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The utilization of slag as an alternative to Portland cement in producing alkali-activated slag concrete (ASC) contributes to environmental protection. Replacement of freshwater and river sand by seawater and sea sand in concrete production is meaningful to island construction. Thus, the intention of this paper is to analyze the mechanical properties of ASC mixed by seawater and sea sand. Four types of ASC are prepared by considering the effects of seawater, sea sand and combination of the two constituents, respectively. Based on the SEM (scanning electron microscope) and XRD (X-ray diffraction) analysis, the seawater and sea sand are found to have some effect on the morphology and hydration products of the ASC. Therefore, the strengths of the four ASC are close to each other. The ASC with seawater or sea sand has slightly higher drying shrinkage but better resistance to chloride ion permeability. Moreover, bond performance of FRP (fiber-reinforced polymer) and steel bars to ASC is studied using pull-out tests. The short-term bond strength, interfacial shear rigidity and shear fracture energy of steel bars with ASC are apparently higher than those of FRP bars with ASC. But the ratios of the residual frictional stress to the bond strength are larger for the FRP bars. The bond strength and residual frictional stress in the ASC with sea water or sea sand are slightly higher and the largest shear fracture energy is observed in the ASC with the combination of sea water and sea sand.

Objective This study aims to detect the predominant bacteria in acute periapical abscesses of primary teeth using culture-independent molecular methods based on 16S ribosomal DNA cloning. Methods Purulent material was collected from nine children diagnosed with abscesses of endodontic origin. DNA was extracted and the 16S rRNA gene amplified with universal primer pairs 27F and 1492R. Amplified genes were cloned, sequenced by Applied Biosystems, and identified by comparison with known 16S rRNA gene sequences. Results Bacterial DNA was present in all nine purulence samples. A total of 681 clones were classified into 8 phyla, 78 genera, and 125 species/phylotypes. The phyla were Firmicutes, Proteobacteria, Fusobacteria, Bacteroidetes, Actinobacteria, Tenericutes, Deinococcus-Thermus, and Spirochaetes. The most dominant genera were Streptococcus (13.3%), Fusobacterium (11.8%), Parvimonas (7.8%), Prevotella (6.7%), Sphingomonas (5.8%), and Hafnia (5.2%). Fusobacterium nucleatum (11.5%), Parvimonas micra (7.8%), Streptococcus intermedius (6.6%), Sphingomonas echinoides (5.3%), Hafnia alvei (5.2%), and Citrobacter freundii (4.9%) were the most common species/phylotypes. Among these species/phylotypes, F.nucleatum was the most prevalent (7/9). C. freundii, Carnobacterium maltaromaticum, and H. alvei were seldom detected species in acute periapical abscesses but had relatively high abundance and prevalence. Conclusion Acute periapical abscesses are polymicrobial with certain prevalent bacteria, especially anaerobic bacterium. The most predominant and prevalent bacteria of acute periapical abscesses in children was F. nucleatum.

Purpose Denaturing gradient gel electrophoresis (DGGE) was used to investigate the bacterial communities associated with asymptomatic and symptomatic pericoronitis. The aim of the study was to compare the fingerprinting patterns of these 2 clinical conditions. Materials and Methods The microbiota of mandibular third molar pockets associated with asymptomatic or symptomatic pericoronitis cases were collected and profiled by the polymerase chain reaction DGGE method. Banding patterns were compared by cluster analysis techniques. Results Thirteen symptomatic pericoronitis and 7 asymptomatic pericoronitis samples were collected. Comparative analysis of the 2 clinical conditions showed bands that were common to the symptomatic and asymptomatic cases, but most DGGE bands appeared to be unique to the clinical condition. No single band occurred in all profiles. The mean number of bands detected in the 16S rDNA community profiles was 23.8 ± 4.2 (range, 19 to 34) for samples from symptomatic cases and 24.1 ± 2.4 (range, 21 to 29) for those from asymptomatic cases. Cluster analysis and multidimensional scaling analysis of the DGGE banding pattern showed a distinction in the similarity of banding patterns according to the presence or absence of symptoms. Conclusions These results suggest that the diversity of pericoronal pocket microbiota in asymptomatic pericoronitis cases differs markedly from that of symptomatic cases.

