun and Bcl-XL after normothermic liver ischemic preconditioning and its protective effect on hepatocytes in the rat.METHODS: Wistar rats are randomly divided into sham operation group (S group, n = 10), ischemic reperfusion group (IR group, n = 10) and ischemic preconditioning group (IP group, n = 10). After dissection of the hepatoduodenal ligament in S group, and after 30-min reperfusion in IR group and in IP group, the samples of liver tissue were taken for studying the hepatocellular apoptosis, theexpressions of C-jun mRNA, Bcl-XL mRNA and their proteins, and morphologic changes at 0, 3, 6, 20 h. Meanwhile the venous blood samples were drawn at 3, 6 and 20 h for testing ALT, AST and LDH.RESULTS: The levels of ALT, AST and LDH in IR group and IP group were significantly higher than those in S group. Hepatocellular apoptosis was significantly increased in both IR group and IP group, especially in IR group.Expressions of C-jun mRNA and protein were significantly increased in IR group compared with those in both IP group and S group, but no significant difference between IP group and S group (P＞0.05). Expressions of Bcl-XL mRNA and protein in IR group and S group were not significant (P＞0.05), but were significantly increased in IP group compared with those in both S group and IR group. Patch necrosis of hepatocytes because of severe injury could be seen in IR group microscopically, and the ultrastructural changes were irreversible. Meanwhile in IP group, no hepatocellular necrosis occurred, and the ultrastructural changes were reversible because of mild injury. CONCLUSION: (1) IP can protect the rat liver from normothermic IR injury by modulation of the expressionof apoptosis-regulating genes C-jun and Bcl-XL; (2) IR injury may activate the apoptosis of hepatocytes by increasing the expression of apoptosis-inducing gene C-jun; (3) IP may prohibit the apoptosis of hepatocytes by increasing the expression of apoptosis-inhibitory gene Bcl-XL.

Experimental study of a simple pressure loss coefficient model for multi-hole orifice

A throttling experiment for the multi-hole orifice （MO） using water was conducted based on the conclusion of key parameters affecting the MO throttling performance. Testing MOs and standard orifice plates （ SO ） were designed for the throttling experiment to compare the throttling effect using the equivalent diameter ratio （RED） and diameter ratio （RD ） as key parameters, respectively. Meanwhile, effective metrical conditions were provided for experimental accuracy. The throttling model form was determined according to the theoretical throttling model of SO. Then the unknown parameters involved were identified by experimental data. A good concordance between the modeling computation and experimental results shows a validation of the MO throtting model.

Acoustic Conditioning System Development and Conditioning Experiments on Black Seabreams in the Xiangshan Bay Sea Ranch

Attracting released hatchery-reared fish to designated areas during the growth process is vital to realize the objectives of sea ranching. Based on the bottom artificial reefs and surface kelp culture facilities in the Xiangshan Bay sea ranch, we proposed systematic techniques related to acoustic conditioning of the black seabream(Sparus macrocephalus). Experiments conducted in 12 m × 10 m × 1.6 m ponds on Xixuan Island showed that black seabream was positively sensitive to 500–600 Hz periodic signals. Conditioned responses were apparent after 8 d. Two to three days were required for recovery of the memory of a conditioned response after a 20-day interval. According to the practical application requirements in the open sea, unattended acoustic conditioning equipment was developed. The ranching equipment was used in 12 m × 12 m × 2.5 m cages, and the behavior of black seabream juveniles was successfully guided after 7 days. Of the 16000 released fish, 82.5% of them were conditioned with a flexible grading net. To avoid inducing a stress response, the juveniles were released into the sea ranch in situ from the net cage. The acoustic conditioning equipments were moved into the open sea and the aggregation phenomenon of the released fish was observed when the sound was played. After 6 months of investigation and based on Sr+ marking, only one acoustically conditioned fish was found outside the 3.5-km^2 sea ranch area, thereby reached the goal of guiding activity. The practical effect in the Xiangshan Bay sea ranch showed the validity of the acoustic conditioning system, which may contribute to improve the operation of the sea ranches in the East China Sea.

Experimental analysis on adjusting performance of vapor-liquid two-phase flow controller

The vapor-liquid self-adjusting controller is an innovative automatic regulating valve.In order to ensure adjusted objects run safely and economically,the controller automatically adjusts the liquid flux to keep liquid level at a required level according to physical properties of vapor-liquid two-phase fluid.The adjusting mechanics,the controller’s performance and influencing factors of its stability have been analyzed in this paper.The theoretical analysis and successful applications have demonstrated this controller can keep the liquid level steady with good performance.The actual application in industry has shown that the controller can satisfactorily meet the requirement of industrial production and has wide application areas.

