Dynamic Modeling and Sensitivity Analysis for an MEA-Based CO_(2) Capture Absorber

The absorber is the key unit in the post-combustion monoethanolamine(MEA)-based carbon dioxide(CO_(2))capture process.A rate-based dynamic model for the absorber is developed and validated using steady-state experimental data reported in open literature.Sensitivity analysis is performed with respect to important model parameters associated with the reaction,mass transport and phy-sical property relationships.Then,a singular value decomposition(SVD)-based subspace parameter estimation method is proposed to improve the model accu-racy.Finally,dynamic simulations are carried out to investigate the effects of the feed rate of lean MEA solution and the flue inlet conditions.Simulation results indicate that the established dynamic model can reasonably reflect the physical behavior of the absorber.Some new insights are gained from the simulation results.

Reversal mechanism of arsenic trioxide in the drug resistance of human gastric cancer cell line SGC7901/ADR

Objective： To investigate the reversal effect of arsenic trioxide （As2O3） on the multidrug resistance of human gastric tumor SGC7901/ADR cell line to adriamycin （ADM） and its reversal mechanisms, Methods： The non-cytotoxic concentration of As2O3 and the sensitivity of SGC7901/ADR cells toADM were detected by MTT assay, The drug concentration and P-gp function of SGC7901/ADR cells were measured with flow cytometry （FCM）, and the impacts of As2O3 on the GST-Π and Topo Ⅱ expressions of SGC7901/ADR cells were analyzed by immunohistochemical method. Results： As2O3 at 0,4 to 0.8 μmol/L concentrations were not significantly cytotoxic to SGC7901/ADR cells, As2O3 at 0.8 μmol/L could improve the sensitivity of SGC7901/ADR cells to ADM via inhibiting P-gp function, down-regulating GST-Π expression and increasing the intracellular accumulation of ADM in SGC7901/ADR cells. Conclusion： As2O3 can reverse partly the drug-resistance of SGC7901/ADR cells to ADM, which may be related with inhibiting the P-gp function and down-regulating GST-Π expression.

Upregulation of annexin A5 affects the biological behaviors of lung squamous carcinoma cells in vitro

Annexin A5 is a Ca2?-dependent phospholipidbinding protein and protein kinase C inhibitory protein. It has a potential role in cellular signal transduction, inflammation, growth and differentiation. In this study, we evaluated the expression of this protein in lung tumor tissues and subsequently established a NCI-H520 cell line that stably expresses the wild-type ANXA5 gene to determine the effects of annexin A5 upregulation on the cell morphology, proliferation and metastasis potential in vitro.The effects of annexin A5 on NCI-H520 cells were tested by crystal violet staining, CCK-8 assay, scratch wound assay, and Transwell assay. The expressions of Akt,PCNA, vimentin, and E-cadherin were examined by Western blot assay. In this study, we demonstrated that annexin A5 is expressed at lower levels in tumor tissues compared with normal tissues. Additionally, the upregulation of this protein may inhibit the proliferation, migration, and invasion abilities of NCI-H520 cells in vitro. The transfected cells were arrested in the G1/S phase of the cell cycle, and the expression levels of Akt, PCNA and Vimentin were downregulated, while E-cadherin was upregulated.

The Road to the Beijing Winter Olympics and Beyond: Opinions and Perspectives on Physiology and Innovation in Winter Sport

Beijing will host the 2022 Winter Olympics,and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport.Simultaneously,Government-directed initiatives aim to increase public participation in recreational winter sport.These parallel developments allow research to advance knowledge and understanding of the physiological determinants of performance and health related to winter sport.Winter sport athletes often conduct a substan-tial amount of training with high volumes of low-to-moderate exercise intensity and lower volumes of high-intensity work.Moreover,much of the training occur at low ambient temperatures and winter sport athletes have high risk of developing asthma or asthma-related conditions,such as exercise-induced bronchoconstriction.The high training volumes require optimal nutrition with increased energy and dietary protein requirement to stimulate muscle protein synthesis response in the post-exercise period.Whether higher protein intake is required in the cold should be investigated.Cross-country ski-ing is performed mostly in Northern hemisphere with a strong cultural heritage and sporting tradition.It is expected that innovative initiatives on recruitment and training during the next few years will target to enhance performance of Chinese athletes in classical endurance-based winter sport.The innovation potential coupled with resourcing and population may be substantial with the potential for China to become a significant winter sport nation.This paper discusses the physiological aspects of endurance training and performance in winter sport highlighting areas where innovation may advance in athletic performance in cold environments.In addition,to ensure sustainable development of snow sport,a quality ski patrol and rescue system is recommended for the safety of increasing mass participation.