Crystal Field Effect Induced Topological Crystalline Insulators In Monolayer IV–VI Semiconductors

Two-dimensional (2D) topological crystalline insulators (TCIs) were recently predicted in thin films of the SnTe class of IV–VI semiconductors, which can host metallic edge states protected by mirror symmetry. As thickness decreases, quantum confinement effect will increase and surpass the inverted gap below a critical thickness, turning TCIs into normal insulators. Surprisingly, based on first-principles calculations, here we demonstrate that (001) monolayers of rocksalt IV–VI semiconductors XY (X = Ge, Sn, Pb and Y = S, Se, Te) are 2D TCIs with the fundamental band gap as large as 260 meV in monolayer PbTe. This unexpected nontrivial topological phase stems from the strong crystal field effect in the monolayer, which lifts the degeneracy between p_{<i>x</i>,<i>y</i>} and p_<i>z</i> orbitals and leads to band inversion between cation p_<i>z</i> and anion p_{<i>x</i>,<i>y</i>} orbitals. This crystal field effect induced topological phase offers a new strategy to find and design other atomically thin 2D topological materials

Ce/kaolin clay as an active catalyst for fatty acid methyl esters production from cottonseed oil in a new integrated apparatus

<div><p>Abstract An efficient solid acid catalyst (Ce/Kaolin clay) was prepared and investigated for transesterification of cottonseed oil to fatty acid methyl esters (FAME). The catalysts were characterized by XRD, BET, and NH3-TPD measurements. A new integrated apparatus for extraction and transesterification of cottonseed oil was developed. The effects of cerium loading, catalyst calcination temperature, methanol flow rate, reaction temperature, reaction time, and catalyst amount were also investigated. The results indicated that the Ce/Kaolin clay showed high catalytic activity under the calcination temperature of 700 oC and cerium loading of 0.05 g/g. The optimum transesterification reaction conditions were as follows: methanol flow rate 4.0 mL/min, reaction temperature 60 oC,reaction time 3 h, and catalyst amount 15 g. Under these conditions, the yield of FAME was up to 91%.The catalytic activity of Ce/Kaolin clay still remained high after 4 times of repeated use. The results indicated that the Ce/Kaolin clay catalysts had a good potential for use in the large-scale production of FAME.</p></div

Scalability of all-optical neural networks based on spatial light modulators

Optical implementation of artificial neural networks has been attracting great attention due to its potential in parallel computation at speed of light. Although all-optical deep neural networks (AODNNs) with a few neurons have been experimentally demonstrated with acceptable errors recently, the feasibility of large scale AODNNs remains unknown because error might accumulate inevitably with increasing number of neurons and connections. Here, we demonstrate a scalable AODNN with programmable linear operations and tunable nonlinear activation functions. We verify its scalability by measuring and analyzing errors propagating from a single neuron to the entire network. The feasibility of AODNNs is further confirmed by recognizing handwritten digits and fashions respectively

High Dielectric Permittivity of α‑NaFeO₂‑Type Layered Nitrides

The exploration of new high-dielectric materials is crucial for the advancement of modern electronic applications. Most previous research on high dielectrics has been limited to oxides. Here, the structures of nitrides SrHfN2 and SrZrN2 were investigated by neutron powder diffraction, which confirmed their α-NaFeO2-type layered structure without showing apparent preferences of octahedral distortion or polar structure. The SrHfN2 and SrZrN2 ceramics were found to possess high dielectric permittivities (εr) of approximately 290–650 at 106 Hz from 5 to 280 K. Impedance spectroscopy measurements indicate the ceramics could contain conducting grains and less conducting grain boundary regions with extremely small activation energies, inducing the internal barrier capacitance effect and therefore extrinsically high dielectric permittivities. Density functional theory calculations indicate that both SrHfN2 and SrZrN2 are semiconductors with ∼ 1.0 eV band gaps and possess high bulk εr values of 280 and 470, respectively. The exceptionally high εr values of these layered nitrides originate from the anisotropic and large ionic polarization within the a–b plane due to the low-frequency infrared active phonon modes concomitant with a large mode effective charge. Our study not only sheds light on the potential of high-εr materials but also provides a reference for the study of the dielectric mechanism of layered nitrides

Additional file 1: of Effect of stem cell transplantation on patients with ischemic heart failure: a systematic review and meta-analysis of randomized controlled trials

Figure S1. The PRISMA checklist for this study. (DOCX 541 kb

Additional file 4: of Effect of stem cell transplantation on patients with ischemic heart failure: a systematic review and meta-analysis of randomized controlled trials

Figure S4. Funnel plot of the studies included in the meta-analysis, which was used to test for publication bias. (DOCX 74 kb

Additional file 3: of Effect of stem cell transplantation on patients with ischemic heart failure: a systematic review and meta-analysis of randomized controlled trials

Figure S3. Risk of bias summary: review of authors’ judgements about each risk of bias item for each included study. (DOCX 289 kb

Additional file 2: of Effect of stem cell transplantation on patients with ischemic heart failure: a systematic review and meta-analysis of randomized controlled trials

Figure S2. Risk of bias graph: overview of authors’ judgements about each risk of bias item for each included study. (DOCX 85 kb

Table1_HIF-1/2α-Activated RNF146 Enhances the Proliferation and Glycolysis of Hepatocellular Carcinoma Cells via the PTEN/AKT/mTOR Pathway.DOCX

Hypoxia microenvironment, a critical feature of hepatocellular carcinoma, contributes to hepatocarcinogenesis, tumor progression and therapeutic resistance. Hypoxia-inducible factors (HIFs)-activated target genes are the main effectors in hypoxia-induced HCC progression. In this study, we identified ubiquitin E3 ligase ring finger protein 146 (RNF146) as a novel HIFs target gene. Either HIF-1α or HIF-2α knockdown significantly repressed hypoxia-induced RNF146 upregulation in Hep3B and Huh7 cells. TCGA data and our immunohistochemistry analysis consistently revealed the overexpression of RNF146 in HCC tissues. The upregulated expression of RNF146 was also detected in HCC cell lines. The high RNF146 level was correlated with poor clinical features and predicted a shorter overall survival of patients with HCC. RNF146 knockdown suppressed the proliferation, colony formation and glycolysis of HCC cells, but suppressed but RNF146 overexpression promoted these malignant behaviors. Moreover, RNF146 silencing weakened HCC growth in mice. RNF146 inversely regulated phosphatase and tensin homolog (PTEN) protein level, thereby activating the AKT/mechanistic target of rapamycin kinase (mTOR) pathway in HCC cells. MG132 reversed RNF146 overexpression-induced PTEN reduction. RNF146 knockdown decreased the ubiquitination and degradation of PTEN in HCC cells. Therefore, we clarified that PTEN knockdown notably abolished the effects of RNF146 silencing on the AKT/mTOR pathway and Hep3B cells’ proliferation, colony formation and glycolysis. To conclude, our data confirmed that RNF146 was transcriptionally regulated by HIF-1/2α and activated the AKT/mTOR pathway by promoting the ubiquitin proteolysis of PTEN, thereby contributing to HCC progression. RNF146 may be a potential new drug target for anti-HCC.</p