Piezoelectric ferromagnetism in Janus monolayer YBrI: a first-principles prediction.

Coexistence of intrinsic ferromagnetism and piezoelectricity, namely piezoelectric ferromagnetism (PFM), is crucial to advance multifunctional spintronic technologies. In this work, we demonstrate that Janus monolayer YBrI is a PFM, which is dynamically, mechanically and thermally stable. The electronic correlation effects on the physical properties of YBrI are investigated by using generalized gradient approximation plus U (GGA+U) approach. For out-of-plane magnetic anisotropy, YBrI is a ferrovalley (FV) material, and its valley splitting is larger than 82 meV within the considered U range. The anomalous valley Hall effect (AVHE) can be achieved under an in-plane electric field. However, for in-plane magnetic anisotropy, YBrI is a common ferromagnetic (FM) semiconductor. When considering intrinsic magnetic anisotropy, the easy axis of YBrI is always in-plane, and its magnetic anisotropy energy (MAE) varies from 0.309 meV to 0.237 meV (U = 0.0 eV to 3.0 eV). However, the magnetization can be adjusted from the in-plane to out-of-plane direction by an external magnetic field, and then lead to the occurrence of valley polarization. Moreover, the missing centrosymmetry along with broken mirror symmetry results in both in-plane and out-of-plane piezoelectricity in the YBrI monolayer. At a typical U = 2.0 eV, the piezoelectric strain coefficient d11 is predicted to be -5.61 pm V-1, which is higher than or comparable with the ones of other known two-dimensional (2D) materials. The electronic and piezoelectric properties of YBrI can be effectively tuned by applying biaxial strain. For example, tensile strain can enhance valley splitting and d11 (absolute value). The predicted magnetic transition temperature of YBrI is higher than those of experimentally synthesized 2D FM materials CrI3 and Cr2Ge2Te6. Our findings of these distinctive properties could pave the way for designing multifunctional spintronic devices, and bring forward a new perspective for constructing 2D materials.

Predicted intrinsic piezoelectric ferromagnetism in Janus monolayer MnSbBiTe4: a first principles study.

Two-dimensional (2D) piezoelectric ferromagnetism (PFM) is essential for the development of the next-generation multifunctional spintronic technologies. Recently, the layered van der Waals (vdW) compound MnBi2Te4 as a platform to realize the quantum anomalous Hall effect (QAHE) has attracted great interest. In this work, the Janus monolayer MnSbBiTe4 with dynamic, mechanical and thermal stabilities is constructed from a synthesized non-piezoelectric MnBi2Te4 monolayer by replacing the top Bi atomic layer with Sb atoms. The calculated results show that monolayer MnSbBiTe4 is an intrinsic ferromagnetic (FM) semiconductor with a gap value of 0.25 eV, whose easy magnetization axis is out-of-plane direction with magnetic anisotropy energy (MAE) of 158 µeV per Mn. The predicted Curie temperature TC is about 20.3 K, which is close to that of monolayer MnBi2Te4. The calculated results show that the in-plane d11 is about 5.56 pm V-1, which is higher than or comparable to those of other 2D known materials. Moreover, it is found that strain engineering can effectively tune the piezoelectric properties of Janus monolayer MnSbBiTe4. The calculated results show that tensile strain can improve the d11, which is improved to be 21.16 pm V-1 at only 1.04 strain. It is proved that the ferromagnetic order, semiconducting properties, out-of-plane easy axis and a large d11 are robust against electronic correlations. Our work provides a possible way to achieve PFM with a large d11 in well-explored vdW compound MnBi2Te4, which makes it possible to use the piezoelectric effect to tune the quantum transport process.

Evodiamine has therapeutic efficacy in ulcerative colitis by increasing Lactobacillus acidophilus levels and acetate production.

Emerging evidence implicates gut microbiota have an important role in ulcerative colitis (UC). Previous study indicated that Evodiamine (EVO) can alleviate colitis through downregulating inflammatory pathways. However, specific relationship between EVO-treated colitis relief and regulation of gut microbiota is still unclear. Here, our goal was to determine the potential role of gut microbiota in the relief of UC by EVO. By using pathology-related indicators, 16S rRNA sequencing and metabolomics profiling, we assessed the pharmacological effect of EVO on dextran sulfate sodium (DSS)-induced colitis rats as well as on the change of gut microbiota and metabolism. Fecal derived from EVO-treated rats was transplanted into colitis rats to verify the effect of EVO on gut microbiota, and 'driver bacteria' was found and validated by 16S rRNA sequencing, metagenome and qRT-PCR. The effect of Lactobacillus acidophilus (L. acidophilus) was investigated by vivo experiment, microbiota analysis, Short-chain fatty acids (SCFAs) quantification and colon transcriptomics. EVO reduced the susceptibility to DSS-induced destruction of epithelial integrity and severe inflammatory response, and regulated the gut microbiota and metabolites. Fecal Microbiota Transplantation (FMT) alleviated DSS-induced colitis, increased the abundance of L. acidophilus and the level of acetate. Furthermore, gavaged with L. acidophilus reduced pro-inflammatory cytokines, promoted the increase of goblet cells and the secretion of antimicrobial peptides, regulated the ratio of Firmicutes/Bacteroidetes and increased the level of acetate. Our results indicated that EVO mitigation of DSS-induced colitis is associated with increased in L. acidophilus and protective acetate production, which may be a promising strategy for treating UC.

