ABSTRACT
CsV3Sb5 exhibits superconductivity at Tc = 3.2 K after undergoing intriguing two high-temperature transitions: charge density wave order at ~98 K and electronic nematic order at Tnem ~ 35 K. Here, we investigate nematic susceptibility in single crystals of Cs(V1-xTix)3Sb5 (x = 0.00-0.06) where double-dome-shaped superconducting phase diagram is realized. The nematic susceptibility typically exhibits the CurieâWeiss behaviour above Tnem, which is monotonically decreased with x. Moreover, the CurieâWeiss temperature is systematically suppressed from ~30 K for x = 0 to ~4 K for x = 0.0075, resulting in a sign change at x = ~0.009. Furthermore, the Curie constant reaches a maximum at x = 0.01, suggesting drastically enhanced nematic susceptibility near a putative nematic quantum critical point (NQCP) at x = ~0.009. Strikingly, Tc is enhanced up to ~4.1 K with full Meissner shielding realized at x = ~0.0075-0.01, forming the first superconducting dome near the NQCP. Our findings directly point to a vital role of nematic fluctuations in enhancing the superconducting properties of Cs(V1-xTix)3Sb5.
Subject(s)
Superconductivity , Titanium , Humans , Electronics , Fever , RecordsABSTRACT
Although the induction of heme oxygenase-1 (HO-1) by hydrogen peroxide (H2O2) has been reported, the HO-1 and odontoblastic differentiation-inducing effects against H2O2 have not been clarified in human pulp cells. In this study, we investigated whether HO-1 is involved in the protective mechanisms against the cytotoxic effects of H2O2 by using a cell viability assay, and we examined the production of dentin sialophosphoprotein (DSPP) and other mineralization markers by using reverse transcriptase-polymerase chain reaction in human pulp cells. H2O2 decreased cell viability but increased HO-1 and DSPP expression in a concentration- and time-dependent manner. Antioxidants and inhibitors of HO-1, phosphatidylinositol-3'-kinase, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase blocked H2O2-induced cytotoxicity and the expression of HO-1 and DSPP mRNA in pulp cells. These data suggest that the induction of HO-1 by H2O2 in pulp cells plays a protective role against the cytotoxic effects of H2O2 and stimulates DSPP expression, resulting in premature odontoblast differentiation through pathways that involve phosphatidylinositol-3'-kinase, p38, and extracellular signal-regulated kinase.
Subject(s)
Dental Pulp/drug effects , Extracellular Matrix Proteins/biosynthesis , Heme Oxygenase-1/physiology , Hydrogen Peroxide/toxicity , Oxidants/toxicity , Blotting, Western , Cell Differentiation , Cell Survival/drug effects , Cells, Cultured , Cytoprotection , Dental Pulp/cytology , Dental Pulp/metabolism , Heme Oxygenase-1/biosynthesis , Humans , MAP Kinase Signaling System/drug effects , Odontoblasts/cytology , Oxidative Stress , Phosphoproteins/biosynthesis , RNA, Messenger/biosynthesis , Reverse Transcriptase Polymerase Chain Reaction , Sialoglycoproteins , Tooth Bleaching/adverse effectsABSTRACT
Perylenetetracarboxylic diimide (PDI) derivatives bearing two or four peripheral pyrrole pendants (PDI-nPy, n=2 or 4) are cross-linkable materials by electro/phototreatment. In this paper, we introduce a new posttreatment technique to produce an insoluble film. Unlike the common solution-phase electrochemical deposition, we first spin-coated PDI-nPy on an electrode and then electrotreated the coated surface in a monomer-free electrolyte solution. This method gives the film a smooth surface with no granules, while the common method induces a rough film with a lot of granules. The post electrochemical treatment also provides a merit of higher resolution in a patterning process on a specific metal electrode. As one of the applications, we carried out an electrochromic study on the posttreated PDI-4Py film. It turned purple (lambdamax=590 nm) and sky blue (lambdamax=797 nm) at 0 and -1.9 V vs Ag/Ag+, respectively. We believe this method will broaden the patterning concept with the desired film morphology and resolution using PDI on a specific electrode.
Subject(s)
Imides/chemistry , Perylene/analogs & derivatives , Electrochemistry , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Molecular Structure , Perylene/chemistry , Spectrum AnalysisABSTRACT
Perylenetetracarboxylic diimide derivatives bearing 2- or 4-peripheral pyrrole pendants could be efficiently crosslinked to form an insoluble film either by electropolymerization or visible light induced oxidative photopolymerization of the pyrrole units.
