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A simple 4-aniline boron-dipyrromethene (BODIPY) dye (1) was developed as a highly sensitive acidic pH fluorescent probe excitable with visible light based on a photoinduced electron transfer (PeT) mechanism. The pH titration indicates that the fluorescence intensity increases more than 500-fold within the pH range of 4.12-1.42 with a pKa value of 3.24 in methanol-water (1 : 1, v/v) solution, which is valuable for studying strongly acidic conditions. Density functional theory (DFT) calculations reproduce the fluorescence off-on behavior. 1 has also been used as a fluorescent chemosensor for the visual detection of dissolved carbon dioxide (CO2) gas. The underlying mechanism of the sensing process is rationalized. This probe can be recovered by bubbling nitrogen (N2) gas into CO2-treated solutions for over 10 cycles. In addition, two logic gates (OR and INH) have been achieved at the molecular level by changing the initial states of system 1 and chemical inputs.

A mixed-ligand Ag(I) coordination polymer {[Ag2(bpe)2(H2O)2](chd)·5H2O}n (1) (bpe = 4,4′-bipyridylethylene, H2chd = 1,4-cyclohexanedicarboxylic acid), has been synthesized and structurally characterized. Complex 1 exhibits a three-dimensional (3-D) supramolecular sandwich architecture that is composed of cationic chains of Ag(I) ions and bpe ligands, alternating with anionic sheets in which uncoordinated chd2 − anions and water molecules form a 2-D hydrogen-bonded network. An odd-numbered (H2O)7 cluster is trapped inside the water-chd aggregation. The discrete water heptamer consists of a puckered pentameric core and two pendent water molecules and structurally shows similarity to the simple hydrocarbon (1,1)-dimethylcyclopentane.

The ultrasonic reaction of Ag2O, 1,3-bis(4-pyridyl)propane (bpp) and Na2B4O5(OH)4·8H2O (borax) under ammoniacal medium gave rise to an unexpected 3D Ag(I) supramolecular sandwich lamellar framework, {[Ag2(bpp)2(H2O)2]·[(H3BO3)3(CO3)·2H2O]}n (1), which consists of 2D silver-bpp cationic host and water–borate–carbonate anionic guest layers. The present 2D anionic layer is formed by fused H2O–H3BO3–CO32 − anionic rosette ribbons, in which H3BO3 is obtained via in situ hydrolysis of borax and CO32 − derived from absorption of CO2 in air. Interestingly, an unprecedented [CO32 −·3(H3BO3)] hydrogen-bonding aggregate having the shape of one concave three-leaved propeller is found in the anionic rosette ribbon.

The ultrasonic reaction of Ag2O, bipy and H2aze gave rise to a novel Ag(I) mixed-ligand coordination polymer, namely [Ag(aze)(bipy)]·(H2O)3 (1) (bipy = 4,4′-bipyridine, H2aze = azelaic acid). In 1, Ag(I) ions are linked by bipy and aze ligands to form a single two-dimensional (2D) undulated net with a (6,3) topology, incorporating Ag6(bipy)4(aze)2 windows of 22.58 × 11.06 A based on Ag⋯Ag distances. A pair of identical 2D single nets are interconnected via π⋯π stacking and unsupported Ag⋯Ag interactions to generate a 2D double-layered net. A discrete water hexamer composed of a new planar tetrameric water ring and two pendent water molecules is perpendicularly located in each hydrophilic cavity of the 2D bilayer and acts as a ‘glue’ to assemble adjacent 2D double-layered nets into a three-dimensional (3D) structure.

The electronic transport properties are the basis for investigations on silicon carbide nanotube (SiCNT), which are suitable to develop novel nanometer electronic devices. The electronic transport properties of Single-Walled (8, 0) SiCNTs with antisite defects are investigated with the method combined Non-Equilibrium Green’s function with density functional theory. Results show that the similarity on electronic transport properties of the nanotube with different defects is high. Under a bias value greater than 1.0 V, a nearly exponential relationship between the bias and the current is achieved, which originates from more orbital participating in its transport properties caused by the increase of the bias.

To explore a novel sensor to detect the presence of nitrogen dioxide (NO2), we investigate reactivity of boron-doped (B-doped) single-walled (8,0) silicon carbide nanotube (SiCNT) with NO2. Based on density functional theory, the structure and electronic properties of the B-doped SiCNT with and without the adsorption of NO2 molecule have been calculated. Results show that a stable adsorption between the nanotube and the gas molecule is formed and the conductivity of the SiCNT is improved obviously. B-doped SiCNT is expected to be a potential candidate for detecting the presence of NO2.

A supercell of a nanotube heterojunction formed by an (8, 0) carbon nanotube (CNT) and an (8, 0) silicon carbide nanotube (SiCNT) is established, in which 96 C atoms and 32 Si atoms are included. The geometry optimization and the electronic property of the heterojunction are implemented through the first-principles calculation based on the density functional theory (DFT). The results indicate that the structural rearrangement takes place mainly on the interface and the energy gap of the heterojunction is 0.31 eV, which is narrower than those of the isolated CNT and the isolated SiCNT. By using the average bond energy method, the valence band offset and the conduction band offset are obtained as 0.71 and −0.03 eV, respectively.

