Search

Self-assembly of [Hg(SeCN)4]2- tetrahedral building blocks, iron(II) ions, and a series of bis-monodentate pyridyl-type bridging ligands has afforded the new heterobimetallic HgII-FeII coordination polymers {Fe[Hg(SeCN)3]2(4,4'-bipy)2}n (1), {Fe[Hg(SeCN)4](tvp)}n (2), {Fe[Hg(SeCN)3]2(4,4'-azpy)2}n (3), {Fe[Hg(SeCN)4](4,4'-azpy)(MeOH)}n (4), {Fe[Hg(SeCN)4](3,3'-bipy)}n (5) and {Fe[Hg(SeCN)4](3,3'-azpy)}n (6) (4,4-bipy = 4,4'-bipyridine, tvp = trans-1,2-bis(4-pyridyl)ethylene, 4,4'-azpy = 4,4'-azobispyridine, 3,3-bipy = 3,3'-bipyridine, 3,3'-azpy = 3,3'-azobispyridine). Single-crystal X-ray analyses show that compounds 1 and 3 display a two-dimensional robust sheet structure made up of infinite linear [(FeL)n]2n+ (L = 4,4'-bipy or 4,4'-azpy) chains linked by in situ formed {[Hg(L)(SeCN)3]2}2- anionic dimeric bridges. Complexes 2 and 4-6 define three-dimensional networks with different topological structures, indicating, in combination with complexes 1 and 3, that the polarity, length, rigidity, and conformation of the bridging organic ligand play important roles in the structural nature of the products reported here. The magnetic properties of complexes 1 and 2 show the occurrence of temperature- and light-induced spin crossover (SCO) properties, while complexes 4-6 are in the high-spin state at all temperatures. The current results provide a new route for the design and synthesis of new SCO functional materials with non-Hofmann-type traditional structures.

Background/Aims: Hepatocellular carcinoma (HCC) is one of the most common human malignant diseases in the world, and the mechanisms underlying HCC carcinogenesis and progression need further investigation. MicroRNAs play important roles in the development of cancer, and miR-500a is suggested to be deregulated in some types of cancer. However, the underlying molecular mechanisms of miR-500a in HCC remain unknown. Methods: The expression of miR-500a in HCC was analyzed in The Cancer Genome Atlas (TCGA) database and examined in 33 pairs of HCC tissues and matched nontumor tissues. The correlation between miR-500a expression and prognosis of HCC patients was analyzed from the survival data in TCGA. The mechanism of miR-500a upregulation in HCC was detected using chromatin immunoprecipitation-quantitative real-time PCR. The roles of miR-500a in HCC development were examined using a cell counting kit-8 assay in vitro and growth of transplanted tumors in nude mice in vivo. Apoptosis of HCC was detected using Annexin V/propidium iodide staining. The expression of BH3-interacting death agonist (BID) protein was examined using western blot analysis. Results: miR-500a expression was upregulated in HCC tissues, and high miR-500a expression was significantly correlated with the poor prognosis of HCC patients. Histone modifications in the promoter region of miR-500a may be responsible for its increased expression. Inhibition of miR-500a in HCC cell lines significantly promoted apoptosis, as well as inhibiting the proliferation of HCC cells and growth of transplanted tumors in nude mice. miR-500a directly targeted the 3′ untranslated region of BID mRNA, and inhibition of miR-500a-promoted apoptosis was almost completely abolished by the administration of ABT-199 via the BID-mitochondria pathway. Conclusion: Our results suggest that histone modifications in the promoter region of miR-500a may be responsible for the increased expression of miR-500a in HCC, which promotes cancer progression by targeting BID, indicating that miR-500a may be a potential prognostic predictor and therapeutic target for HCC patients.

Homogeneous RuCl2(PPh3)3 and RhCl(PPh3)3 complexes were heterogenized on amine functionalized MCM-41. The heterogeneous ruthenium and rhodium complexes were used for catalytic upgrading of bio-oil under mild conditions (50–90°C). Both showed good activity in the hydrogenation of aldehydes and phenols with C=C side chains in bio-oil. The stability and properties of the bio-oil improved significantly. By comparison, the heterogenized rhodium catalyst was more effective than the ruthenium catalyst. Moreover, the catalysts still showed good activity after three reaction cycles. The results demonstrated that the utilization of heterogenized homogenous metal complexes was a promising treatment for upgrading bio-oil.

Cadium sulfide/titanium dioxide (CdS/TiO2) catalyst was prepared by two different methods: microemulsion-mediated solvothermal hydrolyzation (CdS/TiO2 (SH)) and in-situ sulfurization under supercritical conditions (CdS/TiO2 (SS)). The photocatalysts were characterized by nitrogen adsorption-desorption, X-ray diffraction, X-ray photoelectron spectra, UV-Vis absorption spectra, and PL spectra. Photodegradation reactions of three monomeric and one dimeric lignin model compounds, and kraft pine lignin (Indulin AT) were carried out at room temperature in a weak alkaline aqueous system by visible light irradiation with air bubbling. Quantitative results showed that these lignin model compounds and kraft lignin were effectively degraded. While both phenolic and non-phenolic lignin units are reactive, the phenolic units appeared to react faster and preferentially reacted.

