Role of Notoginsenoside Rg1 in Improving Spatial Cognitive Ability and Lowering Phosphorylation Level of Tau Protein in AD Model Rats

[Objectives] To study the effects and mechanism of notoginsenoside Rg1 on the spatial learning and memory and phosphorylated tau protein in the AD( Alzheimer's Disease) model rat. [Methods]The AD model rat was replicated by injection of Aβ_(25-35) in the left lateral ventricles of SD rats. The low dose( 25 mg/kg),middle dose( 50 mg/kg) and high dose( 100 mg/kg) notoginsenoside Rg1 was used for intragastric administration,respectively,two times every day. After 4 weeks,the Morris water maze test was done to detect the learning and memory capacity,and the immunoblotting,immunohistochemical methods were used to detect the changes in the phosphorylation level and distribution of tau protein in hippocampus of the rats. [Results] After the intracerebroventricular injection of Aβ_(25-35),the learning and memory capacity of the model rats was significantly lower than the learning and memory capacity of the normal control rats. The immunoblotting test results showed that the phosphorylation level of tau protein threonine 231 site( Thr231) in hippocampus was significantly increased,and the nonphosphorylation level was significantly decreased. The morphological testing results showed that the phosphorylation level of tau protein Thr231 of AD model rats was increased markedly in region of DG,CA1 and CA3 of the hippocampus. The intervention of the middle dose notoginsenoside Rg1 could significantly improve the learning and memory capacity of the model rats in Morris water maze. The notoginsenoside Rg1 in three different doses could all reduce the phosphorylation level of tau protein Thr231 in the hippocampal DG,CA1,CA3 regions,and there were no significant differences among the three doses. [Conclusions]The notoginsenoside Rg1 could improve Aβ_(25-35)-induced spatial learning and memory impairment of the AD model rats,and decreased the phosphorylation level of tau protein in hippocampus.

Flow Instability of Molten GaAs in the Czochralski Configuration

The flow and heat transfer of molten GaAs under the interaction of buoyancy, Marangoni and crystal rotation in the Czochralski configuration are numerically studied by using a time-dependent and three-dimensional turbulent flow model for the first time. The transition from axisymmetric flow to non-axisymmetric flow and then returning to axisymmetric flow again with increasing centrifugal and coriolis forces by increasing the crystal rotation rate was numerically observed. The origin of the transition to non-axisymmetric flow has been proved to be baroclinic instability. Several important characteristics of baroclinic instability in the CZ GaAs melt have been predicted. These characteristics are found to be in agreement with experimental observations.

Gemcitabine and Doxorubicin Combination Enhance the Cytotoxic Effect to Pancreatic Cancer Cells BxPC3 and PANC1 through UMP/CMP Kinase 1

Background: Gemcitabine is a deoxycytidine analog, which is used as first-line agent for pancreatic cancer therapy, and its efficacy relied on its intracellular conversion to active triphosphate form. However, administration with gemcitabine still has limited effect on the overall survival of patients with pancreatic cancer. Objective: We aimed to study the combination effect of gemcitabine and doxorubicin to pancreatic cancer cells BxPC3 and PANC1, and unveil the mechanism. Methods: The study was performed in pancreatic cancer cells PANC1 and BxPC3, the contribution of UMP/CMP kinase 1 (CMPK1) to gemcitabine in PANC1 and BxPC3 cells was measured by transfection of CMPK1 plasmid or CMPK1 siRNA treatment to adjust the expression of CMPK1 in the cells;then analyzed the cell vitality and migration after treated with 1% IC50 of doxorubicin and gemcitabine or only with gemcitabine;the activity of CMPK1 and the effect of doxorubicin to the reaction was measured by HPLC assay in vitro;at last, docking analysis by computer was used to calculate the possible interaction sites of CMPK1 to DOX. Results: The sensitivity of PANC1 and BxPC3 cells to gemcitabine was improved when increasing the expression of CMPK1, and decreased when knockout CMPK1 by CMPK1 siRNA in BxPC3 cells;when combined with doxorubicin, the sensitivity of PANC1 and BxPC3 cells to gemcitabine also increased, and the cells migration reduced;we further found out that by adding 10 μM doxorubicin, the catalyzing activity of CMPK1 elevated about 2 times in vitro;the docking result showed that the association of CMPK1 to DOX was mainly by hydrogen bond and ionic interaction. Conclusion: CMPK1 can catalyze gemcitabine to its active form within the cells so that the sensitivity of the cells to gemcitabine elevated, and doxorubicin may enhance the cytotoxic effect to pancreatic cancer by up-regulate the activity of CMPK1, the combination of these deoxycytidine analogs with DOX might exert better efficacy.

企业转型视角的数字贸易发展

数字贸易在数字化时代应运而生,且其内涵随制造服务化、贸易数字化不断丰富。数字贸易发展进程体现出在线平台化、智能普适化以及跨领域联动化三大特征,为企业在贸易变局中赢得博弈延展了空间。数字技术的发展应用既是赋能企业转型也是催生数字贸易商业模式的基础,而企业数字化转型与数字贸易创新发展之间存在着双向的互促机制,即数字贸易倒逼外贸企业寻求新的管理思维和方法,企业实施数字化转型也反向推动数字贸易模式的创新发展。我国外贸企业应通过深化数字建设创造数字贸易新场景,推动融合创新开创数字贸易新业态,强化共建共享创建数字贸易新生态,加快带动数字贸易向创新链、产业链、价值链高端延伸。

A pair of G-type lectin receptor-like kinases modulates nlp20-mediated immune responses by coupling to the RLP23 receptor complex

Plant cells recognize microbial patterns with the plasma-membrane-localized pattern-recognition receptors consisting mainly of receptor kinases(RKs) and receptor-like proteins(RLPs). RKs, such as bacterial flagellin receptor FLS2, and their downstream signaling components have been studied extensively. However, newly discovered regulatory components of RLP-mediated immune signaling, such as the nlp20 receptor RLP23, await identification. Unlike RKs, RLPs lack a cytoplasmic kinase domain, instead recruiting the receptor-like kinases(RLKs) BAK1 and SOBIR1. SOBIR1 specifically works as an adapter for RLP-mediated immunity. To identify new regulators of RLP-mediated signaling, we looked for SOBIR1-binding proteins(SBPs) in Arabidopsis thaliana using protein immunoprecipitation and mass spectrometry,identifying two G-type lectin RLKs, SBP1 and SBP2, that physically interacted with SOBIR1.SBP1 and SBP2 showed high sequence similarity,were tandemly repeated on chromosome 4, and also interacted with both RLP23 and BAK1. sbp1 sbp2 double mutants obtained via CRISPR-Cas9 gene editing showed severely impaired nlp20-induced reactive oxygen species burst, mitogenactivated protein kinase(MAPK) activation, and defense gene expression, but normal flg22-induced immune responses. We showed that SBP1 regulated nlp20-induced immunity in a kinase activityindependent manner. Furthermore, the nlp20-induced the RLP23–BAK1 interaction, although not the flg22-induced FLS2–BAK1 interaction, was significantly reduced in sbp1 sbp2. This study identified SBPs as new regulatory components in RLP23 receptor complex that may specifically modulate RLP23-mediated immunity by positively regulating the interaction between the RLP23 receptor and the BAK1 co-receptor.