Novel Phases of Semi-Conducting Silicon Nitride Bilayer: A First-Principle Study

In this paper, we have predicted the stabilities of several two-dimensional phases of silicon nitride, which we name as \alpha-phase, \beta-phase, and \gamma-phase, respectively. Both \alpha- and \beta-phases has formula Si$_{2}$N$_{2}$, and are consisted of two similar layer of buckled SiN sheet. Similarly, \gamma-phase is consisted of two puckered SiN sheets. For these phases, the two layers are connected with Si-Si covalent bonds. Transformation between \alpha- and \beta-phases is difficult because of the high energy barrier. Phonon spectra of both \alpha- and \beta-phase suggest their thermodynamic stabilities, because no phonon mode with imaginary frequency is present. By Contrast, \gamma-phase is unstable because phonon modes with imaginary frequencies are found along \Gamma-Y path in the Brilliouin zone. Both \alpha- and \beta-phase are semiconductor with narrow fundamental indirect band gap of 1.7eV and 1.9eV, respectively. As expected, only s and p orbitals in the outermost shells contribute the band structures. The p$_{z}$ orbitals have greater contribution near the Fermi level. These materials can easily exfoliate to form 2D structures, and may have potential electronic applications.Comment: 9 pages, 6 figure

An efficient power plant model of electric vehicles for unit commitment of large scale wind farms

AbstractAn efficient power plant model of electric vehicles (E-EPP) considering the travelling comfort levels of EV users is developed to investigate the contribution of EVs on the unit commitment (UC) of large scale wind farms. Firstly, a generic EV battery model (GEBM) is established considering the uncertainties of battery parameters. Then, a Monte Carlo Simulation (MCS) method is implemented within the E-EPP to obtain the available response capacity of EV charging load over time. And a UC strategy using the E-EPP based on power flow tracing is developed. Finally, a modified IEEE 118-bus system integrated with wind farms is used to verify the effectiveness of the E-EPP for the UC of large scale wind farms

Synthesis of benzonaphthofuroquinones and benzoylnaphthindolizinediones by reactions of flavonoids with dichlone under basylous, oxygenous and aqueous conditions: Their cytotoxic and apoptotic activities

© 2020 The Royal Society of Chemistry. Using flavonoids and dichlone as substrates, benzonaphthofuroquinones (1, 2, 3, 5, 6, novel; 4 new) and benzoylnaphthindolizinediones (7, 8, known; 9, new) were synthesized through common base-catalyzed method and a new method of combining base-catalyzed with O2/H2O exposing. The possible reaction mechanisms may involve the process like isomerization, hydration, oxidation, decomposition and intermolecular condensation. Benzonaphthofuroquinones (2, 3, 4, 5) were found to exhibit potent cytotoxicity against carcinoma cell lines and low toxicity to normal cell lines. The compounds 4 and 5 not only expressed a significant late-stage-apoptosis against human leukemia and melanoma, but also promoted the cleavage of caspase-3 and PARP in human leukemia, which suggested that the late-stage-apoptosis and caspase-3 pathway may be responsible for the cytotoxicities of these benzonaphthofuroquinones. The replacement of the furan ring with pyrrole system in benzoylnaphthindolizinediones (7, 8, 9) resulted in the loss of anticancer activity

Effect of liver histopathology on islet cell engraftment in the model mimicking autologous islet cell transplantation

Background: The inflammatory milieu in the liver as determined by histopathology is different in individual patients undergoing autologous islet cell transplantation. We hypothesized that inflammation related to fatty-liver adversely impacts islet survival. To test this hypothesis, we used a mouse model of fatty-liver to determine the outcome of syngeneic islet transplantation after chemical pancreatectomy. Methods: Mice (C57BL/6) were fed a high-fat-diet from 6 weeks of age until attaining a weight of ≥28 grams (6–8 weeks) to produce a fatty liver (histologically > 30% fat);steatosis was confirmed with lipidomic profile of liver tissue. Islets were infused via the intra-portal route in fatty-liver and control mice after streptozotocin induction of diabetes. Outcomes were assessed by the rate of euglycemia, liver histopathology, evaluation of liver inflammation by measuring tissue cytokines IL-1β and TNF-α by RT-PCR and CD31 expression by immunohistochemistry. Results: The difference in the euglycemic fraction between the normal liver group (90%, 9/10) and the fatty-liver group (37.5%, 3/8) was statistically significant at the 18th day post- transplant and was maintained to the end of the study (day 28) (p = 0.019, X2 = 5.51). Levels of TNF–α and IL-1β were elevated in fatty-liver mice (p = 0.042, p = 0.037). Compared to controls cytokine levels were elevated after islet cell transplantation and in transplanted fatty-liver mice as compared to either fatty- or islet transplant group alone (p = NS). A difference in the histochemical pattern of CD31 could not be determined. Conclusion: Fatty-liver creates an inflammatory state which adversely affects the outcome of autologous islet cell transplantation

Bioinformatics analysis reveals TSPAN1 as a candidate biomarker of progression and prognosis in pancreatic cancer