A modified hydrothermal carbonization (HTC) process in the presence of borax was developed to produce uniform and monodispersed micro-carbon spheres. Corn starch was used as carbon precursor and borax acts as a structure directing agent. The introduction of borax could catalytically transform the starch into hydroxymethylfurfural (HMF) and favoring the rapid nucleation and slow growth of particle owing to the buffer function of borax additive. The inclusion of borax thus allowed for the controlling of particles morphology as well as tailoring the particle diameters. Uniform solid carbon spheres with a narrow particle size distribution, ranging from 0.6 to 2 μm, was demonstrated by turning the borax concentration and the reaction time in a single-step hydrothermal process. The retained boron content and chemical structure of the carbonaceous products could be adjusted as revealed by inductively coupled plasma (ICP) and Fourier transformed infrared (FTIR) analysis. Furthermore, the boron-dopant increased the final product's thermostability from 536 °C to 629 °C at 0.70 wt% boron content. This method therefore also provides a facile and novel approach to prepare boron-doped carbon materials.

Pd/TiO 2 was prepared for photocatalytic degradation of bio-oil's oligomers. The catalyst was characterized by X-ray photoelectron spectra, photoluminescence spectra, UV–Vis diffuse reflectance spectra and transmission electron microscopy. Quantitative results were obtained from gas chromatography/mass spectrometry. The results demonstrated that the main products were esters, such as methyl hexadecanoate, dibutyl phthalate and bis(2-ethylhexyl)phthalate. The effect of initial concentration of oligomers, temperature and mass of catalyst were also researched in our work.

A method of ultrasound-assisted reduction of a nickel-ammonia complex with borohydride in aqueous solution was used to prepare NiMoB/MCM-41 and NiMoB/SBA-15 supported amorphous alloy catalysts. These catalysts were used to upgrade bio-oil at mild temperatures ranging from 100 to 160 °C and recycling of these two supported catalysts and of unsupported NiMoB was carried out. Then, fresh and third time used catalysts were characterized by X-ray diffraction, X-ray photoelectron spectra, and transmission electron microscopy. Quantitative results were obtained from the analysis of gas chromatography/mass spectrometry. Through mild upgrading, 1-hydroxy-2-propanone, furfural, and 2-methoxy-4-vinylphenol in the bio-oil were converted to relevant alcohols and saturated phenols. The conversion rates were 45.7, 71.5, and 57.1 %, respectively, when crude bio-oil was upgraded using NiMoB/MCM-41 at 160 °C. The two supported catalysts, especially NiMoB/MCM-41, had smaller amorphous NiMoB particles and exhibited more uniform dispersion on mesoporous silica, leading to higher reaction activity and stability than unsupported NiMoB. Deactivation of these catalysts resulted from the reduction of Ni0, B0, and Mo4+ species on the surface, the transition from the amorphous to the crystalline state, particle agglomeration, and coke deposition on the surface.

Zinc porphyrins and its analogs showing many excellent properties such as good potosensitivity, non-toxicity, high stability and facile preparation attract more and more attention of scientists. Here, a novel zinc porphyrazine, namely zinc(II) tetracarboxyl- tetra(1,4-dithiin) porphyrazine [abbreviated as ZnPz(dtn-COOH)4] was successfully synthesized and its potocatalytic activity was studied. The ZnPz(dtn-COOH)4 supported on an Amberlite CG-400 resin was used as a biomimetic catalyst for the activation of molecular oxygen under visible light to degrade a probe dye compound Rhodamine B (RhB) in aqueous solution. Interestingly, the mechanism for the oxidative degradation of RhB involves both 1O2 and HO (Type II and Type I mechanisms, respectively). More hydroxyl radicals were produced at pH 3, which was responded for the highest degradation ratio. The catalyst can be reused several times without losing its catalytic activity, with an average RhB degradation ratio around 80% for 12 h. The most probable mechanism of RhB degradation in this study was that N,N-diehyl-N-ethyl-rhodamine was the main intermediate, which was then cleaved to small molecule by reactive oxidizing species. This study demonstrated a promising approach for the activation of molecular oxygen by the newly developed biomimetic catalyst, in which the central metal to be unchangeable valence, for environmental remediation and oxidation catalysis.

The exact mechanisms underlying inhibitory effects of pioglitazone (Pio) on Angiotensin II (AngII)-induced atrial fibrosis are complex and remain largely unknown. In the present study, we examined the effect of Pio on AngII-induced mice atrial fibrosis in vivo and atrial fibroblasts proliferation in vitro. In vivo study showed that AngII infusion induced atrial fibrosis and increased expressions of Toll/IL-1 receptor domain-containing adaptor inducing IFN-β (TRIF) and tumor necrosis factor receptor associated factor 6 (TRAF6) in mice models. However, those effects could be attenuated by Pio (P