Establishment of a Parkinson’s disease model in rats via striatal one-site double injection Feasibility observation

BACKGROUND： To date, many 6-hydroxydopamine （6-OHDA）-lesioned rat models have been established by injecting 6-OHDA into two or more sites in the substantia nigra pars compacta, striatum or median forebrain bundle. The success rate of models established by this method is satisfactory, but it can raise the death rate, and is elaborate and tedious to perform. OBJECTIVE： To observe the difference between injections of 6-OHDA into the striatum from one site and two sites, and to explore the feasibility of establishing Parkinson＇s disease rat models via striatal one-site double injection. DESIGN, TIME AND SETTING： A randomized, controlled animal experiment based on a modeling comparison was performed at the Pharmacology Laboratory of Traditional Chinese Medicine, Academy of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine between August 2005 and April 2006. MATERIALS： A total of 46 male Wistar rats were purchased from Beijing Weitong Lihua Experimental Animal Technical Co., Ltd., China. 6-OHDA hydrogen bromide was sourced from Sigma Co., Ltd., USA. METHODS： All 46 rats were randomized to three groups： one-site injection （n = 18）, two-site injection （n = 18）, and control （n = 10）. Lesions in rat brains were established by infusing 5 μg 6-OHDA into the striatum at the following coordinates： anteroposterior （AP） 1.0 mm, mediolateral （ML） 2.7 mm, dorsoventral （DV）-5.2 or-6.0 mm for the one-site injection group, and AP 1.0 mm, ML 2.5 mm, DV -4.5 mm/AP-0.4 mm, ML 3.5 mm, DV-4.5 mm for the two-site injection group, respectively. Rats in the control group were injected with the same volume of 0.01% ascorbic acid as above. MAIN OUTCOME MEASURES： Tyrosine hydroxylase-positive neurons were detected by immunohistochemistry. Success rates of PD models established by one-site and two-site injection techniques were examined. RESULTS： One rat died in the one-site injection group and four in the two-site injection group. Thus behavioral testing was performed on 31 rats. There was no significant difference in the success rate of PD model establishment between one-site injection and two-site injection groups [82% （14/17） vs. 86% （12/14）, P 〉 0.05]. The numbers of tyrosine hydroxylase -positive neurons in one-site injection and two-site injection groups were not significantly different （ P 〉 0.05）, but they were significantly lower than in the control group（P 〈 0.01 ）. CONCLUSION： A Parkinson＇s disease model can be established in rats via striatal one-site double injection.

Use of Double Differential-mode Current Injection Method Equivalent to High Level Illumination for Susceptibility Testing

To achieve the electric field strength and the induced currents in equivalence in susceptibility tests with the high-level field radiation above 400 MHz,a double differential-mode(DM) current injection method based on directional couplers is proposed.Two cascaded symmetrical directional couplers compose a coupling device to inject the DM currents.When the coupling device is used,two devices are necessary to achieve the equivalence between radiation and injection,i.e.the equivalence between the injected voltages and the field strength,which is linear,regardless of the characteristics of the equipment under test(EUT).The results are verified by experiments using typical coaxial cables and nonlinear devices,where the equivalence between the nonlinear EUT responses induced by radiation and injection at both ends is achieved by using two coupling devices.At a frequency up to 1.75 GHz,the maximal experimental error is only 3.39%.The experimental results confirm the accuracy of the proposed method even both the EUTs work in the nonlinear region.The proposed method is applicable for radiated susceptibility(RS) testing of interconnected systems in the microwave frequency band.

Injection modulation of p^+-n emitter junction in 4H-SiC light triggered thyristor by double-deck thin n-base

To overcome hole-injection limitation of p^＋-n emitter junction in 4H-SiC light triggered thyristor, a novel high- voltage 4H-SiC light triggered thyristor with double-deck thin n-base structure is proposed and demonstrated by two- dimensional numerical simulations. In this new structure, the conventional thin n-base is split to double-deck. The hole- injection of p^＋-n emitter junction is modulated by modulating the doping concentration and thickness of upper-deck thin n- base. With double-deck thin n-base, the current gain coefficient of the top pnp transistor in 4H-SiC light triggered thyristor is enhanced. As a result, the triggering light intensity and the turn-on delay time of 4H-SiC light triggered thyristor are both reduced. The simulation results show that the proposed 10-kV 4H-SiC light triggered thyristor is able to be triggered on by 500-mW/cm^2 ultraviolet light pulse. Meanwhile, the turn-on delay time of the proposed thyristor is reduced to 337 ns.

