Direct Synthesis of Partially Chain-Straightened Propylene Oligomers and P-MA Co-Oligomers Using Axially Flexible Shielded Iminopyridyl Palladium Complexes.

In this study, a series of partially chain-straightened propylene oligomers and functional propylene−methyl acrylate (P-MA) co-oligomers were synthesized with 8-alkyl-iminopyridyl Pd(II) catalysts. The molecular weight and polar monomer incorporation ratio could be tuned by using Pd(II) catalysts with various 8-alkyl-naphthyl substituents (8-alkyl: H, Me, and n-Bu). In propylene oligomerization, all the 8-alkyl-iminopyridyl Pd(II) catalysts convert propylene to partially chain-straightened (119−136/1000 C) oligomers with low molecular weights (0.3−1.5 kg/mol). Among the catalysts, Pd1 with non-substituent (H) on the ligand showed the highest activity of 5.4 × 104 g/((mol of Pd) h), generating oligomers with the lowest molecular weight (Mn: 0.3 kg/mol). Moreover, polar-functionalized propylene-MA co-oligomers with very high incorporation ratios (22.8−36.5 mol %) could be obtained in the copolymerization using these 8-alkyl-iminopyridyl Pd(II) catalysts. Additionally, Pd1 exhibited the best performance in propylene-MA copolymerization as it displayed the highest MA incorporation ratio of up to 36.5 mol%. All the three catalysts are capable of generating partially chain-straightened P-MA co-oligomers and the activities decrease gradually while the molecular weight increases with the increasing steric hindrance of the alkyl substituent (H < Me < n-Bu). Compared to Pd4 with the rigid 8-aryl substituent, the flexible 8-alkyl-iminopyridyl Pd(II) catalysts (Pd1-3) not only showed much higher activities in the propylene oligomerization, but also yielded P-MA co-oligomers with significantly higher incorporation ratios in the propylene co-oligomerization.

The different expression of caspase-1 in HBV-related liver disease and acts as a biomarker for acute-on-chronic liver failure.

BACKGROUND: Caspase-1 is an evolutionarily conserved enzyme that proteolytically cleaves the precursors of the inflammatory cytokines interleukin 1ß and interleukin 18. However, the role of caspase-1 in determining the severity of acute-on-chronic liver failure (ACLF) has yet to be elucidated. We evaluated the expression levels of caspase-1 in HBV-related liver disease and assessed its utility as a biomarker predicting the severity of ACLF. METHODS: The gene, protein and activity levels of caspase-1 were measured in the liver and/or serum of subjects with HBV-related disease. We also analysed the correlation between the expression levels of caspase-1 and liver injury of ACLF. RESULTS: Compared with the values observed in normal subjects, the relative caspase-1 mRNA and protein levels in livers were decreased in patients with CHB, LC, and HCC but increased in those with ACLF; moreover, ACLF patients had the lowest serum level and hepatic activity of caspase-1 among the five groups. The serum caspase-1 levels in ACLF patients showed a negative correlation with total serum bilirubin and a positive correlation with serum total protein and albumin. Importantly, the serum caspase-1 levels in the surviving group with ACLF were higher than those in the non-surviving group and showed different dynamic trends. Analyses of the area under the receiver operating characteristic curve indicated that caspase-1 (AUC = 0.84, AUC of MELD score = 0.72) may be a useful marker for independently predicting ACLF. CONCLUSION: Caspase-1 is a potential non-invasive biomarker of disease progression and prognosis in ACLF.

Regioselective oxyalkylation of vinylarenes catalyzed by diatomite-supported manganese oxide nanoparticles.

A regioselective oxyalkylation reaction of vinylarenes with cyclic ethers was developed under the catalysis of a new heterogeneous catalyst, the diatomite-supported Mn(3)O(4) nanoparticles (SMONP-1). The use of this heterogeneous catalyst provided a novel approach for the synthesis of α-carbonyled ß-alkylated aryl derivatives via a sp(3) C-H bond functionalization under mild aerobic conditions.