银曲胶囊对高脂血症大鼠血脂的影响

目的 观察银曲胶囊对实验性高脂血症大鼠血脂水平的影响。方法 大鼠用高脂饲料喂养2 周以造成脂代谢紊乱模型, 并根据体重或血清中总胆固醇水平随机分为模型组、血脂康组和银曲胶囊大、中、小3 个剂量组(0.5 、1.0 、2.0 g/kg)。采用预防和治疗给药, 通过测定大鼠血清中总胆固醇、甘油三酯等水平, 观察银曲胶囊对实验性大鼠血脂的影响。结果 在预防和治疗实验中, 银曲胶囊大、中、小3 个剂量组血清中总胆固醇、甘油三酯、低密度脂蛋白、极低密度脂蛋白等水平与模型组比较均有一定程度降低, 高密度脂蛋白水平略升高(P<0.05 或P<0.01)。结论 银曲胶囊对实验性高脂血症大鼠有一定的防治作用。     

阿托伐他汀对自发性高血压大鼠心室重构的影响

目的: 观察阿托伐他汀对自发性高血压大鼠(SHR)心室重构的影响。方法: 24只SHR 随机分为4组,每组6只。SHR对照组、阿托伐他汀50mg组(50mg·kg^-1·d^-1)、阿托伐他汀10mg组(10 mg·kg^-1·d^-1)和缬沙坦组(20mg·kg^-1·d^-1);6只Wistar-Kyoto 大鼠(WKY)作为正常对照组。灌胃给药共6 周,分别于给药前和给药后每2 周测量大鼠尾动脉收缩压(SBP)。酶法测定血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)及低密度脂蛋白胆固醇(LDL-C)含量,放免法测定血浆和心肌血管紧张素Ⅱ(Ang Ⅱ)水平,并检测心肌羟脯氨酸、胶原蛋白含量和全心重量(HW)、左室重量(LVM)及左室重量指数(LVMI)。透射电镜观察心肌超微结构改变。结果: 用药前SHR 各组SBP均显著高于WKY 正常对照组(P<0.01),给药后第4、6 周,阿托伐他汀50 mg 组SBP明显下降(P<0.01),阿托伐他汀10 mg 组不明显;缬沙坦组自给药后第2 周,SBP明显下降(P<0.01)。阿托伐他汀50 mg 组TC、TG 及LDL-C水平较SHR 对照组明显降低(P<0.05或P<0.01),阿托伐他汀10 mg 组仅LDL-C 水平明显下降(P<0.05)。SHR对照组血浆Ang Ⅱ浓度与WKY 正常对照组比较无显著性差异,但心肌Ang Ⅱ浓度明显增高(P<0.05);给药6 周后,阿托伐他汀各剂量组和缬沙坦组血浆Ang Ⅱ浓度显著高于SHR 对照组(P<0.01),而心肌Ang Ⅱ 浓度在阿托伐他汀50 mg 组和缬沙坦组明显降低(P<0.05)。SHR 对照组心肌羟脯氨酸和胶原蛋白含量较WKY 正常对照组明显升高(P<0.01);6 周后,阿托伐他汀50 mg 组较SHR 对照组降低(P<0.05)。SHR组HW、LVM和LVMI与WKY正常对照组相比增高(P<0.01),而阿托伐他汀50 mg 组却低于SHR 对照组(P<0.05)。透射电镜观察心肌超微结构显示,阿托伐他汀50mg组和缬沙坦组与SHR对照组比较,心肌细胞核膜较完整,肌原纤维清晰,排列较整齐,横纹清楚,间质胶原纤维无明显增生。结论: 阿托伐他汀能明显改善SHR 的心室重构,降低血压和心肌Ang Ⅱ浓度可能为其机制之一。     

L-精氨酸对应激性大鼠血压的影响1

目的 研究L-精氨酸(L-ARG)对应激性大鼠血压(BP)的影响。方法 给SD 大鼠的饮水中添加L-ARG,并给予间断性足底电刺激15 d,隔日监测尾动脉BP 1 次,观察其尾动脉BP 的变化情况和血浆一氧化氮(NO)浓度变化。并与单纯应激组和正常对照组比较。结果 单纯应激组在d 9 、d 11 、d 13 、d15,BP 升高,与正常对照组相比,差异有显著的统计学意义(P <0.05或P <0.01);血中NO 的浓度低于正常对照组(P <0.05)。L-ARG+应激组隔日测得BP 与对照组相比,其差异无统计学意义,d 15 BP 低于正常对照组(P <0.05),BP 呈下降趋势,NO 明显升高(P <0.01)。结论 L-ARG 有阻抑应激性大鼠BP 升高的作用。     

