Purinergic control of the quail rectum: modulation of adenosine 5'-triphosphate-mediated contraction with acetylcholine     

Shiina T  El-Mahmoudy A  Khalifa M  Draid M  Shimizu Y  Takewaki T 《Research in veterinary science》2007,82(2):246-251

Electrical field stimulation (EFS) induces frequency-dependent contractions of the longitudinal muscle of isolated quail rectum which were sensitive to tetrodotoxin. The aim of the present study was to investigate whether purinergic neurons are implicated in the response to nerve stimulation. The shape of the EFS-induced contractile response was different depending on stimulus frequency; low frequencies (0.5-2 Hz) induced fast monophasic contractions with a small subsequent relaxation; whereas higher frequencies (5-50 Hz) induced biphasic contractile response that comprised fast initial component (as in case of low frequency) and a slow delayed contractile component in addition to the relaxation that follows the fast contractile component. Prior application of atropine (10 microM) completely abolished the slow delayed component but significantly enhanced the fast initial contractile component. Physostigmine (1-10 microM) significantly enhanced the slow delayed component with an inhibitory effect on the initial fast component. The nonspecific purinergic receptor antagonist, suramin (100-500 microM) significantly inhibited the fast initial contractile component with no significant effect on the slow delayed one. Complete blockade of the fast component was achieved by prior application of a combination consisted of suramin (50 microM) and pyridoxicalphosphate-6-azophenyl 2',4'-disulphonic acid tetrasodium (PPADS; 10 microM). Exogenous applications of adenosine 5'-triphosphate and acetylcholine (10 microM each), produced contractile responses that mimicked those induced by EFS. These data suggest that ATP is the main noncholinergic excitatory transmitter controlling the contractile activity of the quail rectum; and that its action could be modulated by acetylcholine.  相似文献   

励磁功率单元主回路快速故障诊断策略     

刘伟  张朕滔  梁康有  谭宇航 《保鲜与加工》2015,(4):137-145

分析总结了发电机组励磁系统功率单元的故障类型和常见故障,通过Matlab仿真功率单元主回路故障类型,重点研究基于故障频谱分析的定量故障特征提取和故障分类,提出了一种快速针对功率单元主回路的故障诊断真值表法,最后通过实验平台验证故障类别,结果表明：该方法能够正确有效地诊断出功率单元主回路具体的故障晶闸管,为励磁系统功率单元故障诊断提供依据。  相似文献   

Antioxidant,anti-amylase and anti-glycation potential of brans of some Sri Lankan traditional and improved rice (Oryza sativa L.) varieties     

《Journal of Cereal Science》2014,59(3):451-456

Brans of 23 traditional and 12 improved (both red and white) rice varieties in Sri Lanka were screened for anti-amylase and anti-glycation activities in vitro. Varieties which showed the highest inhibitory activities at screening were further investigated for anti-glucosidase and glycation reversing as anti-diabetic properties. The same varieties were studied for selected antioxidant properties. Significantly high anti-amylase and anti-glycation activities were observed for bran extracts of red varieties compared to white varieties at screening. Traditional red rice varieties, Masuran, Sudu Heeneti, Dik Wee and Goda Heeneti, exhibited significant and dose dependent anti-amylase, anti-glycation and glycation reversing activities. These varieties also showed marked antioxidant properties. It is concluded that brans of Sri Lankan traditional red rice varieties Masuran, Sudu Heeneti, Dik Wee and Goda Heeneti may be potential food supplements for diabetes.  相似文献   

An Improved Method of the Transient Waveform Analysis in Power Systems     

Wang Jianping Mi Linshu Chen Gang 《保鲜与加工》1993,(6):32-37

The angular frequency and decaying constant of each copmonect for the transient waveform in power systems were obtained by using the discrete Fourier transform; the amplitude and phase angle were calculated in the linear curve fitting method. And all of the parameters obtained above were treated in an unified optimization by using the curve fitting optimization of the least square method of general nonlinear funcrion so as to get the results of waveform analysis. Two examples are included.  相似文献   

Automatic Measuring Method of Eyeglass Lens Power     

YANG Bing-shang  LIAO Hai-yang 《保鲜与加工》2006,(10):65-68

A method of measuring eyeglass lens power is proposed. A position detector and 3 beams of ray are used to measure the prismatic, spherical and astigmatic powers. Based on the method, an automatic focimeter with simple structure can be developed. The measure errors of prismatic and spherical powers are analyzed, from which it is concluded that the precision of the position detector is the key to the method.  相似文献   

Distributed Power Flow Method Based on Ward Equivalent     

YAN Wei  HE Ning 《保鲜与加工》2006,(11):36-40

With interconnecting and developing of power system, the problem of power flow computation on dispersed data resource need to be solved. A new distributed computation method of power flow based on Ward equivalent is presented. According to master-slaver splitting principle, multi-area interconnected power system is divided into master-slaver areas. Boundary buses in different areas are defined as different bus-types. Neighborhood areas are equivalent by Ward equivalent principle, and the equivalent injection power and equivalent impedance are worked out. Power flows from master area to slaver areas are solved by Newton method, and the equivalent injection power and equivalent impedance on the boundary are modified by their solutions. The process above repeats until to convergence. The proposed distributed power flow method takes full advantage of the information of power, voltage, network configuration in neighborhood areas, so it is better on convergence and quality of solution. The proposed algorithm is testified by IEEE 14-bus system and a practical 181-bus system.  相似文献   

A Detecting Method of Harmful Currents in Three-Phase Four-Wire Asymmetrical System     

ZHOU Lin  YI Qiang  QIN Mei  ZHOU Xiao jun  YE Yi lin 《保鲜与加工》2002,(10):9

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The Staged Simulation Method for Power Electronics Circuits     

Llao Changchu 《保鲜与加工》1994,(4):119-124

This paper in troduces a staged simulation method fur power electronics circuits,presents an exampleued the method for the CSI/IM drive system.  相似文献   

Electro-circuit Design About the Data Acquisition and Wireless Transmission System Based on High-speed SCM     

YAO Peng  XIE Zhi-jiang  YU Zhong-yun 《保鲜与加工》2006,(4):9-11

Considering the difficult of acquiring and transmission the signal from the moving equipment, a new fault diagnosis monitoring system is presented. The system acquires the state signal from the moving equipment by data acquisition module that based in W77E58 high-speed SCM, and transmits the data fast by wireless mode. The signal data can be use for fault diagnosis and precise analysis. The system has the ability for acquiring abundance of data with a high speed, the ability for high accuracy data conversion, and has a function of programme controlling gain and programme controlling low-pass filtering. The successful application of this system on the vibration monitor about the material-transporting bogie in an iron works of a domestic steel enterprise proves the stability and credibility about the design project, also testifies its practical value and versatility.  相似文献   

Transmission Congestion Management Based on Power Influence Coefficient     

LI Chun-yan  YU Ji-hui  ZHANG Qian 《保鲜与加工》2007,(3):31-35

Basing eliminating on the idea that the generator who has the most influence on the power flow of line is mostly in favor of transmission congestion, the model of congestion management with the object of minimizing adjustments of bufions varied with generation outputs is proposed. It can eliminate the congestion effectively by judging the generators who should be adjusted and the amounts of adjustment. The test on IEEE-RTS24 buses system and other practical systems show that the proposed method is effective.  相似文献