ABSTRACT
In condensed-matter systems, electrons are subjected to two different interactions under certain conditions. Even if both interactions are weak, it is difficult to perform perturbative calculations due to the complexity caused by the interplay of two interactions. When one or two interactions are strong, ordinary perturbation theory may become invalid. Here we consider undoped graphene as an example and provide a non-perturbative quantum-field-theoretic analysis of the interplay of electron-phonon interaction and Coulomb interaction. We treat these two interactions on an equal footing and derive the exact Dyson-Schwinger (DS) integral equation of the full Dirac-fermion propagator. This equation depends on several complicated correlation functions and thus is difficult to handle. Fortunately, we find that these correlation functions obey a number of exact identities, which allows us to prove that the DS equation of full fermion propagator is self-closed. After solving this self-closed equation, we obtain the renormalized fermion velocity and show that its energy (momentum) dependence of renormalized fermion velocity is dominantly determined by the electron-phonon (Coulomb) interaction. In particular, the renormalized velocity exhibits a logarithmic momentum dependence and a non-monotonic energy dependence.
ABSTRACT
Transient electroluminescent measurement system is used to study the inside charge behavior of prepared organic light-emitting diodes (OLEDs) in this article. Two rectangular pulses with a fixed time interval are supplied on the device. We can analyze the inside charge storage and the emitting process by measuring the transient EL and transient current of the device. OLEDs based on the m-MTDATAâ¶3TPYMB (1â¶1) system was prepared. We found that the stable EL intensity increase when the second pulse is supplied. And the increment reduced with the increased current. We also find the electroluminescent under the second pulse decayed faster than that of the first pulse. This is because of the quenching due to the polaron-exciton effect (TPQ) is more serious in the emitting layer under the second pulse.
ABSTRACT
The aim of this study was to explore the "intensity-response" relationship in local moxibustion-like stimuli- (LMS-) modulated gastric motility and its underlying receptor mechanism. Based on the thermal pain threshold (43°C), 41°C, 43°C, and 45°C LMS were separately applied to ST36 or CV12 for 180 s among ASIC3 knockout (ASIC3-/-) mice, TRPV1 knockout (TRPV1-/-) mice, and their homologous wild-type C57BL/6 mice (n = 8 in each group). Gastric motility was continuously measured by an intrapyloric balloon, and the amplitude, integral, and frequency of gastric motility during LMS were compared with those of initial activities. We found that both 43°C and 45°C LMS at ST36 induced significantly facilitated effect of gastric motility (P < 0.05), while LMS at CV12 induced inhibited effects (P < 0.05). 41°C LMS had no significant impact on gastric motility. Compared with C57BL/6 mice, the facilitatory effect at ST36 and inhibitive effect of LMS at CV12 were decreased significantly in TRPV1-/- mice (P < 0.05; P < 0.01) but not changed markedly in ASIC3-/- mice (P > 0.05). These results suggest that there existed an "intensity-response" relationship between temperature in LMS and its effects on gastric motility. TRPV1 receptor played a crucial role in the LMS-modulated gastric motility.
ABSTRACT
The aim of this study was to reveal the somatosensory nerve fibers mediated generation of De-qi in manual acupuncture stimuli (MAS) and local moxibustion-like stimuli (LMS). The effects of strong and slight MAS, as well as 41°C, 43°C, and 45°C LMS at ST36 and CV12 on gastric motility were observed in rats. Gastric motility was continuously measured by an intrapyloric balloon, and the average amplitude, integral, and frequency of gastric motility during LMS were compared with those of background activity. Gastric motility was facilitated by MAS and LMS at ST36 and inhibited at CV12. The modulatory effects induced by strong MA with potent De-qi (needle grasp feeling) were markedly higher than those by slight MA with mild De-qi sensation (P < 0.05). The nociceptive 43°C and 45°C LMS, rather than nonnociceptive 41°C LMS, produced significant regulatory effects on gastric motility. Based on the afferent fibers activated in the present study, these results support the hypothesis that A δ - and C-afferent fibers were more likely to be involved in the generation of De-qi sensation.