Simultaneous Determination of Gold and Platinum by Double Artificial Neural Network Analysis with Flow-injection Chemiluminescence

A highly sensitive double artificial neural network （DANN） analysis with flow-injection chemiluminescence （FI-CL） has been developed to simultaneously determine the trace amounts of the gold and platinum in simulated mixed samples, without the boring process.

Double-Injection Bifurcation Optical Active Switch Integrated on Silicon-on-Insulator for 1.3μm Operation

Based on the double-injection effect,the dual-mode interference principle and the free-carrier plasma dispersion effect,a double-injection bifurcation optical active switch integrated on silicon-on-insulator has been proposed and fabricated.Its insertion loss and crosstalk are measured to be less than 5.32 and -14.4dB,respectively,at wavelength 1.3μm and the total switching current 90mA.Response time is about 180ns.

Research on the Equivalence Between Double Differential- mode Current Injection and Radiation Test Method

There are the application scope limits for single differential-mode current injection test method, so in order to carry out injection susceptibility test for two-pieces equipment interconnected with both ends of a cable simultaneously, a double differential-mode current in- jection test method (DDMCI) is proposed. The method adopted the equivalence source wave theorem and Baum-Liu-Tesche(BLT) equation as its theory foundation. The equivalent corresponding relation between injection voltage and radiation electric field intensity is derived, and the phase relation between the two injection voltage sources is confirmed. The results indicate that the amplitude and phase of the equivalent injection voltage source is closely related to the S parameter of directional coupling device, the transmission line length, and the source vector in BLT equation, but has nothing to do with the reflection coefficient between the two equipment pieces. Therefore, by choosing the right amplitude and phase of the double injection voltage sources, the DDMCI test is equivalent to the radiation test for two interconnected equipment of a system.

Construction of a model of autologous blood intracerebral hemorrhage in rats with a double injection and double needle withdrawal and the characteristics of the operative technique

BACKGROUND ： Experimental animal models of intracerebral hemorrhag （ICH） are greatly needed, so the process of establishment should be ideal in hematoma formation and easy to operate. OBJECTIVE ： To construct model of ICH in rats with double injection of autologous blood taken from the cut tail cut and double withdrawal of the needle （shortened as two-step injection model）, and compare with those induced by single and double injections. DESIGN ： A randomized controlled tria SETTING： Department of Neurology, General Hospital of Military Area Command of Chinese PLA. MATERIALS： Thirty male Wistar rats of 10 to 12 months, weighing （400±25） g, provided by the Experimental Center of Medical Animals, General Hospital of Shenyang Military Area Command of Chinese PLA, were divided randomly into 3 groups with 10 rats in each group： two-step injection group, single injection group, double injection group. METHODS ： The experiment was carried out in the Department of Neurology, General Hospital of Military Area Command of Chinese PLA from March to June in 2004. Autologous blood ICH model in rats were established as follows： In the two-step injection group, 50 μL unclotted autologous blood was taken from the rat tail cut, then injected with microsyringe into the caudate nucleus, 10 μL injected at first, paused for 2 minutes, and then the rest 40 μL injected slowly and continuously within 2 minutes. After the injection, the needle was kept immovable for about 4 minutes, withdrawn 2.0 mm, again kept immovable for about 4 minute, and then removed wholly at a slow speed. In the single injection group, 50 μL unclotted tail blood was injected slowly and continuously all within 2 minutes and the needle was slowly removed;（4） In the double injection group, 10 mL blood was injected at first, paused for 2 minutes, the rest 40 μL injected evenly within 2 minutes, and then the needle was withdrawn slowly and uninterruptedly. Neurologic findings were scored in accordance with Longa＇s five-point scale （0-4 scores, the higher the score, the severer the neurological dysfunction）. The rats were killed to remove and sections were prepared, the morphological features of hematomas were grossly observed, the maximal diameter and size of hematomas in each slice were measured with the imaging analytical system, and the volume was calculated. Meanwhile, the conveniences of the techniques were compared. MAIN OUTCOME MEASURES： The morphological features and volume of hematomas, neurologic deficit score （NDS）, and the convenience of the techniques were compared. RESULTS： All the 30 rats were involved in the analysis of results without deletion. （1） Results of the morphological observation of volume of hematoma： In the two-step injection group, hematomas located in the right caudate nucleus area regularly in circular or analogously circular shape in each slice. The formation rate of hematomas in the single injection group and double injection group were lower than those in the two-step injection group [60% （6/10）, 80% （8/10）, 100% （10/10）, P〈 0.01, 0.05]. The volume of hematomas in the single injection group and double injection group were smaller than those in the two-step injection group [（28.5±14.8）, （33.4±7.4）, （41.6±3.9） mm3, P〈 0.01, 0.05]. （2） NDS results： The NDS scores in the single injection group and double injection group were smaller than that in the two-step injection group （0.90±0.83, 1.30±0.78, 1.90±0.57, P〈 0.05）. （3）Comparison of the convenience of the techniques： The double injection method allowed generating reproducible hematomas in rats with shortcomings that it needed autologous arterial blood from femoral artery, and precision instruments such as microinfusion pump. The two-step injection injected fresh unclotting blood taken directly from the tail cut with microsyringe into the rat brain, and it has the advantages of easy operation, no influence on the activity of thrombase, shorter duration for model establishment, and higher rate of hematoma formation, which could generate ideal and economical models of ICH. The two-step injection induced hemotoma regularly in circular or analogously circular shape in each slice, but those induced by single and double injections were mostly in strip or fusiform shapes and extending along the needle tracks or into the ventricle or subarachnoid space. CONCLUSION ： The autologous blood ICH model induced by the two-step injection method is a reproducible and reliable one in regular shape, which is better than those induced by double and single injections.

