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The current codes in practice define fatigue load models (FLMs) to characterize the bridge damage that is induced by traffic loads. However, most FLMs are specified to load on any single traffic lane, and the characteristics of the uneven traffic load distribution over multiple lanes under real-world conditions are not revealed. This study analyzed the uneven distribution characteristic of truck loading over multiple lanes based on multiple sets of weigh-in-motion (WIM) data and investigated its effect on the fatigue performance of bridges. A novel multi-lane FLM is proposed, comprising a standard fatigue truck model and multi-lane fatigue coefficients. The standard fatigue truck model is the same as FLM II of the Chinese design specification; however, the load value is adjusted using a calibrated coefficient correlated with the bridge length. The multi-lane fatigue coefficients help define the reduction coefficients for the load value and number of fatigue cycles when applying the standard fatigue truck model to a certain traffic lane. Finally, the proposed model and the code-based model are applied to evaluate the fatigue performance of typical steel–concrete composite girder bridges, and the results are compared with the estimations using realistic multi-lane WIM data. The proposed model yields similar estimations of the stress range and fatigue life as using WIM data, whereas the code-based model shows large deviations. The comparisons validate the feasibility and superiority of the proposed multi-lane FLM for the fatigue evaluation of bridges under uneven multi-lane truck loadings.

It is difficult to develop BaTiO 3 -based ceramics with enhanced electrical properties and temperature stability simultaneously. In this regard, Er-modified Ba(Zr 0.05 Ti 0.95 )O 3 (BZT-Er) ceramics were designed and synthesized to solve the above problem. The effect of Er 2 O 3 on the microstructure, phase transition, piezoelectric, electromechanical performance and thermal stability of BZT piezoceramics were systemically explored. It was shown that the addition of Er 2 O 3 hardly influences the phase structure of BZT ceramics, which was confirmed by the XRD, Raman and dielectric measurements. The optimized piezoelectric and electromechanical performance is achieved for the BZT-0.04Er ceramics with d 33 of 253pC/N and S max / E max of 368 pm/V, respectively, along with no deterioration of the thermal stability. Consequently, the improvement in piezoelectric, electromechanical and thermal stability was realized simultaneously in BZT-Er ceramics. These observations indicate that the Er-modified BZT ceramics can be deemed as one of the hopeful candidates for actual applications, showing remarkable figure of merit.

In this study, the effect on the terahertz (THz) transmission characteristics was investigated by varying the constant magnetic field time at both ends of the liquid sample (deionized water, CuSO4, CuCl2, (CH3COO) 2Cu, Na2SO4, NaCl, CH3COONa solution). The results show that the transmission intensity of THz waves decreases with the increase of solution residence time in a constant magnetic field. It is inferred that the magnetic field increases the number of hydrogen bonds in the solution, enhances the role of hydrogen bonds, and weakens the intensity of THz transmission spectra.

This paper presents a case study of a large ground collapse (30.6 m long, 25.5 m wide, and 6.0 m deep) and water inrush and mud outburst (10540.8 m3) in the Qingdao line 4, China. This disaster caused a loss of life and property, and construction delay. After the catastrophe, the remedial measures had to be taken to guarantee the stability of the tunnels when tunnel advance resumed. Based on the geological survey and numerical modelling, the main causes of this disaster were summarized as the low strength of strata, high water pressure, stress concentration, the coupling interaction between seepage force and ground and, as a consequence, also the crash of the slice of strongly weathered tuff. Eventually, potential energy, which was derived from the collapse bodies, was transformed into kinetic energy and developed this disaster. After this disaster, a set of remedial instruments including filling the ground cave-in, reinforcing the advance core ahead of tunnel face, and conducting the porepoles to form a protective shell were proposed. After the tunnel advance resumed, these remedial instruments validated by employing monitoring data were effective to tackle this disaster.

High-entropy nitride (HEN) ceramics have recently been investigated for potential high-temperature structural application. Several single-phase HENs as well as their mechanical properties have been reported in the literature. However, an understanding of their mechanical properties at the atomic level is still lacking. In this work, density functional theory calculations are used to calculate the stacking fault energy on the {111} and {110} planes in rock salt structure (Ti,Zr,Nb,Ta)N. It is found that, in are 1 1 ‾ 0 > { 110 } and 1 1 ‾ 0 > { 111 } slip systems, the stacking fault energies generally agrees the rule of mixture values of the four mononitride components. For 11 2 ‾ > { 111 } slip system, the stacking fault energies cannot be perfectly described by a rule of mixture. The overall trend is dominated by the behavior of TaN and NbN, which have strong tendency for nucleation of intrinsic stacking faults. We also found that the energy fluctuation caused by atomic randomness in HENs is much smaller than the stacking fault energy barrier in all the slip systems.

