Increasing evidence suggests that gut microbiota underpin the development of health and longevity. However, our understanding of what influences the composition of this community of the longevous has not been adequately described. Therefore, illumina sequencing analysis was performed on the gut microbiota of centenarians (aged 100-108 years; RC) and younger elderlies (aged 85-99 years; RE) living in Bama County, Guangxi, China and the elderlies (aged 80-92 years; CE) living in Nanning City, Guangxi, China. In addition, their diet was monitored using a semiquantitative dietary questionary (FFQ 23). The results revealed the abundance of Roseburia and Escherichia was significantly greater, whereas that of Lactobacillus, Faecalibacterium, Parabacteroides, Butyricimonas, Coprococcus, Megamonas, Mitsuokella, Sutterella, and Akkermansia was significantly less in centenarians at the genus level. Both clustering analysis and UniFraq distance analysis showed structural segregation with age and diet among the three populations. Using partial least square discriminate analysis and redundancy analysis, we identified 33 and 34 operational taxonomic units (OTUs) as key OTUs that were significantly associated with age and diet, respectively. Age-related OTUs were characterized as Ruminococcaceae, Clostridiaceae, and Lachnospiraceae, and the former two were increased in the centenarians; diet-related OTUs were classified as Bacteroidales, Lachnospiraceae, and Ruminococcaceae. The former two were deceased, whereas the later one was increased, in the high-fiber diet. The age and high-fiber diet were concomitant with changes in the gut microbiota of centenarians, suggesting that age and high-fiber diet can establish a new structurally balanced architecture of gut microbiota that may benefit the health of centenarians.

The effects of borax on the setting time, compressive strength, bond strength, drying shrinkage and pH value were investigated for potassium magnesium phosphate cement (MKPC). The results show that with the increase of borax dosage, the setting time is gradually extended, both compressive strength and bond strength are greatly decreased, the drying shrinkage rate is increased. Especially high dosage of borax, the extension of setting time is more obvious. Compared with that without borax, when the dosage of borax is 12.5%, setting time can be prolonged by 214.8%.The influence of borax dosage on the time-dependent effect of compressive strength shows that when the dosage of borax is 2.5%~5.0%, compressive strength increases rapidly from 4h to 1d, and increases relatively slowly from 1d to 3d. When borax dosage is less than 2.5% or higher than 5%, the law of time-dependent effect of compressive strength is the opposite. Compared to borax prior to magnesia addition, the pH value of the system is larger and the time of inflection point is advanced when borax and magnesia are mixed together at the same time. The increase of borax dosage can reduce the pH value of the system, and decrease the rising rate of pH value, at the same time the required time when the final pH value is relatively stable is longer.

This paper deals with the effect of mineral admixtures and Geopolymer on preventing excessive expansion due to alkali-silica reaction (ASR). The test method used was ASTM C 441-97. Expansions of mortar-bars were measured at 14, 56, 90 days. The results prove that mineral admixtures can effectively restrain ASR. When three kinds of mineral admixtures, silica fume, fly ash, and ground granulated blast-furnace slag (GGBS), were used together, they bring about a compound effect which is more effective to restrain ASR. Mortar expansion can be reduced 81.9 % by this compound effect. Chemical analysis of the pore solution shows that mineral admixtures reduced concentrations of hydroxyl, potassium and sodium ion, so that damages from ASR decreases. Geopolymer, an amorphous inorganic material, was prepared with metakaolin and other mineral admixtures in the condition of high pH. Alkalis fixed in the framework of Geopolymer, there are no enough alkalis to react with active aggregates. Geopolymer does not generate any dangerous alkali-silica reaction even with alkali contents as high as 12.1 %.

For the first time, a new kind of polycarboxylic acid high-performance water reducer, with ultra-high water reducing performance, was prepared through one-step polymerization, using new type polyether TPEG and acrylic acid as raw materials. Maximum water-reducing ratio of TPC may reach 50%. The most distinguishing characteristic of TPC was its reaction character at normal temperatures (30°C), which was of great practical significance for energy conservation and pollution reduction.

Using esterification-polymerization two-steps synthesis method, two kinds of comb-like polycarboxylate agents of BT and JS were synthesized by controlling acid-ester ratio. The adsorption characteristics of Ca2+ions on comb-like polycarboxylate polymers in the CaCl2solution were studied. The results indicated that the adsorption behavior was closely related to the structure of polymers, the adsorption power of JS with water-reducing structure was strong, while weak with slump loss resisting polymers BT. The adsorption behavior was also in connection with the acid-ester ratio of polymer structure, the higher the acid-ester ratio is, the greater the absorption power; On the contrary, it will be smaller.

Comb-shaped hyper-branched polycarboxylate polymers, both water-reducing-type admixtures (applied in cement, symbol of JS) and slump-retaining-type admixtures (applied in cement, symbol of BT), were prepared, and their adsorption characteristics with SO42- ions were studied by conductivity loss experiments. The results indicated that both JS and BT generate electrical conductivity losses in Na2SO4 aqueous solutions, suggesting that there was some interaction adsorption between the SO42- ions and the polymer. The adsorption was closely related to the pH of the sample solutions and occurred due to the strong interactions between the carboxylic acid groups in the polymer backbones and SO42- ions (rather than Na+ ions). However, there was an extremely weak electrostatic adsorptive interaction between the SO42- ions and the long polyether side-chain.

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Comb-shaped hyper-branched polycarboxylate admixture polymers, both the water-reducing-type JS and slump-retaining-type BT, were prepared, and their adsorption characteristics with Ca2+ions were studied by conductivity loss experiments. The results indicated that, both the water-reducing-type JS and slump-retaining-type BT, would generate certain electrical conductivity loss in CaCl2aqueous solutions, suggesting that there was some close adsorption between the polymer and Ca2+ions, the adsorption was closely related with the pH value of the polymers, the neutral and alkaline samples neutralized by NaOH show an higher adsorption than that non-neutralized. The adsorption was achieved by the strong interaction between carboxylic acid groups in the polymer backbones and Ca2+ions (rather than Cl-ions)