ABSTRACT
OBJECTIVE@#To quantitatively investigate the effects of Ringer's solution with different concentrations of alcohol (1%～80%) on biphasic compound action potentials (AP) from frog sciatic nerve trunk, and their recoveries from alcohol effects.@*METHODS@#Individual segments of frog sciatic nerve trunk with a length of 6 to 8 cm were prepared. Ringer's solution with different concentrations of alcohol (0%, 1%, 2%, 4%, 8%, 16%, 32%, 48%, 64% and 80%) was applied onto the segment of the trunk between the stimulus and ground electrodes via an agent reservoir which was newly armed in a nerve trunk shielded chamber for 5 minutes. The nerve trunk was respectively electro-stimulated to generate the biphasic compound AP which was recorded using the experimental system of BL-420F. This was followed by 5 times washout plus 5 min administration with Ringer's solution before recovery recording of AP.@*RESULTS@#Compared to normal Ringer's solution, Ringer's solution with alcohol at ≤4% did not have dramatic impacts on the AP amplitude and conduction velocity, while Ringer's solution with alcohol at ≥8% there was significant decrease in these two parameters. Ringer's solution with alcohol at the conentrations of 16%, 32% and ≥48% could prevent a small proportion (30%), a large proportion (90%) and all (100%) of sciatic nerve trunks, respectively, from generating AP. Washout with normal Ringer's solution after alcohol application at the concentration of ≤32%, AP could totally recover to normal status. While alcohol at the concentration of 48%, 64% and 80%, the probabilities to regenerate APs were 90%, 40% and 0%, and the AP amplitudes were decreased to 60%, 36% and 0%, respectively. After washout, AP conduction velocity showed no difference with alcohol at the concentration of ≤8% when compared with that before washout, while it could not be recovered to normal under alcohol at ≥16%.@*CONCLUSION@#Ringer's solution with different concentrations of alcohol exerts different effects on biphasic compound AP amplitude and conduction velocity. Hopefully, our findings could be helpful for the alcoholic usage and its recovery from alcoholic damage.
Subject(s)
Animals , Action Potentials , Anura , Ethanol , Pharmacology , Ringer's Solution , Pharmacology , Sciatic NerveABSTRACT
Objective To merge the traditional magnetic imaging technology with emerging robotics and to create a new surgical model that replaces human eyes with robotic arms instead of manpower.Methods Structural compatibility analysis was executed with Monte Carlo method. According to the theory of magnetic field compatibility, the mechanical arm components were classified, the magnetic field compatibility of the manipulator was discussed, the key components of the manipulator were selected,and the finite element analysis was performed to verify its reliability.The positive and negative kinematics models of robotic arms were constructed by matrix transformation and robotics toolbox. The polynomial interpolation of five times was used to plan the trajectory of the end of the manipulator.Results The work space of the robot arm solved by Monte Carlo method was found to envelop completely the inner ring aperture of the NMR,and thus the spatial accessibility of the robot arm was verified.Finite element analysis proved that the structural strength of the manipulator was well-designed and the kinematics model of the manipulator was successfully constructed.The trajectory planning found that the joints rotated uniformly and the desired requirements were met.Conclusion The robot arm developed gains advantages in configuration and nuclear magnetic compatibility.
ABSTRACT
<p><b>OBJECTIVE</b>To establish a simple but effective method of laser scanning confocal microscopic imaging for Ca2+ oscillations of pancreatic acinar cells in adult mice.</p><p><b>METHODS</b>Pancreatic acinar cells from adult Kunming mice were isolated acutely with collagenase, and then loaded with fluo-4-AM, a Ca2+ indicator. A laser scanning confocal microscope armed with 488 nm laser was employed to record the dynamic fluorescent signals in-time and synchronously while acetylcholine (ACh) was added in the pancreatic acinar cells.</p><p><b>RESULTS</b>(1) The classic pancreatic acinar cell Ca2+ oscillations were induced by a certain concentration of ACh (100 nmol/L) successfully and steadily, which could be blocked by atropine completely. (2) Plasmic Ca2+ oscillations from different parts of one acinar cell were usually with different amplitudes and almost the same frequencies. But both of amplitudes and frequencies were different among different cells. (3) The acinar cell Ca2+ oscillations were induced by ACh in a concentration-dependent manner.</p><p><b>CONCLUSION</b>The laser scanning confocal microscopic imaging for adult mouse pancreatic acinar cell Ca2+ oscillations was established successfully. The features of being easy to use, direct to see lively, high efficiency and good flexibility make it a popular tool for researchers to choose.</p>
Subject(s)
Animals , Mice , Acinar Cells , Chemistry , Calcium , Calcium Signaling , Cells, Cultured , Microscopy, Confocal , Methods , Pancreas , Cell BiologyABSTRACT
<p><b>AIM</b>Fast 2-dimension scanning and line-scanning of confocal imaging were employed for measurement of cardiac Ca2+ transients, and the advantages and disadvantages about these two scannings were discussed.</p><p><b>METHODS</b>Single adult SD rat cardiac myocytes were made freshly and loaded with fluo4-AM. Intracellular Ca2+ was imaging by the LSMS10 META system. The Ca2+ transients were evoked by electrical field stimulation from an electronic stimulator which was triggered to work synchronically with the confocal imaging system.</p><p><b>RESULTS</b>Fast 2-dimension scanning showed the global Ca2+ signal clearly, which would be more helpful especially in monitoring a cell of Ca2+ overload or in other pathological conditions. And the images could be packaged into a vivid animation, which showed the process of Ca2+ transients and cell contraction visually and virtually. Line-scanning showed the Ca2+ transients in good temporal and spacial resolutions along the long axis of the cell. And the dynamic shortening of the cell length could be used for indicating the contraction of the cell. Data from line-scanning would be helpful for drawing some more exact conclusions.</p><p><b>CONCLUSION</b>In general, fast 2-dimension scanning and line-scanning could work reciprocally to show a more perfect picture of the intracellular Ca2+ transients in cardiac myocytes.</p>