Observation of the spin-Hall effect in Pt/GaAs by circular polarized photoconductivity.

Electrically generated spin accumulation due to the spin Hall effect of Pt/GaAs is detected by circular polarized photoconductivity (CPPC), which shows electron spins with different polarizations accumulated around opposite sample boundaries. An optical absorption model incorporating spin is used to explain these features. The detailed analysis of the observed degree of circular polarization of the photocurrent strongly suggests that Pt and GaAs have the same spin accumulation length in the Pt/GaAs heterostructure.

Current-Induced Spin Photocurrent in GaAs at Room Temperature.

Circularly polarized photocurrent, observed in p-doped bulk GaAs, varies nonlinearly with the applied bias voltage at room temperature. It has been explored that this phenomenon arises from the current-induced spin polarization in GaAs. In addition, we found that the current-induced spin polarization direction of p-doped bulk GaAs grown in the (001) direction lies in the sample plane and is perpendicular to the applied electric field, which is the same as that in GaAs quantum well. This research indicates that circularly polarized photocurrent is a new optical approach to investigate the current-induced spin polarization at room temperature.

Anomalous circular photogalvanic effect in p-GaAs.

The anomalous circular photogalvanic effect (ACPGE) is observed in p-GaAs with a thickness of 2 µm at room temperature, in which circularly polarized light is used to inject spin-polarized carriers and the spin diffusion can generate a macroscopic detectable charge current due to the inverse spin Hall effect. The normalized ACPGE signals show first increasing and then decreasing with increasing the doping concentration. The role of the doping impurities is discussed by both extrinsic and intrinsic models, and both can well explain the variation of ACPGE with the doping concentration.

Distinguishing the inverse spin Hall effect photocurrent of electrons and holes by comparing to the classical Hall effect.

The photo-excited electrons and holes move in the same direction in the diffusion and in the opposite direction in the drift under an electric field. Therefore, the contribution to the inverse spin Hall current of photo-excited electrons and holes in the diffusion regime is different to that in the drift regime under electric field. By comparing the classical Hall effect with the inverse spin Hall effect in both diffusion and drift regime, we develop an optical method to distinguish the contributions of electrons and holes in the inverse spin Hall effect. It is found that the contribution of the inverse spin Hall effect of electrons and holes in an InGaAs/AlGaAs un-doped multiple quantum well is approximately equal at room temperature.

Exercise combined with administration of adipose-derived stem cells ameliorates neuropathic pain after spinal cord injury.

Experimental studies have shown that exercise and human adipose-derived stem cells (ADSCs) play positive roles in spinal cord injury (SCI). However, whether ADSCs and/or exercise have a positive effect on SCI-induced neuropathic pain is still unclear. Thus, there is a need to explore the effects of exercise combined with administration of ADSCs on neuropathic pain after SCI. In this study, a thoracic 11 (T11) SCI contusion model was established in adult C57BL/6 mice. Exercise was initiated from 7 days post-injury and continued to 28 days post-injury, and approximately 1 × 105 ADSCs were transplanted into the T11 spinal cord lesion site immediately after SCI. Motor function and neuropathic pain-related behaviors were assessed weekly using the Basso Mouse Scale, von Frey filament test, Hargreaves method, and cold plate test. Histological studies (Eriochrome cyanine staining and immunohistochemistry) were performed at the end of the experiment (28 days post-injury). Exercise combined with administration of ADSCs partially improved early motor function (7, 14, and 21 days post-injury), mechanical allodynia, mechanical hypoalgesia, thermal hyperalgesia, and thermal hypoalgesia. Administration of ADSCs reduced white and gray matter loss at the lesion site. In addition, fewer microglia and astrocytes (as identified by expression of ionized calcium-binding adapter molecule 1 and glial fibrillary acidic protein, respectively) were present in the lumbar dorsal horn in the SCI + ADSCs and SCI + exercise + ADSCs groups compared with the sham group. Our findings suggest that exercise combined with administration of ADSCs is beneficial for the early recovery of motor function and could partially ameliorate SCI-induced neuropathic pain.

Meta-Analysis on the Anesthetic Effects of Remifentanil plus Dexmedetomidine versus Remifentanil Alone in Cardiac Surgery.

In this study, we performed a meta-analysis to investigate the anesthesia effects of remifentanil plus dexmedetomidine versus remifentanil alone in cardiac surgery. Literature search was performed on PubMed, Web of Science, Embase, China Knowledge Infrastructure, Wanfang Data, and other databases for relevant literature published in English or Chinese before October 2021. A total of 17 studies, consisting of 1350 patients, were included in this study. Of these, 10 studies showed that remifentanil plus dexmedetomidine had a good anesthesia effect in cardiac surgery (OR = 3.61, 95% CI: 1.73, 7.52, P < 0.001), and 8 studies showed that the Ramsay score test of anesthesia (SMD = 0.88; 95% CI: -0.77, 2.53; P < 0.001) in the experimental group was better than that in the control group. In addition, changes in the hemodynamic heart rate (SMD = -0.74; 95% CI: -1.41, -0.07; P < 0.001) and mean arterial pressure (SMD = -0.18; 95% CI: -0.72, 0.36; P < 0.001) of the two groups of anesthesia were counted in 17 studies, which also showed that the anesthesia effect of remifentanil plus dexmedetomidine was good. Thus, remifentanil plus dexmedetomidine may be a more promising option for cardiac surgery anesthesia than remifentanil alone.

Neurogenic hypothesis of cardiac ischemic pain.

