Effect of dexmedetomidine against liver ischemia-reperfusion injury in rats by reducing endoplasmic reticulum stress

Objective:To investigate the effect of dexmedetomidine against liver ischemia-reperfusion injury in rats by reducing endoplasmic reticulum stress.Methods: A total of 24 adult male Sprague-Dawley rats were randomly divided into sham operation group (6 rats, Sham group), liver ischemia-reperfusion injury group (6 rats, I/R group), and liver ischemia-reperfusion injury +dexmedetomidine pretreatment group (6 rats, I/R +Dex pretreatment group) (25μg/kg intraperitoneally 30 min before ischemia), and liver ischemia-reperfusion injury +dexmedetomidine post-treatment group (6 rats, I/R +Dex post-treatment group) (25 μg/kg intraperitoneally 30 min after reperfusion). Hepatic ischemia-reperfusion injury model was performed by after clamping the hepatic hilum for 30 min and reperfusion for 6 h. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured by automatic biochemical analyzer. Malondialdehyde (MDA) and superoxide dismutase (SOD) activity were detected by enzyme-linked immunosorbent assay (ELISA). The pathological changes of each group were observed by HE staining. The expression of endoplasmic reticulum stress (P-PERK, P-IRE1 , CHOP) were detected by Western blot.Results: Compared with the Sham group, the serum levels of ALT and AST were significantly higher in the I/R group, compared with the I/R group, the serum ALT and AST in I/R+Dex pretreatment group and the I/R+Dex post-treatment group were significantly reduced;Compared with the Sham group, MDA activity in the liver tissue of the I/R group was significantly increased, while the SOD activity was significantly decreased, and the pathological score of the liver tissue was significantly increased;Compared with the I/R group, MDA activity and liver histopathology scores in I/R+Dex pretreatment group and the I/R+Dex post-treatment group were decreased, while SOD activity increased;The expression of P-PERK, P-IRE1 , CHOP in the I/R group were significantly higher than that in the Sham group, while the expression of the above indicators were reduced in I/R+Dex pretreatment group and the I/R+Dex post-treatment group. Conclusion: Dexmedetomidine can significantly attenuated liver ischemia-reperfusion injury in rats, which may be related to the reduction of endoplasmic reticulum stress.

Deep original information preservation by applying in-situ film formation technology during coring

Accurately obtaining the original information of an in-situ rock via coring is a significant guiding step for exploring and developing deep oil and gas resources.It is difficult for traditional coring technology and equipment to preserve the original information in deep rocks.This study develops a technology for insitu substance-preserved(ISP),moisture-preserved(IMP),and light-preserved(ILP)coring.This technology stores the original information in real time by forming a solid sealing film on the in-situ sample during coring.This study designed the ISP-IMP-ILP-Coring process and tool.In addition,an ISP-IMP-ILPCoring process simulation system was developed.The effects of temperature,pressure,and film thickness on the quality of the in-situ film were investigated by performing in-situ film-forming simulation experiments.A solid sealing film with a thickness of 2-3 mm can be formed;it completely covers the core sample and has uniform thickness.The film maintains good ISP-IMP-ILP properties and can protect the core sample in the in-situ environment steadily.This study verifies the feasibility of“film formation during coring”technology and provides strong support for the engineering application of ISP-IMP-ILPCoring technology.

Kinetic Alfvén waves in a deuterium-tritium fusion plasma with slowing-down distributed α-particles

The dispersion relation and damping rate of kinetic Alfvén waves(KAWs) in a deuterium-tritium fusion plasma with slowing-down distributed α-particles are investigated using the kinetic theory. The variations of wave frequency and damping rate with respect to the α concentration(n_(α)/n_(e)) and perpendicular wave number(k_(⊥)) are studied from a numerical way. The results show that the fluctuation of α concentration slightly affects the frequency and damping rate of KAWs at low n_(α)/n_(e). In addition, the frequency and the damping rate increase as the k_(⊥) and the background temperature Te increase. For comparison, the calculations are performed also in the case of α-particles following an equivalent Maxwellian distribution. For a given k_(⊥), the value of the frequency obtained in the slowing-down distribution case is smaller than that obtained in the Maxwellian distribution case. Conversely, the value of the damping rate obtained in the slowing-down distribution case is slightly larger than that obtained in the Maxwellian distribution case.