The pathogenesis of Candida-associated stomatitis involves the dysfunction of flora antagonistic to Candida. Oral Actinomyces species play an important role in regulating the oral microecological balance. The objective of this study was to investigate the antagonism of three oral Actinomyces against Candida albicans.Suspensions, culture supernatants and bacterial lysates of Actinomyces viscosus, Actinomyces naeslundii and Actinomyces odontolyticus were investigated for their actions upon C. albicans. In addition to a commercial strain, six clinical strains of C. albicans were also tested. The proliferation of C. albicans was assessed using a liquid co-cultivation assay. The adhesion, acid protease and extracellular phospholipase activity, hyphae growth, and biofilm formation of C. albicans were measured.The results showed that the suspensions, culture supernatants and cell lysates of 10(8) colony forming units/ml oral Actinomyces significantly inhibited the proliferation of C. albicans (all P0.001). The culture supernatants exhibited significant antagonistic interactions in terms of adhesion (A. viscosus P0.001, A. naeslundii P=0.016 and A. odontolyticus P=0.009), acid protease (A. viscosus P=0.035, A. naeslundii P=0.022, A. odontolyticus P0.001) and phospholipase activities (A. viscosus P=0.011, A. naeslundii P=0.042, A. odontolyticus P=0.021) of Candida, as well as its hyphae growth (A. viscosus P=0.002, A. naeslundii P=0.008, A. odontolyticus P=0.006). Inhibition of C. albicans biofilm formation was also observed.This study provides preliminary evidence that oral Actinomyces have inhibitory effects on the proliferation, adhesion, metabolic enzyme activity, hyphae formation and biofilm development of C. albicans.

This study evaluated the efficacy of implant supported dental restorations in patients with chronic periodontal diseases at various stages within 2 years of completing treatment. 30 patients with periodontal diseases and 30 patients without periodontal diseases were studied. Total counts of 276 implant bodies were divided into group A (patients with periodontal diseases; a total of 149 implants) and group B (patients with healthy periodontium; a total of 127 implants). In group A subjects, periodontitis was treated prior to implant placement. The study focused on patients' modified sulcus bleeding index, modified plaque index, implant mobility index, periodontal probing depth and implant success rate 12 and 24 months after the completion of the treatment. The result show: there were no significant differences in implant success rate between groups A and B; modified sulcus bleeding index scores showed differences between the groups 24 months after treatment; there were no significant differences in other clinical indexes during the study between the groups; there were no significant differences in periodontal probing depth between the groups; modified plaque index and modified sulcus bleeding index were positively correlated in implant supported dental restoration patients with chronic periodontal diseases.

To establish human periodontal ligament stem cells (hPDLSC) with high and stable expression of enhanced green fluorescent protein (eGFP) and to obtain an ideal vector expression system that suitable for gene therapy in periodontal tissue engineering.hPDLSCs were transfected with eGFP for 48h via different MOI (25, 50, 100, 200 and 400) by lentiviral vector, the transfection efficiency was evaluated by fluorescent microscopy and flow cytometry, and transfected hPDLSCs proliferation was evaluated by MTT. Pluripotent, differentiation capacity and ALP expression status were determined further. Osteoblast-associated genes expressions for osteogenesis were evaluated by quantitative-PCR. In addition, rat molar periodontal fenestration defect model was used for evaluating periodontal tissue engineering.The transfection efficiency after 48h were 44.7%, 60.9%, 71.7%, 85.8%, and 86.9% respectively. There was no significant effect of transfection (at different MOI levels of 25, 50, 100, and 200) on the proliferation of hPDLSCs (designated as eGFP-hPDLSCs) compared with hPDLSCs (P0.05). However, proliferation of eGFP hPDLSCs at MOI 400 became slower (P0.05). Both eGFP hPDLSCs and hPDLSCs were able to differentiate into osteocytes and adipocytes under certain conditioned media. At 7 days, expression levels of COL-1, RUNX2 in hPDLSCS were higher than those in eGFP hPDLSCs (P0.05); expression levels of ALP and OPN in eGFP hPDLSCs were similar to those in hPDLSCs (P0.05). Newly regenerated bone formation was observed in the defect model used.Among the transfection conditions, 48h transfection at MOI 200 is optimal for labelling hPDLSCs with eGFP in a lentiviral vector. There is no change in capability of the eGFP hPDLSCs osteogenesis. The lentiviral vector with eGFP is an appropriate expression vector system and hPDLSCs are ideal seeding cells for gene therapy in periodontal tissue engineering.