scholarly journals The Coronary Dilation Effect of Shen Fu Injection Was Mediated through NO

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e92415 ◽  
Author(s):  
Yu Hong Li ◽  
Bin Yu ◽  
Zhen Zhen Duan ◽  
Olunga Mary Akinyi ◽  
Jia Hui Yu ◽  
...  
Keyword(s):  
Dilation Effect ◽  
Coronary Dilation

Species-dependent hemodynamic effects of adenosine A3-receptor agonists IB-MECA and Cl-IB-MECA

1999 ◽  
Vol 276 (6) ◽  
pp. H2076-H2084 ◽  
Author(s):  
Robert D. Lasley ◽  
Prakash Narayan ◽  
M. Salik Jahania ◽  
Elizabeth L. Partin ◽  
Kathleen R. Kraft ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Rat Heart ◽  
Coronary Flow ◽  
Receptor Activation ◽  
Isolated Rat Heart ◽  
Pressure Effects ◽  
Hemodynamic Effects ◽  
Receptor Agonists ◽  
Coronary Dilation ◽  
Isolated Rat

The purpose of this study was to compare the hemodynamic effects of the adenosine A3-receptor agonists N 6-(3-iodobenzyl)-9-[5-(methylcarbamoyl)-β-d-ribofuranosyl]adenine (IB-MECA) and 2-chloro- N 6-(3-iodobenzyl)-9-[5-(methylcarbamoyl)-β-d-ribofuranosyl]adenine (Cl-IB-MECA) in isolated rat and rabbit hearts and in the intact, open-chest pig. Isolated hearts perfused with Krebs-Henseleit buffer at a constant pressure (70 mmHg) were treated with 50 nM of either IB-MECA or Cl-IB-MECA. Neither IB-MECA nor Cl-IB-MECA altered ventricular function or heart rate in the isolated rat and rabbit hearts, and neither agent altered coronary flow in the rabbit. However, 2 min of IB-MECA treatment in the isolated rat heart increased coronary flow by 25%, an effect that did not exhibit tachyphylaxis. The IB-MECA-induced coronary dilation was only partially attenuated by the adenosine A3-receptor antagonist MRS-1191 (50 nM). IB-MECA-induced coronary dilation was completely blocked by the adenosine A2a-receptor antagonist 7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine (Sch-58261, 50 nM). Cl-IB-MECA (50 nM) did not increase coronary flow in the rat, but 100 nM did increase flow by 18%. In pentobarbital sodium-anesthetized pigs IB-MECA (5 μg/kg iv) decreased systemic blood pressure and increased pulmonary artery pressure, effects that did exhibit tachyphylaxis. These results illustrate that adenosine A3-receptor agonists produce species-dependent effects, which in the rat heart appear to be caused by adenosine A2a-receptor activation.

scholarly journals Characteristic Variability Time Scales of Long Gamma-Ray Bursts

2003 ◽  
Vol 214 ◽  
pp. 339-340
Author(s):  
Rongfeng Shen ◽  
Liming Song
Keyword(s):  
Power Density ◽  
Time Scales ◽  
Time Domain ◽  
Time Scale ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Time Dilation ◽  
Dilation Effect ◽  
The Time Domain ◽  
Intrinsic Characteristic

We determine the characteristic variability time scales for 410 bright long GRBs by locating the maximums of their Power Density Spectra (PDSs) defined and calculated in the time domain. The averaged characteristic variability time scale decreases with peak fluxe. This is consistent with the time dilation effect expected by cosmological origin of GRBs. The occurrence distribution of the characteristic variability time scale shows bimodality, which might be interpreted as that the long GRB sample is composed of two sub-classes with different intrinsic characteristic variability time scales.

Coronary dilation with carotid chemoreceptor stimulation in cardiac-denervated dogs

1988 ◽  
Vol 255 (6) ◽  
pp. H1330-H1335
Author(s):  
Masayoshi Nagata ◽  
Robert Pichet ◽  
Michel Lavallee
Keyword(s):  
Adrenergic Receptors ◽  
Conscious Dogs ◽  
Base Line ◽  
Adrenergic Blockade ◽  
Coronary Resistance ◽  
Coronary Vasodilation ◽  
Similar Extent ◽  
Cardiac Denervation ◽  
Coronary Dilation ◽  
Cardiac Nerves

The coronary vasodilation that is secondary to carotid chemoreceptor stimulation (CCS) was compared in normal (N) and in cardiac-denervated (CD) conscious dogs. Under base-line conditions, CD only differed from N dogs by greater ( P ≤ 0.01) increases in mean arterial pressure (MAP) with CCS. Coronary blood flow (CBF) increased similarly in N (146 ± 18%) and CD (126 ± 15%) dogs, and coronary resistance (CR) fell to a similar extent in N (53 ± 3%) and CD (43 ± 5%) dogs. After muscarinic and β-adrenergic blockade, CCS resulted in similar increases in MAP in N and CD dogs; increases in CBF averaged 122 ± 15 and 115 ± 12% in N and CD dogs, respectively. Decreases in CR with CCS averaged 46 ± 3 and 40 ± 5% in N and CD dogs, respectively. α1-Adrenergic blockade prevented the increases in MAP with CCS and resulted in smaller (P < 0.01) increases in CBF, similar in N (77 ± 13%) and in CD (69 ± 10%) dogs. CR fell to the same extent in N (40 ± 4%) and CD (37 ± 5%) dogs. Additional blockade of agr2-adrenergic receptors further limited the increases in CBF with CCS in N (20 ± 5%) and CD (28 ± 7%) dogs; decreases in CR were attenuated similarly in N (13 ± 5%) and CD (21 ± 5%) dogs. Thus, in conscious dogs, cardiac nerves contribute little to the coronary dilation after carotid chemoreceptor stimulation. chemoreflex; α-adrenergic receptors; cardiac denervation Submitted on January 11, 1988 Accepted on July 28, 1988