Pancreatic cancer (PCC) is a common malignant tumor of the digestive system that is resistant to traditional treatments and has an overall 5-year survival rate of <7%. Transcriptomics research provides reliable biomarkers for diagnosis, prognosis, and clinical precision treatment, as well as the identification of molecular targets for the development of drugs to improve patient survival. We sought to identify new biomarkers for PCC by combining transcriptomics and clinical data with current knowledge regarding molecular mechanisms. Consequently, we employed weighted gene co-expression network analysis and differentially expressed gene analysis to evaluate genes co-expressed in tumor versus normal tissues using pancreatic adenocarcinoma data from The Cancer Genome Atlas and dataset GSE16515 from the Gene Expression Omnibus. Twenty-one overlapping genes were identified, with enrichment of key Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways, including epidermal growth factor receptor signaling, cadherin, cell adhesion, ubiquinone, and glycosphingolipid biosynthesis pathways, and retinol metabolism. Protein-protein interaction analysis highlighted 10 hub genes, according to Maximal Clique Centrality. Univariate and multivariate COX analyses indicated that TSPAN1 serves as an independent prognostic factor for PCC patients. Survival analysis distinguished TSPAN1 as an independent prognostic factor among hub genes in PCC. Finally, immunohistochemical staining results suggested that the TSPAN1 protein levels in the Human Protein Atlas were significantly higher in tumor tissue than in normal tissue. Therefore, TSPAN1 may be involved in PCC development and act as a critical biomarker for diagnosing and predicting PCC patient survival

Activation of Nrf2 by Sulforaphane Inhibits High Glucose-Induced Progression of Pancreatic Cancer via AMPK Dependent Signaling

Background/Aims: Sulforaphane (SFN) is known for its potent bioactive properties, such as anti-inflammatory and anti-tumor effects. However, its anti-tumor effect on pancreatic cancer is still poorly understood. In the present study, we explored the therapeutic potential of SFN for pancreatic cancer and disclosed the underlying mechanism. Methods: Panc-1 and MiaPaca-2 cell lines were used in vitro. The biological function of SFN in pancreatic cancer was measured using EdU staining, colony formation, apoptosis, migration and invasion assays. Reactive oxygen species (ROS) production was measured using 2’-7’-Dichlorofluorescein diacetate (DCF-DA) fluorometric analysis. Western blotting and immunofluorescence were used to measure the protein levels of p-AMPK and epithelial-mesenchymal transition (EMT) pathway-related proteins, and cellular translocation of nuclear factor erythroid 2-related factor 2 (Nrf2). Nude mice and transgenic pancreatic cancer mouse model were used to measure the therapeutic potential of SFN on pancreatic cancer. Results: SFN can inhibit pancreatic cancer cell growth， promote apoptosis, curb colony formation and temper the migratory and invasion ability of pancreatic cancer cells. Mechanistically, excessive ROS production induced by SFN activated AMPK signaling and promoted the translocation of Nrf2, resulting in cell viability inhibition of pancreatic cancer. Pretreatment with compound C, a small molecular inhibitor of AMPK signaling, reversed the subcellular translocation of Nrf2 and rescued cell invasion ability. With nude mice and pancreatic cancer transgenic mouse, we identified SFN could inhibit tumor progression, with smaller tumor size and slower tumor progression in SFN treatment group. Conclusion: Our study not only elucidates the mechanism of SFN-induced inhibition of pancreatic cancer in both normal and high glucose condition, but also testifies the dual-role of ROS in pancreatic cancer progression. Collectively, our research suggests that SFN may serve as a potential therapeutic choice for pancreatic cancer

Click chemistry-mediated enrichment of circulating tumor cells and tumor-derived extracellular vesicles for dual liquid biopsy in differentiated thyroid cancer

Circulating tumor cells (CTCs) and tumor-derived extracellular vesicles (tEVs) are two crucial methodologies of liquid biopsy. Given their distinct size differences and release dynamics, CTCs and tEVs potentially offer synergistic capabilities in the non-invasive detection of differentiated thyroid cancer (DTC), a typically indolent tumor. We present the Combined DTC CTC/tEV Assay, integrating dual liquid biopsy processes: i) DTC CTC enrichment by Click Chips, followed by analysis of seven DTC-specific genes, and ii) DTC tEV enrichment by Click Beads, succeeded by mRNA cargo quantification in DTC tEVs. This method utilizes click chemistry, leveraging a pair of biorthogonal and highly reactive functional motifs (tetrazine, Tz, and trans-cyclooctene, TCO), to overcome the challenges encountered in the conventional immunoaffinity-based enrichment of CTCs and tEVs. The Combined DTC CTC/tEV Assay synergistically combines the diagnostic precision of CTCs with the sensitivity of tEVs, demonstrating superior diagnostic accuracy in DTC detection and boasting an AUROC of 0.99. This outperforms the individual diagnostic performance of using either DTC CTC or DTC tEV alone. This integration enables full utilization of a patient's blood sample, and marks a significant evolution in the development of nanomaterial-based liquid biopsy technologies to address challenging unmet clinical needs in cancer care