柴葛通脉口服液对实验性高脂血症小鼠血脂的干预作用

目的 观察柴葛通脉口服液对实验性高脂血症小鼠血脂的干预作用。方法 取健康昆明系小鼠制成高脂血症模型, 同时给予不同剂量的柴葛通脉口服液或烟酸4 wk, 眼眶取血测定血脂, 观察胆固醇(TC)和甘油三酯(TG) 的变化。结果 高脂模型组TC、TG 明显高于正常对照组(P <0.05), 烟酸组TC 降低不明显(P >0.05), TG 降低明显(P <0.05); 而柴葛通脉口服液TC、TG 降低均很明显(P <0.05或0.01), 且随剂量增加而增强, 有明显的量效关系。结论 柴葛通脉口服液具有预防小鼠高脂血症发生发展的作用。     

阿托伐他汀对自发性高血压大鼠肠系膜动脉平滑肌细胞大电导钙激活钾通道的影响

目的: 探讨阿托伐他汀对自发性高血压大鼠(SHR) 动脉血压及肠系膜动脉平滑肌细胞大电导钙激活钾通道(large-conductance calcium-activatedpotassium channel, BKCa,MaxiK) 的影响。方法: 选取雄性9 周龄SHR12 只, 随机分为阿托伐他汀组(AVT 组) 、蒸馏水组(DW 组), 每组6 只, 以Wistar-Kyoto 大鼠为对照组(WKY 组) (n =6) 。AVT 组以AVT 加适量蒸馏水灌胃10 周(50 mg·kg^-1·d^-1) 。观察给药前后大鼠腹主动脉血压的变化, 测定大鼠血清TC 、TG 及高密度脂蛋白胆固醇(HDL-C) 含量。利用膜片钳全细胞模式记录肠系膜动脉平滑肌细胞钾电流、用四乙胺阻断大电导钙激活钾通道后的电流、膜电容, 以计算BKCa 电流值、电流密度。结果: AVT 组腹主动脉血压明显低于DW 组[(171±8) mm Hg vs (190±10) mm Hg, P<0.01] (1 mm Hg =0.133 kPa) ;与DW 组相比,AVT 组肠系膜动脉平滑肌细胞BKCa电容减低[(23.8 ±2.6) pF vs (30.0±2.5) pF, P<0.01] 而电流密度则显著高于DW 组[(13.2±1.2) pA /pF vs (9.2±1.2) pA /pF, P<0.01) ], 与WKY 组比较未见明显差异。结论: 长期应用阿托伐他汀可降低SHR 血压, 其机制可能是AVT 影响BKCa 活性, 调节血管张力。     

国产和进口佐匹克隆对大鼠杏仁核点燃作用的对比研究

目的 国产和进口佐匹克隆对大鼠杏仁核点燃作用的对比研究。方法 用雌性Wistar大鼠建立杏仁核点燃模型。对杏仁核点燃大鼠分别灌胃1.5 、3、5 mg ·kg^-1 国产和进口佐匹克隆;溶剂(西黄蓍胶浆)作为阴性对照。观察口服给药前和给药后30 min 大鼠行为发作强度和脑后放电(af ter discharge,AD)时程。结果 3 、5 mg ·kg^-1 国产和进口佐匹克隆均能明显减弱大鼠行为发作强度, 缩短AD 时程, 用药前后自身比较差异均有非常显著性(P<0.01), 两药间差异无显著性意义(P>0.05)。结论 国产和进口佐匹克隆都能抑制点燃效应, 其作用强度两药基本相等。     

芝麻素对代谢综合征大鼠血糖、血脂及主动脉血管细胞黏附分子-1 蛋白表达的影响

目的:探讨芝麻素对代谢综合征大鼠血糖、血脂及主动脉血管细胞黏附分子-1(VCAM-1) 蛋白表达的影响。方法:高脂高糖诱导大鼠代谢综合征24 周, 于诱导第9 周连续口服芝麻素(120 、60 、30 mg^。kg^{-1 。}d^-1 ) 16 周后, 称大鼠体重、腹部脂肪重量, 测血脂、血糖、血清总抗氧化能力和血清过氧化氢含量。HE 染色观察主动脉病理变化, 免疫组化法观察主动脉VCAM-1 蛋白表达。结果:芝麻素120 、60 mg/kg 组体重与腹部脂肪重量明显低于模型组(P <0.01), TG 、TC 、低密度脂蛋白胆固醇(LDL-C) 和血糖水平明显降低(P <0.01), 高密度脂蛋白胆固醇(HDL-C) 水平明显升高(P <0.01) ;主动脉VCAM-1 蛋白表达明显减少, 病理损伤明显减轻;血清与血管总抗氧化能力明显提高, 过氧化氢含量明显减少。结论:芝麻素可以降低代谢综合征大鼠血糖、血脂及主动脉VCAM-1表达, 减轻血管病理损伤, 具有防治动脉粥样硬化的作用。     

