Stacking-dependent electronic structure of trilayer graphene resolved by nanospot angle-resolved photoemission spectroscopy

The crystallographic stacking order in multilayer graphene plays an important role in determining its electronic structure. In trilayer graphene, rhombohedral stacking (ABC) is particularly intriguing, exhibiting a flat band with an electric-field tunable band gap. Such electronic structure is distinct from simple hexagonal stacking (AAA) or typical Bernal stacking (ABA), and is promising for nanoscale electronics, optoelectronics applications. So far clean experimental electronic spectra on the first two stackings are missing because the samples are usually too small in size (um or nm scale) to be resolved by conventional angle-resolved photoemission spectroscopy (ARPES). Here by using ARPES with nanospot beam size (NanoARPES), we provide direct experimental evidence for the coexistence of three different stackings of trilayer graphene and reveal their distinctive electronic structures directly. By fitting the experimental data, we provide important experimental band parameters for describing the electronic structure of trilayer graphene with different stackings

Effect of Phellodendron chinense Schneid Extract on Chronic Bacterial Prostatitis Induced by Chlamydia in Rats

Purpose: To explore the effects of Phellodendron chinense Schneid (PCS) extract on chlamydiainduced chronic bacterial prostatitis (CBP).Methods: Sixty 8-week-old male Sprague-Dawley rats were used in this study. Prostate index (PI) and prostate specific antigen (PSA) were determined after 4 weeks of oral administration of PCS extract (80, 160 or 320 mg/kg) or tetracycline (80 mg/kg) and compared to PI and PSA in untreated rats with CBP and healthy control rats (n = 10). Chronic inflammatory cell infiltrates, acinar changes, and interstitial fibrosis were evaluated by histopathological examination. In addition, pertinent inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), prostaglandin E2 (PEG2), transforming growth factor β1 (TGF-β1), and connective tissue growth factor (CTGF), were measured in prostate tissues using ELISA kits.Results: High doses of PCS (160 and 320 mg/kg) significantly decreased PI and PSA relative to model group (p < 0.01). PCS treatment also significantly reduced chronic inflammatory cell infiltrates and interstitial fibrosis in prostate tissue of CBP rats. In addition, TNF-α, IL-1β, COX-2, PEG2, TGF-β1, and CTGF decreased in PCS-treated rats compared to untreated control (p < 0.01).Conclusion: PCS extract has significant anti-inflammatory effects on chlamydia-induced CBP.Keywords: Phellodendron chinense Schneid, Bacterial prostatitis, Inflammatory factors, Morphometric analysis, Interstitial fibrosis, Prostate specific antigen, Prostate inde

Three-Fold Diffraction Symmetry in Epitaxial Graphene and the SiC Substrate

The crystallographic symmetries and spatial distribution of stacking domains in graphene films on SiC have been studied by low energy electron diffraction (LEED) and dark field imaging in a low energy electron microscope (LEEM). We find that the graphene diffraction spots from 2 and 3 atomic layers of graphene have 3-fold symmetry consistent with AB (Bernal) stacking of the layers. On the contrary, graphene diffraction spots from the buffer layer and monolayer graphene have apparent 6-fold symmetry, although the 3-fold nature of the satellite spots indicates a more complex periodicity in the graphene sheets.Comment: An addendum has been added for the arXiv version only, including one figure with five panels. Published paper can be found at http://link.aps.org/doi/10.1103/PhysRevB.80.24140

IRF2BP2 attenuates gestational diabetes mellitus by activating AMPK signaling

Purpose: To investigate the role of interferon regulatory factor 2 binding protein 2 (IRF2BP2) in gestational diabetes mellitus (GDM). Methods: Mice were injected intraperitoneally with streptozotocin to establish a model of GDM and then subjected to intraperitoneal glucose tolerance test (IPGTT) and intraperitoneal insulin tolerance test (IPITT) to determine glucose and insulin tolerances. Lipid metabolism was evaluated by enzyme-linked immunosorbent assay (ELISA). The histomorphology of pancreatic islets was assessed by hematoxylin and eosin staining. Results: IRF2BP2 was downregulated in pancreatic tissues of mice with GDM (p < 0.001). Mice in GDM group showed higher blood glucose levels than those in normal pregnancy group. However, overexpression of IRF2BP2 reduced glucose and insulin levels in mice with GDM. Overexpression of IRF2BP2 increased the level of high-density lipoprotein (HDL) and reduced triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) levels in mice with GDM (p < 0.001). The histopathological changes in the islets of mice with GDM were also ameliorated by overexpression of IRF2BP2. Overexpression of IRF2BP2 reduced IL-6, IL-1β, and TNF-α levels and increased protein expression of p-AMPK in mice with GDM. Conclusion: IRF2BP2 ameliorates the outcomes of GDM and suppressed inflammation in mice with GDM through activation of AMPK signaling. Thus, IRF2BP2 is a potential therapeutic strategy for the management of GDM. Keywords: IRF2BP2; inflammation; gestational diabetes mellitus; AMPK; mice; insulin toleranc