血管紧张素Ⅱ在岛叶皮层引起的升压反应经缰核、下丘脑传导

研究证明了血管紧张素Ⅱ(AngⅡ)能引起岛叶皮层(INS)的升压反应,也是向缰核(Hb)、下丘脑(Hypot)传递反应的介导物.电刺激INS,或向INS注射AngⅡ,向缰核,下丘脑微量注射AngⅡ拮抗剂鲁莎坦(Losartan 100 ng/ μL)或利多卡因等条件下,从股动脉插管经压力换能器,可以记录动脉血压的变化.电刺激(150～250 μA,3 s)INS可引起升压反应,血压升高绝对值为(2.14±0.64)kPa.向Hb,Hypot单侧或双侧注射盐酸利多卡因(2%,3 μL),使电刺激INS引起的升压明显降低,表明Hb,Hypot是电刺激INS实现升压效应的必经之路.向INS注射AngⅡ(0.3 μL,15 ng,pH 5.0),引起血压升高幅度为2.26 kPa.在Hb单侧注射鲁莎坦,则INS注射AngⅡ的血压上升幅度仅为1.56 kPa,较原升压幅度降低29.42%.向Hb双侧注射鲁莎坦,则INS的升压效应降低42.99%.在Hb单侧或双侧注射等量人工脑脊液不能降低AngⅡ引起的升压效应.     

TRH在家兔蓝斑复合核的升压效应及其机制初探

实验在35只鸟拉坦静脉麻醉.切断双侧颈迷走神经.制动.人工呼吸家兔上进行.采用脑内核团微量注射方法,观察到促甲状腺素释放激素(TRH)注入蓝斑复合核(Lc—Sc)可引起明显的升压效应,而对心率无明显影响.在延髓头端腹外侧区(RVLM)内分别预注射α_1、α_2和β受体阻断剂,均能拮抗TRH在家兔蓝斑复合核的升压效应.结果提示:TRH在家兔蓝斑复合核具有升压效应.其机制可能通过RVLM区的α和β受体介导.     

GnRH-A免疫母兔对血清LH和FSH浓度的作用

目的：探讨促性腺激素释放激素类似物（GnRH-A）对动物性腺激素分泌的作用与机理,为临床应用奠定基础．方法：以EDC-HCL为偶合剂,将GnRH—A与BSA连接为复合物,制备GnRH—A抗原．24只日本大耳白兔分为四组,在实验I组、实验Ⅱ组和实验Ⅲ组兔子的颈背部分别皮下注射1．0mL（100μg,／mL、100μg／mL和50μg／mL）GnRH—A抗原,实验Ⅱ组和实验Ⅲ组于第3周以相同剂量加强注射一次,在实验的不同时间采血、分离血清,用ELISA法测定促卵泡刺激素（FSH）和促黄体生成素（LH）含量．结果：EG-Ⅱ和EG-Ⅲ的FSH浓度在注射后30d开始升高,至40d达到峰值。EG-Ⅱ和EG-Ⅲ明显高于EG-Ⅰ和对照组及EG-Ⅲ（P〈0．05）,整个实验期间EG-Ⅰ和对照组无显著差异．EG-Ⅱ和EG-Ⅲ的LH注射后不断升高,在40d至峰值（P〈0．05）,此后降低,30d～50d时EG-Ⅱ明显高于EG-Ⅰ和EG-Ⅲ及对照组．结论：兔体内注射GnRH-A可以明显增强LH和FSH的合成与分泌,加强注射效果更明显,而且与注射剂量相关,持续时问为40d左右．     

具有单步死区时间控制的3态降压-升压直流-直流转换器

为了提高能量转换效率,扩大输入输出电压范围,研究了在直流-直流转换器中功率传输门结构及死区时间对SMPS(switched-mode power supply)转换器效率与稳定性的影响.不适当的死区时间会产生直流通路导通(cross-conduction)及体2极管导通(body-diode conduction)现象影响转换效率,提出单步死区时间控制的方法使能量转换效率更高.根据3态非反向降压-升压转换器工作原理,分别分析了功率传输门可以扩大输入输出电压范围的工作原理,提出传输门结构可以用来替代输出级上管.基于降压-升压转换器及FPGA开发板,搭建了直流-直流降压-升压转换器测试系统.该转换器输入电压Vin范围为2.7~5.7 V,输出电压Vout为0.3~6.8 V,输出电流可以高达6 A,转换效率可提高4%.     