It is known that complexes of the multi-protein, gingipain, possess heme binding domains (hemagglutinin 2, HA2) that bind hemoglobin to provide heme and iron to the bacterium, Porphyromonas gingivalis. The DHYAVMISK peptide sequence was proposed to act as an inhibitor of hemin binding, and thus, it might be used to control or prevent periodontal disease. In this study, we created a monoclonal antibody (mAb) that targeted the DHYAVMISK peptide, aimed to determine whether it could inhibit the growth of P. gingivalis in vitro, and block its induction of experimental periodontitis and subsequent bone loss. Peptide DGFPG-DHYAVMISK conjugated to KLH (DK-KLH) was synthetic, and injected subcutaneously into BALB/c mice to generate specific mAbs with the hybridoma technique. We isolated mAb 1H11, which showed specific binding to DK. When we incubated these mAbs with P. gingivalis in vitro for 18 h, bacterial growth was significantly lower in cultures treated with mAb 1H11 compared to those treated with control (PBS; P 0.05). Next, we induced experimental periodontitis in mouse models with a silk ligature and a P. gingivalis infection. When we injected the mAbs into the gingival sulcus, the group treated with mAb 1H11 displayed a reduction in bone loss compared to the other treatment groups. Thus, mAb 1H11 might provide protection against a P. gingivalis infection. Accordingly, this antibody could serve as a candidate therapy for periodontitis or other infections caused by P. gingivalis.

Purpose Previous research has little specific guidance on how to improve large infrastructures’ risk analysis. This paper aims to propose a practical risk analysis framework across the project lifecycle with Bayesian Networks (BNs). Design/methodology/approach The framework includes three phases. In the qualitative phase, primary risks were identified by literature reviews and interviews; questionnaires were used to determine key risks at each project stage and causal relationships between stage-related risks. In the quantitation, brainstorming and questionnaires, and techniques of ranked nodes/paths, risk map and Bayesian truth serum were adopted. Then, a BN-based risk assessment model was developed, and risk analysis was conducted with AgenaRisk software. Findings Twenty key risks across the lifecycle were determined: some risks were recurring and different risks emerged at various stages with the construction and feasibility most risky. Results showed that previous stages’ risks significantly amplified subsequent stages’ risks. Based on the causality of stage-related risks, a qualitative model was easily constructed. Ranked nodes/paths facilitated the quantification by requiring less statistical knowledge and fewer parameters than traditional BNs. As articulated by a case, this model yielded very simple and easy-to-understand representations of risks and risk propagation pathways. Originality/value Rare research has developed a BN risk assessment model from the perspective of project stages. A structured model, a propagation network among individual risks, stage-related risks, and the final adverse consequence, has been designed. This research provides practitioners with a realistic risk assessment approach and further understanding of dynamic and stage-related risks throughout large infrastructures’ lifecycle. The framework can be modified and used in other real-world risk analysis where risks are complex and develop in stages.

A quiet revolution might now be observed internally in Chinese universities, along with emergence of a group of experimental colleges/schools. These experimental units showcase a bottom-up approach to exercising democratic governance, whereby many grassroots initiatives could be identified and brought into the practices, and they are more likely to tap autonomous practices into existing operations, often in a genuine and innovative way.

Porphyromonas gingivalis (P. gingivalis) is a major etiological agent in the development and progression of chronic periodontitis. It produces cysteine proteases (gingipains), including a lysine-specific gingipain and two arginine-specific gingipains. Heme binding and uptake are fundamental to the growth and virulence of P. gingivalis. The recombinant hemagglutinin 2 domain (rHA2) of gingipain binds hemin with high affinity. The aim of the present work was to identify the key residues involved in its hemin-binding activity. A functional rHA2 was expressed and bound to hemin-agarose, and then digested with endopeptidases. The peptides bound to hemin-agarose were identified by mass spectrometry and the amino acids were assessed by mutation and peptide binding inhibition analysis. The DHYAVMISK sequence was identified in peptides derived from both Asp-N and Lys-C endopeptidase digestions of rHA2. A monoclonal antibody, mAb QB, was produced and its epitope was associated with the DGFPGDHYAVMISK peptide within the HA2 domain. Hemin was shown to competitively inhibit the immunoreactivity of rHA2 or the peptide to mAb QB. The peptide DHYAVMISK inhibited hemin-binding activity; although, this inhibition was not seen when the peptide contained the H1001E mutation (DEYAVMISK). Based on these results, we propose that residue His1001 is involved in the hemin-binding mechanism of the P. gingivalis rHA2 and the peptide containing this residue, DHYAVMISK, may be an inhibitor of hemin binding.

Based on the spin-polarization theory of ferromagnetism of Hirsch and taking the electron-phonon interaction into account, we study the effect of electron-phonon interaction on the spontaneous magnetization m(s) of metallic hydrogen at zero temperature. It is shown that the lattice vibration not only reduces m(s), but also narrows the area of m(s) not equal 0.