Effects of Depth of Needle Insertion with Risperidone Long-Acting Injectable in Persons with Schizophrenia: A Randomized Double-Blind Study

In some cases, if the insertion depth is shallower than expected, intramuscular (IM) injection of risperidone long-acting injectable (RLAI) may not penetrate the muscle fascia. However, if needle insertion depth is deeper than anticipated, needle penetration may cause damage to nerves, arteries and veins. Few clinical studies were done to evaluate the depth of needle length insertion reaching the intended gluteal muscle. The aim of this study was to evaluate the suitable depth of injecting RLAI. Twenty-six patients with schizophrenia were treated with RLAI, and randomly divided into two groups: 50 mm needle inserted group (Group-D, deep insertion, n = 13) and 20 mm needle insertion group (Group-S, shallow insertion, n = 13). For Group-S, the needle length was marked with a spacer at exactly 20 mm. Injections were performed by the psychiatrist or nurse, alternating between the two gluteal sites by double-cross method every two weeks. Clinical psychotic symptoms and injection site reactions were recorded throughout the study period. Experienced psychologists who were blinded from the needle-length experimental variable evaluated patients’ psychotic symptoms using the Positive and Negative Syndrome Scale (PANSS) every two weeks. The plasma 9-hydroxyrisperidone (9-OH-RIS) concentrations were measured every two weeks;comparison data were determined on the 8th week and the 14th week. No significant difference was observed in 9-OH-RIS concentrations, psychotic symptoms, injection site skin reactions of subjects in both groups. However, in Group-D, injection site adverse reactions were confirmed in two subjects (15%). In Group-S, injection site reactions were confirmed in six subjects (46%). Although effective 9-OH-RIS concentrations were obtained with the insertion using both depth, it was concluded that the 50 mm insertion length was more suitable for dorsogluteal IM injections in adult patients with schizophrenia as demonstrated by the incidence of local adverse skin reactions.

Heating of heavy oil by circulating hot water in closed double casing in ultra-deep wells

In heavy oil production,the loss of energy to ambient surroundings decreases the temperature of the heavy oil flowing upwards in a vertical wellbore,which increases the oil viscosity and the oil may not flow normally in the wellbore.Therefore,it is necessary to lower the heavy oil viscosity by heating methods to allow it to be lifted easily.Heating of heavy oil in an oil well is achieved by circulating hot water in annuli in the well（tubing-casing annulus,casing-casing annulus）.In this paper,based on heat transfer principles and fluid flow theory,a model is developed for produced fluids and hot water flowing in a vertical wellbore.The temperature and pressure of produced fluids and hot water in the wellbore are calculated and the effect of hot water on heavy oil temperature is analyzed.Calculated results show that the hot water circulating in the annuli may effectively heat the heavy oil in the tubing,so as to significantly reduce both oil viscosity and resistance to oil flow.

Simulation study of longitudinal injection scheme for HALS with a higher harmonic cavity system

Longitudinal injection is a promising on-axis injection scheme for diffraction-limited storage rings. In the latest version of the Hefei advanced light source (HALS), both the dynamic aperture and momentum aperture have been optimized. A longitudinal injection scheme was investigated on the HALS using a doublefrequency radio frequency system. To evaluate the injection performance, various errors were considered. A series of tracking simulations were conducted, and the injection efficiency was obtained under different error levels.

