Designing prepacked aggregate concrete for improved mechanical properties and its field application in constructing steel tube concrete.

Prepacked aggregate concrete (PAC) is made by placing coarse aggregates of various sizes into a formwork and then filling the voids between coarse aggregate and grout. The mechanical performance of PAC is dominated by the compactness due to grout filling, but few study considered the pouring methods and grout performance synchronously. The coupled effect of pouring methods and grout performance on the compactness of PAC is investigated in this study. The results show that the gravity pouring method is only suitable for grouts with good flowability. The pump pouring method is more widely used. It can be adapted to grout with poorer fluidity and coarse aggregate with greater apparent density. The ultrasonic pulse velocity test method provides a relatively accurate evaluation of the compactness of PAC. Furthermore, due to the enhanced mechanical properties of PAC, the filed application potential in the preparation of steel tube concrete columns has also been confirmed, where the results exhibited that PAC based steel tube concrete contributed to an enhanced ductility and autogenous shrinkage.

Rhodium-Catalyzed Three-Component Reaction of Alkynes, Arylzinc Chlorides, and Iodomethanes Producing Trisubstituted/Tetrasubstituted Alkenes with/without 1,4-Migration.

A three-component reaction of alkynes, arylzinc chlorides, and iodomethanes was found to proceed in the presence of a rhodium catalyst to give high yields of trisubstituted/tetrasubstituted alkenes. The usual arylzinc chlorides only gave trisubstituted alkenes, generated through a migratory carbozincation-cross-coupling sequence, where 1,4-Rh migration from an alkenyl carbon to an aryl carbon occurred. In contrast, 5-membered heteroarylzinc chlorides only gave the tetrasubstituted alkenes via a carborhodation-cross-coupling pathway without 1,4-migration.

Rhodium-Catalyzed Desymmetric Arylation of γ,γ-Disubsituted Cyclohexadienones: Asymmetric Synthesis of Chiral All-Carbon Quaternary Centers.

The desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an (R)-segphos-rhodium catalyst gave high yields of the corresponding cyclohexenones, which contain a chiral arylated carbon center at the ß-position and a chiral all-carbon quaternary center at the γ-position, with high diastereo- and enantioselectivities. This catalytic system was also applied to the arylation of spirocarbocyclic cyclohexadienones and afforded the corresponding cyclohexenones bearing a chiral spiro quaternary carbon with high dr and ee.

Synthetic galactomannans with potent anti-HIV activity.

Ring-opening polymerization of a new 1,6-anhydro disaccharide monomer, 1, 6-anhydro-2, 3-di-O-benzyl-4-O-(2', 3', 4', 6'-tetra-O-benzyl-α-d-galactopyranosyl)-α-d-mannopyranose, was carried out using PF5 as a catalyst under high vacuum at -60°C to give galactose branched mannopyranan (synthetic galactomannan), 4-O-α-d-galactopyranosyl-(1→6)-α-d-mannopyranan, after debenzylation with Na in liquid NH3. The ring-opening copolymerization with 1, 6-anhydro-tri-O-benzyl-α-d-mannopyranose in various feeds was also performed to give synthetic galactomannans with various proportions of galactose branches. After sulfation, sulfated synthetic galactomannans were found to have anti-HIV activity and cytotoxicity as high and low as those of standard curdlan and dextran sulfates, respectively, which are potent anti-HIV sulfated polysaccharides with low cytotoxicity. The anti-HIV mechanism of sulfated synthetic galactomannans used by poly-l-lysine as a model peptide of the HIV surface protein was estimated by using SPR, DSL, and zeta potential measurements, revealing the electrostatic interaction between negatively charged sulfate groups and positively charged amino groups.

Correlation between miR-23a and onset of hepatocellular carcinoma.

BACKGROUND AND AIMS: To clarify the role of miR-23a in the onset and development of hepatocarcinoma on the cellular, genetic and molecular levels. PATIENTS AND METHODS: Seventy-eight patients were included after hepatectomy. Relationships between the clinical pathological factors of tumor and paracancerous tissues were analyzed. Risk factors of overall and recurrence-free survival rates were subject to multi-variable analysis. Tissues were sequenced by digital miRNA expression profiling, and new miRNA was subject to target gene prediction. RESULTS: miR-23a expression was correlated with the stage of the TNM Classification of Malignant Tumours most significantly, followed by tumor size (P=0.041 and 0.047). High miR-23a, vascular invasion, tumor size≥7cm, tumor capsule and late pathological stage were the risk factors of overall survival rate, and those of recurrence-free survival rate also included alpha-fetoprotein level≥200µg/L and multiple tumors. Compared with normal hepatic cell line L-02, the miR-23a expression levels in tumor cell lines SMMC-7721 and HepG2 were up-regulated and down-regulated respectively. Transfecting miR-23a inhibitor suppressed cell growth. Apoptotic rates of the control and those transfected with inhibitor-NC and miR-23a inhibitor for 48h were similar. CONCLUSION: High miR-23a expression is the independent prognostic factor of overall and recurrence-free survival rates, and miR-23a may be involved in the onset of hepatocarcinoma as an oncogene.