白藜芦醇对卵巢切除大鼠动脉血压及升压反应的影响

选用雌性Wistar大鼠,体重214.07±4.85 g,于双侧卵巢切除后分别皮下注射白藜芦醇RES(0.4 mg/kg)和17β-雌二醇EST(1 mg/kg)或等量溶媒芝麻油,以假手术大鼠作为对照.处理21天后,观察去势鼠及RES或EST替代治疗大鼠对血管紧张素Ⅱ、去甲肾上腺素、肾上腺素的升压反应以及压力感受性反射敏感性的变化.结果发现去势大鼠收缩压(SP)、舒张压(DP)和平均动脉压(MAP)明显升高,但皮下分别注射RES或EST后,SP,DP和MAP明显降低.去势鼠对AngⅡ,NA和Adr升压反应明显减弱,MAP的升高值明显减小.皮下注射RES或EST后,去势鼠对AngⅡ和NA敏感性均有不同程度的恢复,但皮下注射RES后,去势鼠对Adr的反应无明显改善.去势鼠颈动脉窦压力感受性反射的敏感性明显减弱,表现为其升压反射中MAP的升高明显低于假手术大鼠.结果表明去势鼠静息动脉血压升高,对升压剂AngⅡ,NA,Adr和颈动脉窦压力感受性反射的升压反应明显减弱.皮下分别注射EST结构类似物,即植物雌激素RES后,去势鼠对AngⅡ,NA和颈动脉窦压力感受性反射的升压反应与EST相似均有不同程度的恢复.     

关于D.G.James的一个问题的解答

D心·Ja哪“曾提出一个问题,在局部环R上,当di叻V)3,公妻1时,.对任意两个理想A、B,夕(V,AB)=〔忍(V,A),卫(V,.B)〕吗?〔1〕本文解决了这个问题.同时对线性群.辛辟也考虑了相应的问题,即〔SC(V,A),S口(V,.B)〕二SC(V,AB),SSP(V,AB)=〔55尸(V,A),SSP(V,召)〕. 设R是具有极大理想卿一与剩余域F一R/形的局部环.V表”维R空间,如A是R的理想,则有自然环态射刀护R、R/A,它导出R、态射刀A:V,V/AV,刀A确定一个群态射月尸GL(V)、GL(V/AV),这一态射由: (又A“)H=H人“爹含出. 定义:对理想A,水平A的一般同余子群是: GC(V,A)…     

淫羊藿对正常和应激大鼠血压的影响

采用侧脑室注射(icv)的方法,观察了淫羊藿(Herba epimedium,HE)对正常和应激性高血压(stress-induced hyportension,SIH)大鼠动脉血压的影响,并探讨了其中枢降压效果的作用机制.结果表明:常规水煮提取的淫羊藿总黄酮(TFE)对正常大鼠和应激性高血压大鼠平均动脉血压(MAP)均有降低作用,注药前后差异显著(P<0.05);而用荷包牡丹碱(bicu-culline)阻断γ-氨基丁酸A(GABAA)受体可以影响TFE的降压效应.说明侧脑室注射TFE具有降压效应,其降压机制可能与GABAA受体相关.     

卤化物VCl_2在D_(3d)晶体场中吸收光谱的解释

一、引言自然界中存在大量的具有3d~3■电子组态的过渡金属离子V(Ⅱ)、Cr(Ⅲ)和Co(Ⅱ)所构成的络合物,在这些络合物中,不少晶体具有低对称度D_(3d)的立体结构,研究其中某一典型例子,对于该大类的络合物的晶场光谱和磁学性质的讨论具有一定的代表作用.VCl_2属晶体类AX_2(A=M(Ⅱ);X=Cl,Br,Ⅰ)的卤族元素络合物。对于晶体类AX_2,中心金属离子和卤素配体X-之间存在强的共价键效应,利用中心金属自由离子A(Ⅱ)的d     

Λ-可约的Heegaard分解

本文研究Heegaard分解沿着其中的本质扩展平环的分解.若带边3-流形M中有相对于其Heegaard分解V∪SW的本质扩展平环,则称V∪SW是Λ-可约的.对于Λ-可约的Heegaard分解V∪SW,依据其本质扩展平环A是不分离或是分离的,我们可以对V∪SW进行Ⅰ型Λ-分解M→AM1∪M2,或Ⅱ型分解V∪SW→AV1∪S1W1∪V2∪S2W2.进一步,我们定义了Heegaard分解的Λ-和,证明了Heegaard分解的Λ-和素分解的有限存在性定理.     

作用于肾上腺素受体药物对不同动物血压的影响

目的:探讨作用于肾上腺素受体药物对家兔及大鼠血压的影响.找出最适合学生的实验方法.方法:利用直接测定血压方法观察肾上腺素(AD)、去甲肾上腺素(NA)、异丙肾上腺素(ISP)、酚妥拉明分别对大鼠及家兔血压有何影响.结果:AD对大鼠血压呈现双相效应,而对家兔仅有升压作用.NA对大鼠和家兔均可引起升压作用.ISP可引起大鼠血压降低,而对家兔血压几乎无影响.预先用酚妥拉明引起降压再用AD、NA、ISP后,对大鼠可见到AD的血压翻转效应,使NA的升压效应减弱或消失,而对ISP的血压几乎无影响;对家兔无AD的血压翻转效应,可使NA的升压效应减弱或消失,而对ISP的血压几乎无影响.结论:作用于肾上腺素受体药物对大鼠的血压影响与人最接近,建议使用大鼠做此实验.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of