Automatic Voltage Regulator Test of Three Gorges Right Bank Hydropower Station

Based on real-time digital simulations(RTDS),a laboratory environment similar to the real-time operation situation of the Three Gorges Hydropower Station is established.Then,the causes for the power fluctuation of the second generator by errors in the rotor rotating speed calculation are found,and the tuning method of the speed related parameters are given.The damping and reverse tuning characteristics of power system stabilizers(PSSs)in the digital automatic voltage regulator(AVR)are compared and investigated in the frequency range of 0.18-1.1 Hz.The efficiency of the proposed tuning method for ensuring power system stability is verified by RTDS.Finally,field tests show the validity of the laboratory test results.

Effect of Astragalus Polysaccharide on the Cell-mediated Immunity of Traumatic Stress Mice

To investigate the changes of immune functions and the effects of Astragalus polysaccharide (ASP) on the cell-mediated immunity of the traumatic stress model of mouse by amputation, 50 mice were randomly divided into 5 groups for study, in which the group A and B served as the normal control (by injecton of 0.5 ml of saline intra-peritoneally daily), and as the stress control (by intra-peritoneal injecton of 0.5 ml of normal saline into mice after amputation) respectively, to the group C, D and E of mice, 1000 mg/kg (high dose), 300 mg/kg (median dose) and 250 mg/kg (low dose). The CD4 + and CD8 + T cells as well as the expression of the c-fos protein were determined by immunohistochemical techniques, and the expressions of NF-κB mRNA and IL-10 mRNA were assayed by hybridization in situ . The experimental results showed that in comparison with the normal control group of mice (group A), the expression levels of NF-κB mRNA, IL-10 mRNA and the c-fos protein in the tissues of thymus and spleen in the stress controls were significantly elevated and the CD4 + T cells and CD4/CD8 ratio were decreased. However, in comparison with the stress control of mice (group B), the expressions of NF-κB mRNA and IL-10 mRNA were inhibited by ASP, and the CD4 + T cells and CD4/CD8 ratio were increased in groups C, D and E, but the level of c-fos protein was decreased. There was no significant difference in these parameters among group C, D and E. It is concluded that the functions of cell-mediated immunity of mice were disturbed under the stress condition of the traumatic injuries after amputation. And the immune functions can be effectively restored by the use of Astragalus polysaccharide.

Examination for Experimental Verification of Improvement of Power Quality in Distribution System by PCS

In the future, the power quality will decrease by the introduction of a lot of renewable energy sources. The topic of this research is a new method of operation of PCS （power conditioning systems） in the future distribution system. The purpose of this research is development of PCS with a function of improvement of the distribution system. Therefore, the authors propose a method of the power quality improvement of the distribution system by PCS. In addition, the authors construct the control logic to use in PCS The control logic suggests adding harmonic restraint function to conventional control. These were verified by simulation and an experiment. As the results, we confirmed that basic operation of PCS being carried out, harmonics were restrained, and power quality had improved.

Adeno-associated virus mediated delivery of Tregitope 167 ameliorates experimental colitis

