RUNX3 protects against acute lung injury by inhibiting the JAK2/STAT3 pathway in rats with severe acute pancreatitis.

OBJECTIVE: Acute lung injury (ALI) is the most common complication of severe acute pancreatitis (SAP) in the early stage, which causes systemic inflammatory response and organ damage. Human runt-associated transcription factor 3 gene (RUNX3) has been reported to participate in various inflammatory diseases. However, the exact role of RUNX3 in SAP and its-related ALI remains unclear. MATERIALS AND METHODS: To establish the model of SAP, rats were retrogradely injected with 5% sodium taurocholate (1 mg/kg body weight) into the biliary-pancreatic duct. Cytokine level in serum was measured by ELISA, and the polymorphonuclear neutrophil (PMN) was isolated from rat's blood 12 h-post SAP induction. RESULTS: We found RUNX3 expression was significantly decreased with the progression of SAP. Both pancreas damages and cytokine production abilities were reduced in RUXN3-overexpressed SAP rats compared with control rats. Moreover, SAP-associated ALI was also improved upon RUNX3 overexpression in SAP rats. RUNX3 upregulation enhanced PMN apoptosis and inhibited Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) phosphorylation. CONCLUSIONS: Our study indicates that RUNX3 protects against SAP and SAP-associated ALI through controlling PMN apoptosis and regulating JAK2/STAT3 signaling pathway. RUNX3 could be regarded as a potent therapeutic target in SAP for future studies.

Identifying the germ cells during embryogenesis and gametogenesis by germ-line gene vasa in an anadromous fish, American shad Alosa sapidissima.

American shad Alosa sapidissima, an anadromous clupeid, exhibits variation in reproductive strategies, including semelparity and iteroparity. It provides an excellent model for studying the behaviour of germ cells in anadromous fish during their migration from sea to river. The vasa gene was characterized in A. sapidissima as a germ-cell marker to elaborate the process of germ-cell development and differentiation in anadromous species. A complementary (c)DNA fragment of 819 bp, partial open reading frame (ORF), was cloned by degenerate PCR and named as ASvas. In adult A. sapidissima, vasa transcript was exclusively detected in gonads by reverse-transcription (RT)-PCR. Through chromogenic in situ hybridization, the vasa messenger (m)RNA was specifically detected in primordial germ cells (PGC) in embryos and germ cells at early stages in ovary and testis. Besides, the cellular distribution profile of Vasa protein also proved that vasa gene could be used as a germ-line marker to trace the PGCs migration during embryogenesis and the germ-cell differentiation during gametogenesis in A. sapidissima. During embryogenesis, the migrating PGCs were clearly detected at tail-bud stage and the PGCs reached the genital ridge at the stage of pre-hatching stage in A. sapidissima embryos. During gametogenesis, the Vasa protein was dynamically expressed in differentiating germ cells at different stages in adult gonads. As far as we know, this is the first report to demonstrate the PGCs migration and germ-cell differentiation through vasa gene expression in the anadromous species. The findings will pave a way for investigating germ-cell development and maturation in the A. sapidissima and other anadromous fish.

Molecular dynamics study of the structures and dynamics of the iodine molecules confined in AlPO(4)-11 crystals.

Structural and dynamical properties of iodine molecules incorporated in one-dimensional elliptic channels of AlPO(4)-11 (AEL) crystals were studied by means of molecular dynamics (MD) simulations. It was found that the iodine molecules in the AEL channels are restricted in the (101) planes with only two favorite orientations: lying along the channels and standing along the major axes of the ellipses, which are well consistent with the experimental observations. In addition, the iodine structures are largely dependent on the loading level: with the increase of loading, the iodine specimens change their structures accordingly from isolated molecules as in the gas phase to single molecular chains and molecular ribbon sheets. The molecular ribbon sheets are composed of equally distributed and parallel molecules as in the iodine crystals. The simulation results show that the standing iodine molecules in the AEL channels are well restricted due to both the appropriate size of ellipses and their alternation throughout the channels. They can diffuse along the channels only after overcoming the rotational barriers to become lying molecules, which indicate that the iodine molecules in the ribbon sheets can keep the configurations without rotational and translational motion. The confined iodine molecules with such structures and properties may be used to improve the accuracy of the frequency standards.

Resonant Raman scattering of the smallest single-walled carbon nanotubes.

