BACKGROUND: Somatosensory evoked potential (SEP) has become a method with higher sensitivity and specificity than electroencephalogram in detecting the brain function and the region, range and degree of ischemia. H...BACKGROUND: Somatosensory evoked potential (SEP) has become a method with higher sensitivity and specificity than electroencephalogram in detecting the brain function and the region, range and degree of ischemia. However, the effects of ligustrazine on SEP is still not clear. OBJECTIVE : To study the protective effects of ligustrazini injection on cerebral ischemia-reperfusion injury.DESIGN: Auto-control study, random grouping.SETTING: Qilu Hospital of Shandong University.MATERIALS: The experiment was completed in the Cerebral Functional Room of Qilu Hospital Affiliated to Shandong University from March 2002 to June 2004. A totally of 24 healthy Harbin rabbits were randomly divided into blank control group (n=8), model control group (n=8) and ligustrazine treatment group (n=8). Hydrochloric ligustrazine injection, 40 mg/2 mL each ampoule, was provided by the Third Pharmaceutical Factory of Beijing (certification: 93035236273). The main component was hydrochloric ligustrazine and the chemical name was 2, 3, 5, 6-tetramethyl pyrazine hydrochloride. METHODS:① Modeling method: The bilateral common carotid artery ligation was adopted to make the model. ② Index of cerebral functional lesion evaluated with SEP during ischemia-reperfusion: DISA 2000C neuromyoeletrometer provided by Dantec Electronics Ltd, Denmark was used to detect SEP. ③ Interventional process: Blank control group: The latencies and amplitudes of SEP were measured before injection with 1.5 mg/kg ligustrazine and at the points of 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after injection. Ligustrazine treatment group: Rabbits were injected with 1.5 mg/kg ligustrazine, and those of model control group were injected the same volume of saline. Thirty minutes later, the bilateral common carotid artery of the rabbits all had been ligated for 30 minutes, and then reperfused for 120 minutes. The latencies and amplitudes of SEP were measured before injection, before ligation, at the points of 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 30 minutes after ligation, and at the points of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after reperfusion.④ Evaluating criteria: Normal values of P-wave latencies and amplitudes were (19.34±3.18) ms and (4.55±1.43)μV. Average value before injection in blank control group and average values before injection, after injection and before ligation in ischemiareperfusion group were regarded as control criteria to evaluate changes of P-wave latencies and amplitudes after experiment. MAIN OUTCOME MEASURES: P-wave latencies and amplitudes of SEP in the three groups.RESULTS : A total of 24 rabbits were involved in the final analysis without any loss.① Blank control group: The P-wave latencies delayed markedly at each time point after injection. Compared with that before injection, there was a significant difference (P 〈 0.05-0.01). The P-wave amplitudes did not fluctuate noticeably all the time after injection, but significantly decreased when compared with those before injection (P 〈 0.05-0.01). ② Ischemia-reperfusion group: The P-wave latencies delayed and amplitudes decreased in the rabbits with cerebral ischemia-reperfusion at all points of time during cerebral ischemia-reperfusion, and there was significant difference when compared with the levels before ischemia (P 〈 0.05). When ligustrazine was injected, the latencies and amplitudes changed less, and as compared with the levels before ischemia, the difference was not significant (P〉 0.05).CONCLUSION:① Ligustrazine can inhibit P-wave latencies and amplitudes of SEP of normal rabbits.②Ligustrazine can improve P-wave latencies and amplitudes of SEP of rabbits with cerebral ischemia-reperfusion injury.展开更多
The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive...The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive index,effective normalized frequency and dispersion management solitons.It is shown that the dispersion in the cladding waveguide of the total internal reflective photonic crystal fiber is a positive dispersion,and the dispersion of its core waveguide is a negative dispersion.The method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of the total internal reflective photonic crystal fiber to be close to zero and the zero dispersion point to shift to the short wavelength region.展开更多
基金Technological Developing Plan of Science and Technology Bureau of Shandong Province, No. 032050116
文摘BACKGROUND: Somatosensory evoked potential (SEP) has become a method with higher sensitivity and specificity than electroencephalogram in detecting the brain function and the region, range and degree of ischemia. However, the effects of ligustrazine on SEP is still not clear. OBJECTIVE : To study the protective effects of ligustrazini injection on cerebral ischemia-reperfusion injury.DESIGN: Auto-control study, random grouping.SETTING: Qilu Hospital of Shandong University.MATERIALS: The experiment was completed in the Cerebral Functional Room of Qilu Hospital Affiliated to Shandong University from March 2002 to June 2004. A totally of 24 healthy Harbin rabbits were randomly divided into blank control group (n=8), model control group (n=8) and ligustrazine treatment group (n=8). Hydrochloric ligustrazine injection, 40 mg/2 mL each ampoule, was provided by the Third Pharmaceutical Factory of Beijing (certification: 93035236273). The main component was hydrochloric ligustrazine and the chemical name was 2, 3, 5, 6-tetramethyl pyrazine hydrochloride. METHODS:① Modeling method: The bilateral common carotid artery ligation was adopted to make the model. ② Index of cerebral functional lesion evaluated with SEP during ischemia-reperfusion: DISA 2000C neuromyoeletrometer provided by Dantec Electronics Ltd, Denmark was used to detect SEP. ③ Interventional process: Blank control group: The latencies and amplitudes of SEP were measured before injection with 1.5 mg/kg ligustrazine and at the points of 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after injection. Ligustrazine treatment group: Rabbits were injected with 1.5 mg/kg ligustrazine, and those of model control group were injected the same volume of saline. Thirty minutes later, the bilateral common carotid artery of the rabbits all had been ligated for 30 minutes, and then reperfused for 120 minutes. The latencies and amplitudes of SEP were measured before injection, before ligation, at the points of 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 30 minutes after ligation, and at the points of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after reperfusion.④ Evaluating criteria: Normal values of P-wave latencies and amplitudes were (19.34±3.18) ms and (4.55±1.43)μV. Average value before injection in blank control group and average values before injection, after injection and before ligation in ischemiareperfusion group were regarded as control criteria to evaluate changes of P-wave latencies and amplitudes after experiment. MAIN OUTCOME MEASURES: P-wave latencies and amplitudes of SEP in the three groups.RESULTS : A total of 24 rabbits were involved in the final analysis without any loss.① Blank control group: The P-wave latencies delayed markedly at each time point after injection. Compared with that before injection, there was a significant difference (P 〈 0.05-0.01). The P-wave amplitudes did not fluctuate noticeably all the time after injection, but significantly decreased when compared with those before injection (P 〈 0.05-0.01). ② Ischemia-reperfusion group: The P-wave latencies delayed and amplitudes decreased in the rabbits with cerebral ischemia-reperfusion at all points of time during cerebral ischemia-reperfusion, and there was significant difference when compared with the levels before ischemia (P 〈 0.05). When ligustrazine was injected, the latencies and amplitudes changed less, and as compared with the levels before ischemia, the difference was not significant (P〉 0.05).CONCLUSION:① Ligustrazine can inhibit P-wave latencies and amplitudes of SEP of normal rabbits.②Ligustrazine can improve P-wave latencies and amplitudes of SEP of rabbits with cerebral ischemia-reperfusion injury.
文摘The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive index,effective normalized frequency and dispersion management solitons.It is shown that the dispersion in the cladding waveguide of the total internal reflective photonic crystal fiber is a positive dispersion,and the dispersion of its core waveguide is a negative dispersion.The method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of the total internal reflective photonic crystal fiber to be close to zero and the zero dispersion point to shift to the short wavelength region.