Simulation and research of chip-level micromixer with T-type based on ANSYS

A T-shaped chip-scale micromixer with built-in baffles is simulated and investigated based on ANSYS. This paper highlights on a comparative analysis of the effect of different numbers, rows, positions, angles and different Reynolds numbers (Re) of baffles on the mixing efficiency within a chip-scale micromixer. The simulation results demonstrate that: increase in the amount of baffles improved mixing of two fluids; the double rows of baffles significantly improve the mixing efficiency compared with the single rows of baffles; the position of the baffles relocates a certain distance to the outlet, which accelerates mixing of fluids in the chip-scale mixer; the mixing efficiency of baffle angle of 120° is also superior to that of 60°; the Re is between 0.1 and 2, which results in a high mixing efficiency; and the mixing efficiency slowly becomes lower when the Re is between 2 and higher mixing efficiencies with Re values between 0.1 and 2; Re between 2 and 40, the mixing efficiency slowly becomes lower; Re between 40 and 100, the mixing efficiency gradually rises

Comparison of Proliferation and Genomic Instability Responses to WRN Silencing in Hematopoietic HL60 and TK6 Cells

BACKGROUND: Werner syndrome (WS) results from defects in the RecQ helicase (WRN) and is characterized by premature aging and accelerated tumorigenesis. Contradictorily, WRN deficient human fibroblasts derived from WS patients show a characteristically slower cell proliferation rate, as do primary fibroblasts and human cancer cell lines with WRN depletion. Previous studies reported that WRN silencing in combination with deficiency in other genes led to significantly accelerated cellular proliferation and tumorigenesis. The aim of the present study was to examine the effects of silencing WRN in p53 deficient HL60 and p53 wild-type TK6 hematopoietic cells, in order to further the understanding of WRN-associated tumorigenesis. METHODOLOGY/PRINCIPAL FINDINGS: We found that silencing WRN accelerated the proliferation of HL60 cells and decreased the cell growth rate of TK6 cells. Loss of WRN increased DNA damage in both cell types as measured by COMET assay, but elicited different responses in each cell line. In HL60 cells, but not in TK6 cells, the loss of WRN led to significant increases in levels of phosphorylated RB and numbers of cells progressing from G1 phase to S phase as shown by cell cycle analysis. Moreover, WRN depletion in HL60 cells led to the hyper-activation of homologous recombination repair via up-regulation of RAD51 and BLM protein levels. This resulted in DNA damage disrepair, apparent by the increased frequencies of both spontaneous and chemically induced structural chromosomal aberrations and sister chromatid exchanges. CONCLUSIONS/SIGNIFICANCE: Together, our data suggest that the effects of WRN silencing on cell proliferation and genomic instability are modulated probably by other genetic factors, including p53, which might play a role in the carcinogenesis induced by WRN deficiency

Estimating the ecosystem service losses from proposed land reclamation projects: A case study in Xiamen

Economic valuation of ecosystem damages is an important building block in the development of full cost accounting which may lead to improvements in environmental policy making. Based on an analysis of the negative impacts of land reclamation on coastal ecosystem services and a review of different valuation techniques, this study develops a framework for selecting relevant valuation methods for different ecosystem services and for developing total ecosystem loss estimates for land reclamation projects. We illustrate the framework through a case study of Tong'an Bay, Xiamen, China where four reclamation schemes have been proposed. The results show that the costs associated with ecosystem damages are significantly higher than the internal costs of these reclamation projects.Land reclamation Coastal ecosystem services Ecosystem valuation Environmental damage Coastal management

Estimating the ecosystem service losses from proposed land reclamation projects: A case study in Xiamen

Economic valuation of ecosystem damages is an important building block in the development of full cost accounting which may lead to improvements in environmental policy making. Based on an analysis of the negative impacts of land reclamation on coastal ecosystem services and a review of different valuation techniques, this study develops a framework for selecting relevant valuation methods for different ecosystem services and for developing total ecosystem loss estimates for land reclamation projects. We illustrate the framework through a case study of Tong'an Bay, Xiamen, China where four reclamation schemes have been proposed. The results show that the costs associated with ecosystem damages are significantly higher than the internal costs of these reclamation projects. (C) 2010 Elsevier B.V. All rights reserved.National Natural Science Foundation of China [70771098