Previously, we have shown that the phosphoinositide-3-kinase (PI3K) mediated acute (24 h) post-conditioning neuroprotection induced by propofol. We also found that propofol post-conditioning produced long term neuroprotection and inhibited the internalization of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluR2 subunit up to 28 days post middle cerebral artery occlusion (MCAO). However, the relationship between PI3K with AMPA receptor GluR2 subunit trafficking in propofol post-conditioning has never been explored. Here we showed that propofol post-conditioning promoted the binding of PI3K to the C-terminal of AMPA receptor GluR2 subunit and formed a complex within 1 day after transient MCAO. Interestingly, the enhanced activity of PI3K was observed in the hippocampus of post-conditioning rats at day 1 post ischemia, whereas the decrease of AMPA receptor GluR2 subunit internalization was found up to 28 days in the same group. Administration of PI3K selective antagonist wortmannin inhibited the improvement of spatial learning memory and the increase of neurogenesis in the dentate gyrus up to 28 days post ischemia. It also reversed the inhibition of AMPA receptor GluR2 internalization induced by propofol post-conditioning. Together, our data indicated the critical role of PI3K in regulating the long term neuroprotection induced by propofol post-conditioning. Moreover, this role was established by first day activation of PI3K and formation of PI3K-AMPA receptor GluR2 complex, thus stabilized the structure of postsnaptic AMPA receptor and inhibited the internalization of GluR2 subunit during the early stage of propofol post-conditioning.

BackgroundThe Guardian Laryngeal Mask Airway (G-LMA) is a new silicone-based single-use extraglottic device with the drainage port and a cuff pilot valve with pressure indicator. The aim of this study is to compare the clinical performance of this laryngeal mask airway with ProSeal laryngeal mask airway (P-LMA).MethodsIn this prospective randomized study, we included adult patients with ASA grading I and II scheduled for elective surgery requiring supine position under total intravenous anesthesia. The patients were randomly allocated to two groups, 40 in each. G-LMA and P-LMA were used in groups G and P respectively. The cuff of each device was air inflated to 60 cmH2O. The primary outcome was to compare the airway sealing pressure and the secondary outcome was to compare the efficacy and safety of these two devices with respect to insertion success, insertion time, ease of insertion, volume of air for cuff inflation to 60 cmH2O, intracuff pressure measurement, gastric tube insertion attempt, gastric tube insertion time, Fiberoptic laryngeal view, and postoperative pharyngolaryngeal morbidity.ResultsThe airway sealing pressure at 60cmH2O cuff pressure was significantly greater in G-LMA than P-LMA (p = 0.04).The first successful attempt of both groups were comparable (p = 1.000). Insertion time was significantly shorter in G-LMA than P-LMA (p < 0.0001). The first successful attempt for the gastric tube insertion in both groups was comparable (p = 0.431). Gastric tube insertion time was less in G-LMA than in P-LMA (p < 0.0001). The volume of air for cuff inflation to 60 cmH2O was more in G-LMA than in P-LMA (<0.0001). The intracuff pressure measurement at 30, 60, 90 and 120 minutes were comparable (p = 0.823, 0.182, 0.870, 0.658).We did not find differences in ease of insertion (p = 0.60); Fiber-optic positions of airway devices were comparable (p = 0.83). In addition, blood staining (p = 1.00), sore throat and dysphagia at 1, 2 and 24 hour (p = 1.00) were comparable in both groups.ConclusionThe Guardian laryngeal mask airway was associated with high airway sealing pressure with a quicker insertion of the device as well as gastric tube.Trial registrationClinical Trial.gov Identifier: NCT02063516. Date: June 2013Electronic supplementary materialThe online version of this article (doi:10.1186/s12871-015-0039-3) contains supplementary material, which is available to authorized users.

High light intensity as one of the stresses could lead to generation of large amounts of reactive oxygen species (ROS) in plants, resulting in severe plant growth retardation. The photorespiration metabolism plays an important role in producing and removing a variety of ROS, maintaining the dynamic balance of the redox reaction, and preventing photoinhibition. Arabidopsis hydroxypyruvate reductase 1 (HPR1) is a primary metabolic enzyme in the photorespiration cycle. However, the role of HPR1 in plants response to high light is not clear. Here, we found that the expression of HPR1 could be induced by high light intensity. The growth and photosynthetic capacity of hpr1 mutants are seriously affected under high light intensity. The absence of HPR1 suppresses the rates of photorepair of Photosystem II (PSII), aggravates the production of ROS, and accelerates photorespiration rates. Moreover, the activity of ROS scavenging enzymes in the hpr1 mutants is significantly higher. These results indicate that HPR1 is involved in plant response to high light intensity and is essential for maintaining the dynamic balance of ROS and photorespiration.

PurposeSince One Belt One Road (OBOR) was proposed, Singaporean sides have reacted differently. Based on the case of Zaobao, the authors develop the theoretical frame including international relations, agenda setting and media framing, analyzing the construction of textual materials on OBOR and its influencing factors.Design/methodology/approachIn this sense, this paper attempts to use Zaobao's texts on OBOR from 2015 to 2017 as textual materials, by using the discourse analysis method and combining the theories of international relations, agenda setting and media framing, to explore the following two relevant questions: How does the mainstream Chinese media of Singapore construct OBOR issue? What factors influence this kind of construction?FindingsThe study finds that agendas setting on OBOR are diversified in the purpose of supporting official position and meeting audiences' expectations, which are constrained by the factors such as international situations, regional strategies, national interests and domestic politics. The authors learn more details about hidden and vague thoughts on OBOR from all sides in Singapore through this discourse analysis.Originality/valueIn summary, the academic community has a certain foundation for the study of the cognition of the “Belt and Road” initiative. However, compared with the other countries' research on the Belt and Road cognition, the research on Singapore is insufficient. Singapore is an important hub for the 21st Century Maritime Silk Road. At the same time, as a leader of Association of Southeast Asian Nations (ASEAN), it has a strong appeal and influence in other ASEAN countries. It has also played a pivotal role in building the “Belt and Road”. However, the “Belt and Road” initiative has been proposed and implemented for five years. The research on Singapore's cognition and reaction of the “Belt and Road” initiative is still insufficient. Therefore, an in-depth study of Singapore's cognition of the ‘Belt and Road” initiative has significant academic and applied value. This paper attempts to explore the construction of the “One Belt, One Road” initiative by Singapore's official media to make up for the shortcomings of existing research.