Coronary heart disease is the major cause of death worldwide and is affecting millions of people in both developed and developing countries. Patients with myocardial ischemia typically experience chest pain (angina pectoris). Traditional viewpoint of ischemic cardiac pain might be related to "mechanical hypothesis" in early time and "chemical hypothesis" in modern time. However, perception of cardiac ischemic pain is still not well understood. The previous studies suggested that neurogenic mechanisms including neurogenic inflammation and neurogenic activity might participate in the pathophysiological processes following myocardial ischemia. Therefore, we raise "neurogenic hypothesis", that is, neurogenic mechanisms might play a pivotal role in myocardial ischemic injury. Analgesia intervention, rivalry of neurogenic inflammatory reactions and electrostimulatory therapy, etc. could not only relieve the pain symptoms, but also block nociception of body and neurogenic reaction induced by ischemia. Thereby ischemic myocardial injury would be extenuated and myocardial protection be produced. Attempts to confirm this hypothesis may lead to new theory of pathophysiologic mechanisms and provide potential intervention strategy for cardiac ischemic pain.

[Effect of different doses of atorvastatin on adhesion molecules of the patients undergoing percutaneous coronary intervention].

OBJECTIVE: To determine the effect of different doses of atorvastatin on the serum soluble intercellular adhesion molecules-1 (sICAM-1) in patients undergoing percutaneous coronary intervention (PCI). METHODS: The study consisted of 38 patients with unstable angina and 10 patients with old infarction who underwent elected PCI for stenotic lesions of the coronary artery. Patients were randomly assigned to either aggressive group or conventional one. After PCI the patients took atorvastatin 20 mg per day or 10 mg per day. Blood lipid profile was examined before, and 3 months after the PCI. SICAM-1 was examined before the PCI, 48 hours and 3 months after the PCI. RESULTS: The total cholesterol and LDL-Cholesterol 3 months after the PCI in the 2 groups were lower than those before the PCI (P<0.01). The aggressive group showed greater reduction in concentrations of TC and LDL-C than the conventional group (P<0.01). The changes in concentrations of HDL-C between pre-PCI and 3 months after the PCI and TG were not obvious (P>0.05). sICAM-1 in the 2 groups 48 hours after the PCI significantly higher than that before the PCI (P<0.01). But sICAM-1 in the 2 groups 3 months after the PCI significantly lower than that before the PCI (P<0.01 or P<0.05). The aggressive group showed greater reduction than the conventional group (P<0.01). TC and LDL-C were positively correlated with sICAM-1(r=0.2413, r=0.2691, all P<0.05). CONCLUSION: Atorvastatin 20 mg per day reduces TC, LDL-C, and sICAM-1 to a greater extent than atorvastatin 10 mg per day. The effect on sICAM-1 is partly related to reduce lipid profile.

[Effect of acupuncture intervention on gastrointestinal motility and liver pathological changes in cirrhotic rats].

OBJECTIVE: To observe the effect of acupuncture intervention on gastrointestinal motility and liver pathologic changes in cirrhotic rats so as to reveal its underlying mechanisms in improving cirrhosis. METHODS: Cirrhotic model was established by subcutaneous injection of CCL 4-olive oil (3-5 mL/kg), and intake of high fat diet mixed with 15% ethanol aqueous. Forty SD rats were randomly divided into control, model, acupuncture and medication groups (n = 10 in each group). For rats of the acupuncture group, EA was applied to bilateral "Zusanli" (ST 36), "Sanyinjiao" (SP 6) and "Taichong" (LR 3) for 15 min, once daily for 14 days. Rats of the medication group were treated by gavage of Domperidone liquid (100 mg/100 mL, 0.6 mL/100 g) once daily for 14 days. The food-intake state, propulsive rate of small intestine, liver index, portal vein diameter were recorded or measured, and the liver pathological changes were observed under microscope after H. E. and reticular fibers staining. RESULTS: In the model group, the food-intake amount and propulsive rate of small intestine were significantly reduced (P < 0.05), the liver index and portal vein diameter were considerably increased (P < 0.05) when compared with those of the control group. While in comparison with the model group, the food-intake amount and propulsive rate of the small intestine were apparently increased in both acupuncture and medication groups (P < 0.05), while the liver index and portal vein diameter were obviously down-regulated in the acupuncture group (P < 0.05), not in the medication group (P > 0.05). H.E. and reticular fibers stain showed that CCL 4-induced changes of the liver tissue such as cirrhosis, fibroplasias, pseudo-lobulation, fibroplasias, diffusive inflammatory cell infiltration, etc. were relatively milder in the acupuncture group, rather than in the medication group. CONCLUSION: Electroacupuncture therapy has a positive effect in improving gastrointestinal motility and may be favorable to relieve hepatic pathological changes in liver cirrhosis rats.

Long-time course of protease-activated receptor-1 expression after intracerebral hemorrhage in rats.

Thrombin plays an important role in brain injuries associated with intracerebral hemorrhage (ICH). The protease-activated receptor (PAR)-1 is responsible for the vast majority of the thrombin's cellular activation functions. We tested the hypothesis that thrombin-induced brain damage after ICH, at least in part, is mediated by PAR-1. We report that there are significant differences between PAR-1 positive cell number and PAR-1 mRNA absorbance ratio between ICH model group (at 6h, 24h, 3 d, 7 d and 14 d) and normal group (P<0.05). These results suggest that the long-time course of PAR-1 expression may be partly involved in the mechanism of thrombin-induced brain damage after ICH.