Bubble Dynamics in a Narrow Rectangular Channel

It is very important to study the bubble dynamics in order to understand the physical process of boiling heat transfer in a narrow channel. Experimental and theoretical studies on bubble dynamics in a narrow rectangular channel are proposed. The cross section of the narrow rectangular channel is 2 mm × 8 mm. A high speed digital camera is applied to capture bubble behaviors from the narrow side and wide side of the narrow rectangular channel. Bubble growth rate, bubble departure diameter, bubble interface parameter and others are obtained according to the observation. A force balance analysis on a growing bubble is proposed to predict the bubble departure diameter and sliding bubble velocity, and the predicted results agree with the experimental data. Thus, the mechanism of bubble departure, slide and lift-off behavior in a narrow rectangular channel can be explained by the analysis of forces

Synergistic Antitumor Effect of Dichloroacetate in Combination with 5-Fluorouracil in Colorectal Cancer

Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been recently demonstrated as a promising nontoxic antineoplastic agent that promotes apoptosis of cancer cells. In the present study, we aimed to investigate the antitumor effect of DCA combined with 5-Fluorouracil (5-FU) on colorectal cancer (CRC) cells. Four human CRC cell lines were treated with DCA or 5-FU, or a combination of DCA and 5-FU. The cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The interaction between DCA and 5-FU was evaluated by the median effect principle. Immunocytochemistry with bromodeoxyuridine (BrdU) was carried out to determine the proliferation of CRC cells. Cell cycle and apoptosis were measured by flow cytometry, and the expression of apoptosis-related molecules was assessed by western blot. Our results demonstrated that DCA inhibited the viability of CRC cells and had synergistic antiproliferation in combination with 5-FU. Moreover, compared with 5-FU alone, the apoptosis of CRC cells treated with DCA and 5-FU was enhanced and demonstrated with the changes of Bcl-2, Bax, and caspase-3 proteins. Our results suggest that DCA has a synergistic antitumor effect with 5-FU on CRC cell lines in vitro