Discovery of N-Aroyl Diketone/Triketone Derivatives as Novel 4-Hydroxyphenylpyruvate Dioxygenase Inhibiting-Based Herbicides.

4-Hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) is an important target site for discovering new bleaching herbicides. To explore novel HPPD inhibitors with excellent herbicidal activity, a series of novel N-aroyl diketone/triketone derivatives were rationally designed by splicing active groups and bioisosterism. Bioassays revealed that most of these derivatives displayed preferable herbicidal activity against Echinochloa crus-galli (EC) at 0.045 mmol/m2 and Abutilon juncea (AJ) at 0.090 mmol/m2. In particular, compound I-f was more potent compared to the commercialized compound mesotrione. Molecular docking indicated that the corresponding active molecules of target compounds and mesotrione shared similar interplay with surrounding residues, which led to a perfect interaction with the active site of Arabidopsis thaliana HPPD.

[Protective effects and underlying mechanisms of Panax notoginseng saponins against SH-SY5Y cell apoptosis induced by 6-hydroxydopamine].

The aim of this study is to investigate the protective effects of Panax notoginseng saponins (PNS) against 6-hydroxydopamine(6-OHDA)-induced apoptosis in SH-SY5Y cells and the possible underlying mechanisms. Cell viability was examined by MTT assay. The levels of lactate dehydrogenase(LDH), reactive oxygen species (ROS), malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase(GSH-Px) were measured using the respective assay kits. Apoptosis was measured by TUNEL kit, JC-1 and ROS was measured by staining with fluorescent dyes. The activation of caspase-3 was measured with the caspase-3 assay kit. The expression of nuclear protein Nrf2 and HO-1 were determined by Western blot. PNS had significant protective effects against 6-OHDA-induced apoptosis in SH-SY5Y cells in a time- and dose-dependent manner. PNS could attenuate 6-OHDA-induced suppression of SOD, GAT, GSH-Px (P < 0.01). PNS reduced the level of LDH, decreased the levels of ROS, MDA and increased cell viability and the mitochondrial membrane potential (P < 0.01). PNS also inhibited DNA fragmentation, mitochondrial response and the activation of caspase-3 (P < 0.01). Moreover, PNS pretreatment increased the expression of the nuclear Nrf2 and up-regulate HO-1. The protective effects of PNS could be inhibited by HO-1 inhibitor SnPP. In conclusion, PNS has significant protective effects against 6-OHDA- induced apoptosis in SH-SY5Y cells. The possible mechanisms of PNS are due to PNS-mediated activation of Nrf2, up-regulation of HO-1 and inhibition of oxidative stress.

[The anesthesiologic value of transcutaneous acupoint electrical stimulation combined with general intravenous anesthesia in endoscopic thyroidectomy patients: a clinical study].

OBJECTIVE: To explore the clinical anesthesia value of transcutaneous acupoint electrical stimulation (TAES) combined with general intravenous anesthesia in endoscopic bilateral thyroidectomy patients. METHODS: Totally 60 patients who underwent endoscopic bilateral thyroidectomy were equally randomly assigned to 2 groups, the treatment group and the control group, 30 in each group. Patients in the treatment group received TAES combined general intravenous anesthesia, while those in the control group received total intravenous anesthesia. Anesthesia was maintained by target controlled infusion of propofolum combined constant speed infusion of remifentanil in the two groups. TAES was maintained from 30 min before anesthesia induction to the end of endoscopic thyroidectomy at bilateral Hegu (L14) and Neiguan (PC6). The mean artery pressure (MAP) and heart rate (HR) were recorded at different time points of anesthesia, i.e., immediately after entry into the operating room (TO), immediately after intubation (T1), 5 min after intubation (T2), 5 min before incision (T3), 5 min after incision (T4), 30 min after inflation (T5), at the end of surgery (T6), 5 min before extubation (T7), immediately after extubation 0 (T8), and 5 min after extubation (T9). The concentration of IL-6 and TNF-alpha were measured at TO, T3, T5, and T6. The target concentration of propofol was also recorded at T3, T4, and T5. RESULTS: There was no statistical difference in the operation time between the two groups (P >0.05). Compared with TO in the same group, HR at T3-T4 decreased and increased at T8-T9, and MAP increased at T7-T9 in the treatment group; HR decreased at T3 and increased at T7-T9, MAP increased at T1, T5, T7-T9, and MAP decreased at T2-T3 in the control group. IL-6 increased at T5-T6, while TNF-alpha decreased at T6 in the two groups (P <0.01,P <0.05). Compared with the control group at the same time point, HR decreased at T6-T9, MAP decreased at T1, T4, T5, T7-T9, MAP increased at T3, and IL-6 decreased at T5-T6 in the treatment group (P <0. 05). The concentration and the total amount of propofol were significantly lower in the treatment group than in the control group (P <0.01,P <0.05). CONCLUSIONS: TAES could maintain the hemodynamics more stably and inhibit the stress response in endoscopic thyroidectomy. It also reduce the dosage of anesthetics and improve the safety of anesthesia.