Background Endothelial-to-mesenchymal transition (EndoMT) is a crucial event during kidney interstitial fibrosis and it is believed to be inhibited by netrin-1. Our aim was to determine the influence of netrin-1 on renal EndoMT in chronic kidney disease by studying its effect in 5/6 nephrectomized (Nx) rats. Methods Male Sprague–Dawley rats were divided into three groups (10 rats/group): sham-operated rats treated with control adenovirus; 5/6 Nx rats treated with control adenovirus; and 5/6 Nx rats treated with recombinant adenovirus expressing the netrin-1 gene (Ad-netrin-1). Rats were sacrificed 13 weeks after surgery. Blood urea nitrogen (BUN) and serum creatinine (Scr) levels were measured regularly after surgery. After the rats were sacrificed, pathological changes in renal tissues were analyzed histologically. Immunofluorescence was performed to evaluate the co-expression of CD31 and α-SMA. CD31, α-SMA and Snail mRNA were detected by RT-PCR. Protein expression was detected by western blot. Results Renal function and histopathological damage were significantly improved in Ad-netrin-1-treated 5/6 Nx rats. In the sham and control-treated 5/6 Nx rats, the percentage of CD31+/α-SMA+ cells increased, which indicated EndoMT. However, the percentage of CD31+/α-SMA+ cells were reduced in the netrin-1-treated 5/6 Nx rats, which indicates netrin-1-induced blocking of EndoMT. Conclusion From the results, it seems that netrin-1 attenuates the progression of renal dysfunction by inhibiting EndoMT in 5/6 Nx rats. Netrin-1 can therefore be considered as a potential therapeutic agent for the treatment of renal fibrosis.

The aim of this study was to investigate the protective effects of Mimic of Manganese superoxide dismutase (MnSODm) against carbon tetrachloride (CCl(4))-induced hepatic injury in mice. Bifendate or MnSODm was intragastrically administered per day for 7 days. On the 8th day, all mice except the normal group were given 0.5% CCl(4)/peanut oil to induce hepatic injury model by intraperitoneal injection. Mice were sacrificed 24 h after CCl(4) treatment. Compared with the CCl(4) group, MnSODm significantly decreased the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the serum and liver. Moreover, the contents of hepatic and serum malondialdehyde (MDA) and nitric oxide (NO) with inducible nitric oxide synthase (iNOS) activities were reduced. Histological findings also confirmed the antihepatotoxic characterization. In addition, MnSODm inhibited the pro-inflammatory mediators, such as prostaglandin E(2) (PGE(2)), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Further investigation showed that the inhibitory effect of MnSODm on the pro-inflammatory cytokines was associated with the down-regulation of nuclear factor-kappa B (NF-κB). In brief, our results show that the protective effect of MnSODm against CCl(4)-induced hepatic injury may rely on its ability to reduce oxidative stress and suppress inflammatory responses.

4-Methoxycarbonylphenyl-substituted BODIPY (boron-dipyrromethene) dye gives, in the solid state, three polymorphs. In spite of the absence of any strong intermolecular interactions in all crystalline forms, the three polymorphs show different photoluminescence properties. This behavior highlights the importance of molecular arrangements of the BODIPY moieties in the crystalline state in perturbing their photophysical properties.

Electronic structure and optical properties of a (5, 5) single-walled silicon carbide nanotube are studied with first principles calculation based on density functional theory. Depression and salient are formed near CSi defect and SiC defect in the surface of the nanotube. Defect energy levels are formed near the bottom of conduction band, which results in an n-type conductivity for nanotubes with antisite defects. In dielectric functions parallel and perpendicular to the axis of the nanotube, novel resonance peak is formed from transitions between top of the conduction band and the defect energy level.

Two novel hydrated adipate dianions including (adip)aaa·(H2O)16 and (adip)gag·(H2O)20 (adip = dianion of adipic acid, aaa = anti–anti–anti and gag = gauche–anti–gauche) were observed in two silver-based cationic hosts. They not only reveal the precise arrangement of water clusters around the carboxylate groups and aliphatic chains of adipate dianions, but show the conformational change of adipate dianions in water clusters, for the first time.

The electronic transport properties of the armchair silicon carbide nanotube (SiCNT) are investigated by using the combined nonequilibrium Green's function method with density functional theory. In the equilibrium transmission spectrum of the nanotube, a transmission valley of about 2.12 eV is discovered around Fermi energy, which means that the nanotube is a wide band gap semiconductor and consistent with results of first principle calculations. More important, negative differential resistance is found in its current voltage characteristic. This phenomenon originates from the variation of density of states caused by applied bias voltage. These investigations are meaningful to modeling and simulation in silicon carbide nanotube electronic devices.

The electronic structure of the heterojunction is the foundation of the study on its working mechanism. Models of the heterojunctions formed by an (8, 0) boron nitride nanotube and an (8, 0) carbon nanotube with C–B or C–N interface have been established. The structures of the above heterojunctions were optimized with first-principle calculations based on density functional theory. The rearrangements of the heterojunctions concentrate mainly on their interfaces. The highest occupied molecular orbital and the lowest unoccupied molecular orbital of the heterojunctions distribute in the carbon nanotube section. As the band offsets of the above heterojunctions are achieved with the average bond energy method, the band structure is plotted.