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Background:Fucoidan is a complex sulfated polysaccharide extracted from brown seaweed and has a wide variety of biological activities. It not only inhibits cancer cell growth but also inhibits tyrosinase in vitro. Therefore, it is of interest to investigate the effect of fucoidan on B16 murine melanoma cells as the findings may provide new insights into the underlying mechanism regarding the inhibition of melanin formation by fucoidan. In the present study, we aimed to investigate the anti-melanogenic effect of fucoidan and its inhibitory effect on B16 cells. Materials and Methods: The influence of fucoidan on B16 melanoma cells and cellular tyrosinase was examined. Cell viability was examined by the cell counting kit-8 assay. Cellular tyrosinase activity and melanin content were determined using spectrophotometric methods and protein expression was analyzed by immunoblotting. Morphological changes in B16 melanoma cells were examined by phase contrast microscopy and apoptosis was analyzed by flow cytometry. Results: In vitro studies were performed using cell viability analysis and showed that fucoidan significantly decreased viable cell number in a dose-response manner with an IC50 of 550 ±4.3 μg/mL. Cell morphology was altered and significant apoptosis was induced when cells were exposed to 550 μg/mL fucoidan for 48 h. Conclusion: This study provides substantial evidence to show that fucoidan inhibits B16 melanoma cell proliferation and cellular tyrosinase activity. Fucoidan may be useful in the treatment of hyperpigmentation and as a skin-whitening agent in the cosmetics industry.

This paper presents nonlinear seismic response analysis of canyons in layered sites. The equivalent linear method is used in the dynamic analysis and Lysmer-Kuhlemeyer transmitting boundary is added at the left and right boundaries of the computation region. It is shown through numerical examples that, soil nonlinearity has significant effect on seismic ground motion around canyons. There are differences between seismic response amplitudes in nonlinear analysis and those in linear analysis, but the differences are smaller for observation points inside canyons. There are shifts between response spectra in nonlinear analysis and those in linear analysis, but the differences are much larger for observation points inside canyons.

This paper presents nonlinear amplification of seismic ground motion by twin cavities in layered sites. The equivalent linear method is used in the dynamic analysis and Lysmer-Kuhlemeyer transmitting boundary is used at the left and right boundaries of the computation region. It is shown that, cavities have significant effect on seismic ground motion, and soil nonlinearity has significant effect on seismic ground motion around cavities. The PGAs in linear and nonlinear analysis may be increased by 24.4% and 19.2%, compared with those in the free-field response. The PGA in nonlinear analysis may be decreased by 44.6%, compared with that in the linear analysis.

This paper studies nonlinear amplification of seismic ground motion by alluvial valley in layered sites. The equivalent linear method is used in dynamic analysis and transmitting boundaries are added at boundaries of the computation region. It is shown that, soil nonlinearity has significant effect on seismic ground motion around alluvial valley. The amplitudes in the case of linear alluvium and soil layers are the largest, those in the case of nonlinear alluvium and soil layers are the smallest, and those in the case of nonlinear alluvium and linear soil layers fall in between. The periods in the case of nonlinear alluvium and soil layers are the longest, those in the case of nonlinear alluvium and soil layers and those in the case of linear alluvium and linear soil layers are almost the same.

Using the pseudo-excitation method, a simple model was built to study the seismic response of buried pipeline laid through three-soil site for vertical incidence of seismic waves. Seismic ground motions are considered as stationary stochastic processes, and the cross-PSD function was established based on auto-PSD model, coherence model, and site response model. The results show that the peak bending stress depends on the properties of adjacent soils and the width of middle-soil, and appears in the pipeline near the soil interfaces.

Water distribution system is one of the most critical facilities in cities, and is more fragile compared with other structures. Losses in a water distribution system are often existed before health monitoring is implemented. This paper proposes to detect an existing local loss in a water distribution system on the basis of optimal monitoring of water pressure. The local loss is assumed at different positions with different extents, and pressures at monitoring stations is calculated, and the loss is then detected by minimizing the difference between the calculated and monitoring pressures at the monitoring stations. The efficiency is validated by example analysis. It is shown that an existing local loss is more reliably detected in a water distribution system with optimal monitoring.

In order to investigate the seismic behavior include hysteretic curve, skeleton curve and stiffness degradation, four masonry structures with different details are tested under pseudo-dynamic test and low cycle lateral load test. One kind of full-scale building is confined masonry with tie-column and ring-beam. Other is common brick masonry. Test results indicate that the tie-column and ring-beam play an important role for developing higher resistance and better deformability. And tie-column and ring-beam can effectively confined brick wall to improve the seismic performance of masonry structure. The stiffness degradation curves are similar. The stiffness degradation is modeled as a function of the effective stiffness and lateral displacement.

For further study on the influence of ground motion on the seismic performance of brick masonry structure, two masonry buildings were designed and constructed according to common structure style in towns and villages. Two full-scale buildings were subjected to different earthquake motion using pseudo-dynamic test. The earthquake motions are artificial earthquake motion and strong motion recording. This paper presents hysteretic behavior and deformation under horizontal seismic action. Crack propagation of masonry structure is analyzed. These tests verify that displacement response of masonry structures under different ground motion is pretty much the same. Tie-column and ring-beam can effectively confined brick wall. The cracks are mostly diagonal cracks caused by shear failure.

For further study on effective seismic design requirements of masonry structure, two masonry buildings were designed and constructed according to common structure style in towns and villages. Two full-scale buidings were subjected to earthquake using pseudo-dynamic test and quasi-static test. This paper presents crack propagation of masonry structure, hysteretic behavior, deformation and stiffness degradation under horizontal seismic action. In this experiment, deformability and ultimate bearing capacity of confined masonry (CM) with tie-column and ring-beam is higher than common brick structure (BM). Confined masonry (CM) wall maintain integrity due to constraint of tie-column and ring-beam. These tests verify that tie-column and ring-beam system is an effective seismic requirement to enhance seismic performance of masonry structure.

This paper presents a method for simulation of water distribution systems with breaks, in which, the leakage and low supply pressure can be considered. The effects of break location and extent on pressure variation of monitoring stations are simulated by numerical examples. It is shown that, the method can be used for estimating the effected area due to breaks; the high sensitivity may be achieved if monitoring stations are uniformly distributed; pressure variations are linear for small breaks and nonlinear for large ones.