ABSTRACT
This study focused on the effects of laser acupuncture (LA) and manual acupuncture (MA) at different acupoints on gastric motility and heart rate variability (HRV) simultaneously to elucidate the site specific effects of acupoints and the correlation between changes of gastric motility and low frequency/high frequency (LF/HF) ratio. Gastric motility and HRV were recorded before and during MA or LA. Stimulating PC-6 or ST-36 significantly enhanced gastric motility, while BL-21 caused no changes. In contrast, MA or LA at CV-12 significantly suppressed gastric motility. Stimulating PC-6 or ST-36 significantly increased heart rate (HR), while CV-12 or BL-21 induced no significant changes of HR. Stimulating PC-6 significantly increased LF/HF, while ST-36, CV-12, or BL-21 induced no significant effects. These results indicated that there was acupoint specificity in the effects of acupuncture on gastric motility and HRV. The stimulatory effect of MA and LA at PC-6 and ST-36 on HR was associated with sympathetic activity. The stimulatory effect of MA or LA at PC-6 or ST-36 on gastric motility was associated with vagal activity. Laser needle can be used as an alternative stimulation therapy.
ABSTRACT
The purpose of this study was to evaluate the influence of the duration of interstitial laser acupuncture therapy effects on neurovegetative and neurobioelectrical parameters like heart rate (HR), heart rate variability (HRV), and electroencephalogram (EEG). We investigated 6 male Sprague-Dawley rats. They underwent 10 min, 20 min, and 30 min interstitial laser acupuncture (in randomized order, with a break of at least 30 min between the different measurement conditions) at the acupoint Neiguan. HR changed significantly only during 20 min red laser stimulation, whereas 10 and 30 min stimulation did not induce significant changes. HRV did not change significantly during any of the different durations; however, an increase was found during 20 min irradiation. Neither the LF/HF ratio of HRV nor the integrated EEG showed significant changes. In this study, it could be experimentally proved that some effects of laser acupuncture are time dependent, and therefore the dosage, as well known from theory, also depends on the time factor. We could especially demonstrate that different treatment times lead to different effects on neurovegetative and neurobioelectrical parameters. Further studies are needed to verify or refute these results.
ABSTRACT
OBJECTIVE: To observe the effect of electroacupuncture (EA) and moxibustion-like thermal stimulation with different temperatures at "Zusanli" (ST 36) on pain reactions in transient receptor potential vanilloid type 1 knock-out (TRPV 1 -/-) mice so as to study its mechanisms underlying analgesia. METHODS: Ten C 57 BL/6 mice and 10 TRPV 1 -/- mice were respectively divided into control and TRPV 1 -/- groups. EA (0.3 mA, 1.0 mA, 3.0 mA) or thermal water-bath (38 degrees C, 43 degrees C, 46 degrees C) stimulation was applied to the right ST 36 for 20 min and 10 min, respectively. Mechanical and thermal pain thresholds of the bilateral paws were detected before and immediately after stimulation, and 5 min after EA stimulation at 0.3 mA, 3.0 mA and thermal water-bath stimulation at 38 degrees C, 46 degrees C, separately. RESULTS: (1) The thermal threshold was significantly higher in TRPV 1 -/- mice than in C 57 BL/6 mice (P < 0.001). (2) In C 57 BL/6 mice, both homolateral and contralateral mechanical and thermal pain thresholds were significantly increased following 1.0 mA, 3.0 mA EA, and 43 degrees C and 46 degrees C thermal stimulation of the right Zusanli (ST 36) (P < 0.05, P < 0.01, P < 0.001); while only homolateral mechanical and thermal pain thresholds were increased after 0.3 mA EA and 38 degrees C thermal stimulation of ST36 (P < 0.05, P < 0.01). In TRPV 1 -/- mice group, both homolateral and contralateral mechanical and thermal pain thresholds were significantly increased by 3.0 mA EA stimulation of ST 36 (P < 0.05, P < 0.01). Bilateral mechanical thresholds and homolateral thermal threshold were significantly increased by 1.0 mA EA stimulation of ST 36 (P < 0.05, P < 0.01), while only homolateral mechanical and thermal pain thresholds were increased by 0.3 mA EA, and 43 degrees C and 46 degrees C thermal stimulation (P < 0.05, P < 0.01). Additionally, only the homolateral mechanical threshold was increased by 38 degrees C thermal stimulation (P < 0.05). (3) The mechanical and thermal pain thresholds of the bilateral limbs were increased to some extent in TRPV 1 -/- mice compared with those of C 57 BL/6 mice following EA and thermal stimulation of the right ST 36. (4) Five minutes after 0.3 mA, 3.0 mA EA and 38 degrees C, 46 degrees C thermal water-bath stimulation, both mechanical and thermal pain thresholds recovered to their baseline levels in both TRPV 1 -/- and C 57 BL/6 mice. CONCLUSION: Both EA and thermal stimulation of the right ST 36 can raise mechanical and thermal pain thresholds in TRPV 1 -/- and C 57 BL/6 mice, but needing a stronger stimulation in TRPV 1 -/- mice, suggesting an involvement of TRPV 1 receptors in analgesia.