Improving Damping Properties of Railway Ballast by Addition of Tire-Derived Aggregate

2019 ◽  
Vol 2673 (5) ◽  
pp. 299-307 ◽  
Author(s):  
Weimin Song ◽  
Baoshan Huang ◽  
Xiang Shu ◽  
Hao Wu ◽  
Hongren Gong ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Damping Ratio ◽  
Shear Stiffness ◽  
Damping Properties ◽  
Railway Ballast ◽  
Loading Test ◽  
Interface Shear ◽  
Peak Shear Stress ◽  
Dilation Effect ◽  
Tire Derived Aggregate

The damping properties of railway ballast are critical to the safe operation of trains. This study aimed to improve the damping properties of railway ballast through the addition of tire-derived aggregate (TDA) and to evaluate the effect of TDA on other properties of ballast. The damping property and other mechanical properties of ballast mixed with different contents of TDA were tested utilizing a large direct shear test (DST) under static and cyclic loading conditions. The cyclic loading test was performed in accordance with ASTM D 7499, from which the resilient interface shear stiffness and damping ratio were obtained. The results showed that TDA significantly increased the damping ratio of railway ballast, but decreased the resilient interface shear stiffness. The stress-strain behavior of the ballast-TDA mixes was obtained from the static loading test, showing that TDA significantly decreased the peak shear stress and the dilation effect. According to the Mohr-Coulomb failure criterion, TDA also decreased the cohesion strength and the internal friction angle of the ballast. Based on the test results from this study, 5% rubber is recommended for use in railway ballast.

scholarly journals The Role of In Situ Stress in Organizing Flow Pathways in Natural Fracture Networks at the Percolation Threshold

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Chuanyin Jiang ◽  
Xiaoguang Wang ◽  
Zhixue Sun ◽  
Qinghua Lei
Keyword(s):  
Fluid Flow ◽  
Percolation Threshold ◽  
Fractured Reservoirs ◽  
Fracture Network ◽  
In Situ Stress ◽  
Natural Fracture ◽  
Fracture Aperture ◽  
Dilation Effect ◽  
Stress Dependent

We investigated the effect of in situ stresses on fluid flow in a natural fracture network. The fracture network model is based on an actual critically connected (i.e., close to the percolation threshold) fracture pattern mapped from a field outcrop. We derive stress-dependent fracture aperture fields using a hybrid finite-discrete element method. We analyze the changes of aperture distribution and fluid flow field with variations of in situ stress orientation and magnitude. Our simulations show that an isotropic stress loading tends to reduce fracture apertures and suppress fluid flow, resulting in a decrease of equivalent permeability of the fractured rock. Anisotropic stresses may cause a significant amount of sliding of fracture walls accompanied with shear-induced dilation along some preferentially oriented fractures, resulting in enhanced flow heterogeneity and channelization. When the differential stress is further elevated, fracture propagation becomes prevailing and creates some new flow paths via linking preexisting natural fractures, which attempts to increase the bulk permeability but attenuates the flow channelization. Comparing to the shear-induced dilation effect, it appears that the propagation of new cracks leads to a more prominent permeability enhancement for the natural fracture system. The results have particularly important implications for predicting the hydraulic responses of fractured rocks to in situ stress fields and may provide useful guidance for the strategy design of geofluid production from naturally fractured reservoirs.

Inhibition of pacing-induced coronary dilation by aminophylline

1975 ◽  
Vol 9 (4) ◽  
pp. 532-537 ◽  
Author(s):  
J. LAMMERANT ◽  
I. BECSEI
Keyword(s):  
Coronary Dilation

scholarly journals Nitroglycerin-induced coronary dilation is impaired early after cardiac transplantation

1991 ◽  
Vol 17 (2) ◽  
pp. A309 ◽  
Author(s):  
Andrew L. McGinn ◽  
Betsy V. Christensen ◽  
Susan M. Meyer ◽  
Ada Simon ◽  
Spencer H. Kubo ◽  
...  
Keyword(s):  
Cardiac Transplantation ◽  
Coronary Dilation

scholarly journals Mössbauer experiments in a rotating system and physical interpretation of their results

2021 ◽  
pp. 34-43
Author(s):  
Alexander L. Kholmetskii ◽  
Tolga Yarman ◽  
Ozan Yarman ◽  
Metin Arik
Keyword(s):  
Energy Shift ◽  
Special Theory ◽  
Relativistic Energy ◽  
Theory Of Relativity ◽  
Rotating System ◽  
Rotating Systems ◽  
Extra Energy ◽  
Quantum Mechanical Description ◽  
Dilation Effect ◽  
The Moment

We discuss the results of modern Mössbauer experiments in a rotating system, which show the presence of an extra energy shift between the emitted and absorbed resonant radiation in addition to the relativistic energy shift of the resonant lines due to the time dilation effect in the co-rotating source and absorber with different radial coordinates. We analyse the available attempts to explain the origin of the extra energy shift, which include some extensions of special theory of relativity with hypothesis about the existence of limited acceleration in nature, with hypothesis about a so-called «time-dependent Doppler effect», as well as in the framework of the general theory of relativity under re-analysis of the metric effects in the rotating system, which is focused to the problem of correct synchronisation of clocks in a rotating system with a laboratory clock. We show that all such attempts remain unsuccessful until the moment, and we indicate possible ways of solving this problem, which should combine metric effects in rotating systems with quantum mechanical description of resonant nuclei confined in crystal cells.

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