Prediction of Nontrivial Band Topology and Superconductivity in Mg2_2Pb

The interplay of BCS superconductivity and nontrivial band topology is expected to give rise to opportunities for creating topological superconductors, achieved through pairing spin-filtered boundary modes via superconducting proximity effects. The thus-engineered topological superconductivity can, for example, facilitate the search for Majorana fermion quasiparticles in condensed matter systems. Here we report a first-principles study of Mg$_2$Pb and predict that it should be a superconducting topological material. The band topology of Mg$_2$Pb is identical to that of the archetypal quantum spin Hall insulator HgTe, while isostructural and isoelectronic Mg$_2$Sn is topologically trivial; a trivial to topological transition is predicted for Mg$_2$Sn$_{1-x}$Pb$_x$ for x~0.77. We propose that Mg$_2$Pb-Mg$_2$Sn quantum wells should generate robust spin-filtered edge currents in analogy to HgTe/CdTe quantum wells. In addition, our calculations predict that Mg$_2$Pb should become superconducting upon electron doping. Therefore, Mg$_2$Pb is expected to provide a practical material platform for studying emergent phenomena arising from the interplay of superconductivity and band topology.Comment: 5 figure

The nondepolarizing, normokalemic cardioplegia formulation adenosine-lidocaine (adenocaine) exerts anti-neutrophil effects by synergistic actions of its components

ObjectiveA new strategy of normothermic cardioplegia based on the combination of adenosine and lidocaine (adenocaine; Hibernation Therapeutics Global Ltd, Kilquade, Ireland) achieves nondepolarized arrest at normokalemia. Both adenosine and lidocaine independently inhibit neutrophil (polymorphonuclear neutrophil; PMN) activity. However, whether adenocaine exerts greater anti-inflammatory effects is not known. We tested the hypothesis that adenocaine synergistically attenuates PMN functions.MethodsSuperoxide anion (O2−) generation: Isolated porcine PMNs were primed with cytochalasin B (5 μg/mL) and activated by N-formylmethionyl-leucyl-phenylalanine (100 nM). O2− release was quantified using lucigenin-enhanced chemiluminescence. Data were expressed as percent of stimulated control.ResultsBoth adenosine and lidocaine alone inhibited O2− production in a dose-dependent manner (adenosine reduced to 67% ± 8.4% and 21% ± 2.2% of maximal stimulation at 0.1 and 10 μmol/L, respectively, lidocaine reduced to 57.9% ± 18.6% and 28% ± 5% at 10 and 100 μmol/L, respectively). Adenocaine further reduced O2− generation in a synergistic manner. In addition, adenosine alone (0.1–10 μmol/L) inhibited O2− generation in primed but not activated PMNs, whereas lidocaine alone (1–100 μmol/L) inhibited O2− release in both primed and activated PMNs. Adenocaine further reduced O2− generation because of inhibition of both priming and activation stages. Both adenosine and lidocaine alone and adenocaine comparably inhibited platelet activating factor–induced CD11 b/c surface expression on PMNs (flow cytometry), but adenocaine further suppressed both CD18 expression (to 47.4% ± 9.7%) and PMN adherence (to 47.2% ± 4.3%) compared with adenosine and lidocaine alone. Transmigration of calcein-acetyoxymethyl–labeled PMNs through transwells seeded with cultured coronary artery endothelial cells was reduced comparably by adenosine (to 80.1% ± 6.7%) and adenocaine (67.3% ± 9.6%).ConclusionsAdenocaine suppresses multiple PMN functions including O2− generation, adhesion molecule expression, PMN adherence, and transmigration. In addition to inducing nondepolarized arrest, adenocaine cardioplegia may exert cardioprotection by inhibiting PMN-mediated inflammatory responses

Novel insights into circular RNAs in clinical application of carcinomas

Circular RNAs (circRNAs), formed by nonsequential back-splicing of pre-messenger RNA (pre-mRNA) transcripts, have been widely concerned in recent years. With advances in high-throughput RNA sequencing (RNA-seq) technology, previous work has revealed that a large number of circRNAs, which are endogenous, abundant and stable in mammalian cells, may be involved in atherosclerotic vascular disease risk, neurological disorders, prion diseases and carcinomas. Remarkably, interaction between circRNAs and microRNA has already been observed to perform a significant role in a variety of cancers, including gastric cancer and colorectal cancer. Recent work has suggested that circRNAs may play critical roles in the initiation and development of cancers and could become potential new biomarkers for cancers. Herein, we review the current understanding of the roles of circRNAs in cancers and the potential implications of circRNAs in cancer-targeted therapy

Metabonomic Study on the Antidepressant-Like Effects of Banxia Houpu Decoction and Its Action Mechanism

The aim of this study was to establish an experimental model for metabonomic profiles of the rat’s brain and then to investigate the antidepressant effect of Banxia Houpu decoction (BHD) and its possible mechanisms. Behavioral research and metabonomics method based on UPLC-MS were used to assess the efficacy of different fractions of BHD on chronic unpredictable mild stress (CUMS) model of depression. There was a significant difference between the BHD group and the model group. Eight endogenous metabolites, which are contributing to the separation of the model group and control group, were detected, while BHD group regulated the perturbed metabolites showing that there is a tendency of recovery compared to control group. Therefore, we think that those potential metabolite biomarkers have some relationship with BHD’s antidepression effect. This work appraised the antidepressant effect of Banxia Houpu decoction as well as revealing a metabonomics method, a valuable parameter in the TCM research

Facilitating granule cell survival and maturation in dentate gyrus with baicalin for antidepressant therapeutics

Baicalin isolated from Scutellaria baicalensis possesses antidepressant abilities through its relation to hippocampal neurogenesis. Current research has found that baicalin can promote the proliferation of hippocampal granule cells, however, the detailed mechanism of baicalin on the survival and maturation of hippocampal granule cells has yet to be sufficiently explored. The purpose of this study was to evaluate whether baicalin could facilitate the survival and maturation of hippocampal granule cells, and to explore its potential mechanism. The chronic corticosterone (CORT)-induced mouse model of depression was used to assess antidepressant-like effects of baicalin and to illuminate possible molecular mechanisms by which baicalin affects hippocampal neurogenesis. The survival and maturation of granule cells were measured by immunohistochemistry, immunofluorescence and Golgi staining. The expression of Phosphatidylinositol 3-kinase (PI3K)/Protein kinase B (AKT)/glycogen synthase kinase-3β (GSK3β)/β-catenin pathway related proteins were measured by western blot analysis. PI3K inhibitor LY292002 and AKT inhibitor Perifosine were administered to HT-22 cells to explore the relationship between the PI3K/AKT/GSK3β/β-catenin pathway and baicalin. The results of the study illustrated that baicalin significantly decreased chronic CORT-induced depressive-like behaviors and reduced serum corticosterone levels. In addition, baicalin (administered at 60 mg/kg) reversed chronic CORT-induced lesions on hippocampal granule cells. Moreover, baicalin significantly increased the phosphorylation rate of PI3K, AKT, GSK3β, and total β-catenin. The study found that administration of LY292002/Perifosine counteracted the effects of baicalin in HT-22 cells. These results demonstrate that baicalin can alleviate chronic CORT-induced depressive-like behaviors through promoting survival and maturation of adult-born hippocampal granule cells and exhibiting protective effect on hippocampal neuron morphology. We propose the underlying mechanisms involve the activation of the PI3K/AKT/GSK3β/β-catenin pathway