丹参饮促进胃溃疡愈合作用及其机理研究

目的: 观察丹参饮对大鼠乙酸性胃溃疡的影响并探讨其作用机制。方法: 应用大鼠乙酸性胃溃疡模型, 给予丹参饮治疗14 d 后, 观察胃粘膜损伤程度(UI), 检测血清NO含量和血浆PGE₂水平, 测定胃壁结合粘液的含量、溃疡边缘粘膜细胞凋亡(AI)、凋亡相关基因Bcl-2 以及表皮生长因子受体(EGFR) 的表达。结果: 与模型组相比, 丹参饮可明显促进大鼠溃疡愈合(P <0.01), 提高血清NO 、血浆PGE₂ 和胃壁结合粘液含量(P < 0.05), 并显著抑制胃溃疡边缘粘膜细胞凋亡(P <0.01), 同时促进EGFR 和凋亡抑制基因Bcl-2 的表达, 其中7、3.5g·kg^-1剂量组作用更为显著(P < 0.01) 。结论: 通过胃粘膜防御因子及抑制凋亡途径来促进溃疡愈合可能是丹参饮治疗胃溃疡的作用机制之一。     

理气活血中药防治大鼠血管内皮细胞损伤的实验研究1

目的 观察理气活血中药对大鼠血管内皮细胞(VEC)损伤的防治作用。方法 建立大鼠VEC 损伤模型, SD 大鼠30 只, 随机分为正常对照组、模型组、理气活血组, 每组各10 只。检测并比较循环内皮细胞(CEC)计数、t-PA、PAI 活性、6-keto-PGF_1α含量及血小板最大聚集率(PAg T_max)等指标变化。结果 理气活血组与模型组比较, CEC 计数明显减少(P <0.01);t-PA 活性明显增强(P<0.01), PAI 活性降低(P <0.05), 活性型t-PA升高(P <0.01);6-keto-PGF_1α 含量升高(P<0.01);PAg T_max下降(P <0.01)。结论 理气活血中药能增强VEC 的抗凝及促纤溶功能, 具有良好的VEC 保护作用。     

慢性低O2高CO2大鼠血管内皮生长因子表达及参一胶囊的影响

目的 探讨血管内皮生长因子(VEGF) 在低氧性肺动脉高压形成中的意义及参一胶囊对其影响。 方法 采用ELISA 法、透射电镜、原位杂交技术等方法, 观察正常对照组、低O₂ 高CO₂ 4 周组、低O₂ 高CO₂ 4 周+参一胶囊组大鼠肺动脉平均压(mPAP)、右心室重量比(RV/LV +S)、血清和肺组织的VEGF的含量、肺细小动脉的超微结构、肺组织VEGFmRNA表达的变化。 结果 低O₂ 高CO₂ 组大鼠的mPAP、RV/LV +S、血清和肺组织的VEGF 的含量明显高于正常对照组(P <0.01)。低O₂ 高CO₂ 4 周+参一胶囊组大鼠mPAP、RV/LV +S、血清VEGF 显著低于低O2 高CO₂ 组(P <0.01), 肺组织的VEGF 的含量也低于低O₂ 高CO₂ 组(P <0.05)。低O₂ 高CO₂ 组大鼠肺细小动脉中膜平滑肌细胞明显增生、胶原纤维较正常对照组增多, 低O₂ 高CO₂ 4 周+参一胶囊组较低O₂ 高CO₂ 组则明显减轻。原位杂交显示低O₂ 高CO₂ 组大鼠肺细小动脉VEGFmRNA 较正常对照组明显增加(P <0.01), 而低O₂ 高CO₂ 4周+参一胶囊组与低O₂ 高CO₂ 组比较, 则明显降低(P <0.05)。 结论 VEGF 参与了慢性低氧性肺动脉高压的形成, 参一胶囊可通过抑制VEGF 的作用而有效地降低肺动脉高压。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。