TWO-PHASE FLOW FOR A HORIZONTAL WELL PENETRATING A NATURALLY FRACTURED RESERVOIR WITH EDGE WATER INJECTION

This paper examines the two-phase flow for a horizontal well penetrating a naturally fractured reservoir with edge water injection by means of a fixed streamlinemodel,The mathematical model of the verical two-dimensional flow or oil-water for a horizontal well in a medium with double-porosity is established ,and whose accuratesolutions are obtained by using the characteristic method .The saturation distributionsin the fractured system and the matrix system as well as the formula of the time of water free production are presented .All these results provide a theoretical basis and a computing method for oil displacement by edge water from naturally fracturedreservirs.

基于静止轴系改进高频方波注入同步磁阻电机无传感器控制

同步磁阻电机因为其成本低、可靠性高,发展前景可观。在低速域无传感器控制方面,因同步磁阻电机转子具有凸极性,使用高频方波信号注入方法进行转子角度估计最为合适。但是,电机在低速运行中伴随着交直轴电感交叉饱和问题,该问题影响着电机的动稳态性能。为此,对传统高频方波注入控制方法进行改进,提出基于静止轴系的双高频方波注入无传感器控制方法,降低高频幅值带来的高频转矩脉动,抑制因交叉饱和效应导致的角度估计误差,提高电机动稳态性能。在1.5 kW同步磁阻电机实验平台上进行实验验证。结果表明,与传统高频注入法相比,改进高频注入法消除了交叉饱合引起的角度估计误差,并降低高频信号带来的转矩脉动问题,提高了电机的动稳态性能。

汽车激光雷达盖板的双色注塑模具设计

根据某车型激光雷达盖板的双色结构及形状,采用动模型芯旋转式结构的模具方案,设计了一套一出二的热流道双色注塑模具。利用Moldflow软件进行了双色成型分析,双色注塑第一次注射成型透明的PMMA材料的产品,第二次注射成型黑色ASA材料的产品。为实现该双色产品的结构成型,在定模处设计了2组不同结构的型腔,在动模处设计了2组左右对称的型芯,并且,在型芯侧设计了双斜导柱抽芯机构,冷却系统设计为“直通式+隔水片”的随形循环水路;顶出系统设计为2组独立的液压油缸,在产品顶出取件中,第一次注射成型的PMMA产品不顶出,第二次注射成型的ASA材料的产品采用“直顶+斜顶”的组合机构将双色产品推出,最终通过机械手完成产品的取件。实践生产证明了该双色模具结构合理、运行稳定、成型的双色塑件表面无缺陷。

轨道减振器双底模注射硫化成型工艺的研究与应用

对轨道减振器双底模注射硫化成型工艺进行研究,并与传统高压模硫化成型工艺进行对比。结果表明:双底模注射成型工艺缩短了硫化时间,实现了轨道减振器的连续化生产,同时提高了型腔内压,促进了金属与橡胶的有效粘接;双底模注射硫化成型轨道减振器疲劳后垂向静刚度和动静刚度比变化率小,垂向静刚度波动范围在10%以内,产品性能更稳定。

五里湾X1油藏如何提高采收率

靖安油田五里湾油藏以开发三叠系X1油藏为主,储层为湖成三角洲沉积,属于低渗透油藏,油藏平面、剖面非均质性较强。开发以注水为主,X1油藏目前综合含水率72.5%、采出程度25.4%,处于双高开发阶段,随着注入、采出程度的增大,油藏的平面单向突进、剖面上层内、层间矛盾日益突出,水驱油效率逐渐下降,从而影响着油田的稳产和开发效果,如何提高最终采收率是油藏开发永恒的主体。本文重点总结了X1油藏实施空泡驱、微球驱、注采井网调整、不稳定注水、精准堵水等措施后提高最终采收率,为后期整个X1油藏提高采收率提供方向。

柴油引燃天然气火焰温度场和碳烟浓度场分析

针对柴油引燃高压直喷天然气火焰温度场和碳烟浓度场尚不明确的问题,在定容燃烧弹平台上,采用高压直喷天然气共轴喷射器,利用高速彩色相机结合双色法研究了不同油/气喷射压力和油/气喷射间隔对高压直喷天然气燃烧后的火焰温度和碳烟KL值分布特性。研究结果表明:高压天然气被引燃后的火焰平均温度和碳烟平均KL值均随着油/气喷射压力的升高而降低,因此为降低碳烟KL值应提高油/气喷射压力。当油/气喷射间隔为0.8 ms时,高压天然气射流火焰平均温度最高,最高达到2318 K;当喷射间隔为0.4 ms时,火焰的平均温度最低,最低为2148 K;相同时刻下,油/气喷射间隔0.8 ms的碳烟平均KL值相较于0.4 ms的工况最多提高了112.8%,相较于喷射间隔1.2 ms的工况最多提高了49.02%;试验结果表明:为降低高压直喷天然气燃烧时的碳烟生成水平,应将喷射间隔设定在柴油喷射结束之前。本文为HPDI天然气发动机的燃料喷射策略和降低碳烟生成的相关研究提供基础参考。