AIM:To explore the anti-inflammatory potential of adeno-associated virus-mediated delivery of Tregitope 167 in an experimental colitis model.METHODS:The trinitrobenzene sulfonate(TNBS) model of induced colitis was used in Balb/c mice.Subsequently after intravenous adeno-associated virusmediated regulatory T-cell epitopes(Tregitope) delivery,acute colitis was initiated by intra-rectal administration of 1.5 mg TNBS in 40% ethanol followed by a second treatment with TNBS(0.75 mg in 20% ethanol) 8 d later.Control groups included mice not treated with TNBS(healthy control group) and mice treated by TNBS only(diseased group).At the time of sacrifice colon weight,the disease activity index and histology damage score were determined.Immunohistochemical staining of the colonic tissues was performed to asses the cellular infiltrate and the presence of transcription factor forkhead Box-P3(Foxp3).Thymus,mesenteric lymph nodes,liver and spleen tissue were collected and the corresponding lymphocyte populations were further assessed by flow cytometry analysis for the expression of CD4+ T cell and regulatory T cell associated markers.RESULTS:The Tregitope 167 treated mice gained an average of 4% over their initial body weight at the time of sacrifice.In contrast,the mice treated with TNBS alone(no Tregitope) developed colitis,and lost 4% of their initial body weight at the time of sacrifice(P < 0.01).The body weight increase that had been observed in the mice pre-treated with Tregitope 167 was substantiated by a lower disease activity index and a decreased colon weight as compared to the diseased control group(P < 0.01 and P < 0.001,respectively).Immunohistochemical staining of the colonic tissues for CD4+ showed that inflammatory cell infiltrates were present in TNBS treated mice with or without administration with tregitope 167 and that these cellular infiltrates consisted mainly of CD4+ cells.For both TNBS treated groups CD4+ T cell infiltrates were observed in the sub-epithelial layer and the lamina propria.CD4+ T cell infiltrates were also present in the muscularis mucosa layer of the diseased control mice,but were absent in the Tregitope 167 treated group.Numerous Foxp3 positive cells were detected in the lamina propria and sub-epithelium of the colon sections from mice treated with Tregitope 167.Furthermore,the Foxp3 and glycoprotein A repetitions predominant markers were significantly increased in the CD4+ T lymphocyte population in the thymus of the mice pre-treated with adeno-associated virus serotype 5(cytomegalovirus promoter-Tregitope 167),as cytomegalovirus promoter compared to lymphocyte populations in the thymus of diseased and the healthy control mice(P < 0.05 and P < 0.001,respectively).CONCLUSION:This study identifies adeno-associated virus-mediated delivery of regulatory T-cell epitope 167 as a novel anti-inflammatory approach with the capacity to decrease intestinal inflammation and induce longterm remission in inflammatory bowel disease.

MPPT Control System for PV Generation System with Mismatched Modules

Nowadays, in a household PV （photovoltaic） generation system, it is generally connecting PV modules in series and then output to the power-conditioner. However, when PV modules are mismatched, it will lead to a wrong MPPT （maximum power point tracking） to all modules and a power decreasing of the whole system. Aiming at this problem, this paper presents the idea which improves the MPPT without changing the conventional power-conditioner, by adding a Buck type DC-DC （direct current） converter behind each module. Simulations of PSIM （power simulation） and experiments are taken to prove this theory. The result shows that, by this idea, the generated power of the conventional PV generation system can be greatly increased under the condition of mismatch.

Experimental and Analytical Study of Torsional Vibration under Multiaxial Loading in Time Domain

The torsional vibration of power transmission shaft is a phenomenon whose analytical modeling can be represented by a differential equation of motion proposed by technical literature. The solutions of these equations need coefficients and parameters that, usually, must be experimentally estimated. This work uses a resistive electric SG （strain gage） to dynamically determine strains produced in the shaft due to harmonic oscillatory motion under multiaxial loading. This movement is simulated on a prototype specially developed for this purpose. It comprises a pulley attached to the end of a stepped cantilevered shaft, which is clamped at the opposite end. In this configuration, a cam generates a torque to the system, springs regulate the stiffness and the damping coefficient of the assembly, as well as they can be suitably adjusted to produce an underdamped condition. The main advantage, highlighted in this study, refers to a major simplification. Although the system under study shows multiple degrees of freedom （torsion and bending）, the shape and the positioning of linking SGs with the resistor bridge （Wheatstone Bridge）, allow ＂to evaluate the loading effects independently, as if only one degree of freedom of the system exists at a time domain. Strains graphs for two forms of cyclic torsional oscillation, analytical and experimental, were successfully generated.

On nonparametric change point estimator based on empirical characteristic functions

We propose a nonparametric change point estimator in the distributions of a sequence of independent observations in terms of the test statistics given by Huˇskov′a and Meintanis(2006) that are based on weighted empirical characteristic functions. The weight function ω(t; a) under consideration includes the two weight functions from Huˇskov′a and Meintanis(2006) plus the weight function used by Matteson and James(2014),where a is a tuning parameter. Under the local alternative hypothesis, we establish the consistency, convergence rate, and asymptotic distribution of this change point estimator which is the maxima of a two-side Brownian motion with a drift. Since the performance of the change point estimator depends on a in use, we thus propose an algorithm for choosing an appropriate value of a, denoted by a_s which is also justified. Our simulation study shows that the change point estimate obtained by using a_s has a satisfactory performance. We also apply our method to a real dataset.