We report optical properties of the smallest single-walled carbon nanotubes (SWNTs) with a diameter of only 3 A. These ultrasmall SWNTs are fabricated in the elliptical nanochannels of an AlPO-11 (AEL) single crystal. Polarized and resonant Raman scattering unambiguously revealed that these 0.3 nm SWNTs are of (2,2) armchair symmetry. Interestingly, the (2,2) armchair tube has two metastable ground states corresponding to two slightly different lattice constants in the axial direction: one state is metallic and the other is semiconducting.

Synthesis and characterization of iodine molecular wires in channels of zeolite AEL single crystals.

Well-aligned iodine molecular wires were synthesized by means of loading iodine molecules in the elliptical nanometer-scale channels of AlPO(4)-11 (AEL) single crystals. Polarized Raman spectra reveal that the iodine molecular wires are oriented along the crystal channel direction by lining iodine molecules on the yz plane, where y and z represent the channel direction and the major-axial direction of the elliptical rings, respectively. Natural iodine wires are unstable, but they are very stable in the AEL channels. The template technique offers us an ideal platform to study the novel properties of these molecular wires.

Assembly of disperse red 1 molecules in the channels of AlPO4-5 single crystals for second-harmonic generation.

Disperse red 1 (DR1) molecules have been successfully incorporated into the one-dimensional channels of AlPO4-5 single crystals by means of vapor-phase diffusion. Polarizing microscope and SHG results indicate that the DR1 molecules are well aligned in a preferred direction along the crystal channels. The p-polarization (parallel to the c-axis of AlPO4-5 crystal) SH intensity (Ip-ex), and s-polarization (perpendicular to the c-axis of AlPO4-5 crystal) SH intensity (Is-ex) of DR1-loaded AlPO4-5 single crystals can be well fitted as a function of input polarization angle (alpha): Ip-ex = 0.69 cos4 alpha + 0.37 sin4 alpha - 0.17, Is-ex = 0.69 cos2 alpha sin2 alpha + 0.06, respectively. This polarization angle dependence can be well explained by three different SHG processes of Ip (0 degrees), Ip (90 degrees), and Is (45 degrees), originated from different combinations of two polarized photons.

Multiwalled carbon nanotube supported PtRu for the anode of direct methanol fuel cells.

The activity of the methanol oxidation reaction of a multiwalled carbon nanotube (MWCNT)-supported PtRu catalyst was investigated and compared with the Vulcan XC-72 carbon-supported catalyst. The PtRu nanoparticles with 1:1 and 7:3 atomic ratios (with similar PtRu loadings and morphological structures) were deposited both on the MWCNTs and on the carbon. Cyclicvoltammetry results demonstrated that the MWCNT-supported PtRu catalyst exhibited a higher mass activity (mA mg(-1) of PtRu) for the methanol oxidation reaction than the carbon-supported PtRu under the condition that both catalysts possess more or less the same PtRu loadings, particle sizes, dispersions, and electrochemical surface area. The direct methanol fuel cell performance test data showed that MWCNT-supported PtRu catalysts yielded about 35-39% higher power densities than the carbon-supported PtRu.

Polarized absorption spectra of single-walled 4 A carbon nanotubes aligned in channels of an AlPO(4)-5 single crystal.

We report the polarized optical absorption spectra of single-walled 4 A carbon nanotubes arrayed in the channels of an AlPO (4)-5 single crystal. When the light electric field (E) is polarized parallel to the tube direction (c), the spectra display a sharp peak at 1.37 eV, with two broadbands at 2.1 and 3.1 eV. In the E perpendicular c configuration, the tube is nearly transparent in the measured energy region 0.5-4.1 eV. The optical dipole selection rules are discussed, and the absorption bands are assigned to the dipole transitions between the Van Hove singularities. The measured absorption spectra agreed well with the ab initio calculations of band structure based on the local density function approximation.

Superconductivity in 4 angstrom single-walled carbon nanotubes.

Investigation of the magnetic and transport properties of single-walled small-diameter carbon nanotubes embedded in a zeolite matrix revealed that at temperatures below 20 kelvin, 4 angstrom tubes exhibit superconducting behavior manifest as an anisotropic Meissner effect, with a superconducting gap and fluctuation supercurrent. The measured superconducting characteristics display smooth temperature variations owing to one-dimensional fluctuations, with a mean-field superconducting transition temperature of 15 kelvin. Statistical mechanic calculations based on the Ginzburg-Landau free-energy functional yield predictions that are in excellent agreement with the experiments.