双升程电控喷油器多次喷射油量波动特性研究

为实现船用柴油机高压共轨系统喷射的柔性和稳定控制,提出一种双升程电控喷油器,基于搭建的喷油器AMESim仿真模型,探究了喷油器不同多次喷射模式下的油量波动特性.结果表明:大升程预喷模式下的主喷量标准差随预喷量的增加先上升后下降,而小升程预喷模式下的主喷量标准差随预喷量呈幅值逐渐降低的波动变化趋势.总体上,在预喷量为161~660 mm^(3)范围,小升程预喷模式在降低主喷量波动程度方面比大升程预喷模式更占优势.预喷射采用小升程喷射模式且预喷量一定时,升程切换延迟为0.2 ms的靴形主喷模式在降低主喷量波动程度方面略优于相同主喷脉宽或相同单次喷射油量的大升程主喷模式.大升程和小升程后喷模式下的后喷量标准差随主喷脉宽和目标后喷量均呈波动变化趋势,且小升程后喷模式下的后喷量标准差波动程度更小.与大升程后喷模式相比,小升程后喷模式在降低后喷量波动程度方面更占优势.

顶空进样-双柱双检测器-气相色谱法分析人体血液中乙醇等12种挥发性化合物

基于GB/T 42430-2023与GA/T 204-2019的技术方法,分别在两套不同的设备平台及色谱柱体系上建立了同时分析人体血液中乙醇等12种挥发性化合物的顶空进样-双柱双检测器-气相色谱分析方法。所建立方法中酮醇类、苯类物质色谱分离基本良好;乙醇等7种酮醇类化合物线性范围为010~300 g/L,线性相关系数(r)均大于0997,检出限除正丙醇为0005 g/L外,其余化合物均为005 g/L,定量限均为010 g/L,符合标准要求;苯等5种苯类化合物的线性范围为005~50 mg/L,r均大于0995,检出限均为002 mg/L,定量限均为005 mg/L,符合标准要求;色谱柱J&W DB-BAC1 UI和色谱柱Rtx-BAC-PLUS 2上各化合物不同加标水平下的平均回收率为922%~1116%,相对标准偏差(n=6)为04%~74%。对两套不同的设备平台及色谱柱体系上乙醇的测定进行不确定度评定,乙醇的不确定度主要来源于校准曲线,取置信概率95%(包含因子k=2),能力验证样品1在色谱柱J&W DB-BAC1 UI和色谱柱Rtx-BAC-PLUS 2的测定结果分别为(120±006)g/L和(120±007)g/L,样品2在色谱柱J&W DB-BAC1 UI和色谱柱Rtx-BAC-PLUS 2的测定结果分别为(078±004)g/L和(079±005)g/L。能力验证样本分析与z比分数评价展示了所建立方法的数据可靠性;甲醇及有机溶剂中毒患者样本分析结果表明,所建立方法适用于人体血液等体液中乙醇等7种酮醇类化合物和5种苯类化合物的高精度定量分析,可用于司法鉴定、中毒检测等实践场景。

轴向喷气对断油高速滚动轴承油膜运动特性影响

高速轴承断油后轴承腔内的油膜运动特性直接影响着轴承的抗断油能力。为进一步提升现有轴承的抗断油能力,采用VOF和多重参考系模型相结合的方法,系统研究喷气位置、喷气流量以及喷气角度变化对断油轴承腔内流体流动和温度场的影响。结果表明:在研究的喷气流量范围内,喷气流量变化对断油后轴承腔内油膜运动影响较小,而喷气位置和喷气角度对断油后轴承腔内的油膜运动特性具有重要影响,喷气位置在保持架上侧和喷气角度为0°时,可以延缓轴承腔内润滑油的流失,使滑油分布更均匀,从而使其具有更好的润滑冷却性能。

船舶双三相永磁同步电机高频注入算法研究

传统高频信号注入法只适用于具有凸极特性的永磁同步电机,并且在位置估计和电流反馈环节引入多个滤波器,造成位置估计和电流响应延迟,降低了系统的动态性能。针对凸极特性不明显的表贴式双三相永磁同步电机,在低速阶段提出一种基于高频方波电压注入法的无位置传感器控制策略,将高频注入周期和磁场定向控制周期分离,高频注入周期内直接在两相静止轴系采样高频响应电流进行转子位置估计,且位置估计和电流反馈环节均未使用滤波器。通过理论分析和仿真验证了该控制策略的有效性。