Nanofluidic sustainable energy conversion using a 1D nanofluidic network.

We propose a 1-dimensional (1D) nanofluidic energy conversion device by implementing a surface-patterned Nafion membrane for the direct energy conversion of the pressure to electrical power. By implementing a -200-nm-thick nano-bridge with a 5-nm pore size between two microfluidic channels, we acquired an effective streaming potential of 307 mV and output power of 94 pW with 0.1 mM KCI under pressure difference of 45 MPa. The experimental results show both the effects of applied pressure differences and buffer concentrations on the effective streaming potential, and are consistent with the analytical prediction.

Elevated activities of MMP-2 in the non-tumorous lung tissues of curatively resected stage I NSCLC patients are associated with tumor recurrence and a poor survival.

BACKGROUND AND OBJECTIVES: We wanted to assess whether the level of enzyme activity for a particular matrix metalloproteinase (MMP), and not the amount of expressed protein, in lung tissue could be used as a reliable prognostic biomarker for tumor recurrence leading to poorer survival in a certain subgroup of patients who have undergone curative resection for stage I human NSCLC. METHODS: We determined what type of MMP was significant for tumor recurrence by using a mouse model of pulmonary metastasis with inoculating the footpad with H460 human cancer cells. We then looked for any association between tumor recurrence and the level of enzyme activities for the selected MMP in the tumor and also in the pathologically non-tumorous tissues from 34 stage I lung cancer patients. RESULTS: We obtained H460/PM6 cells having a highly metastatic potential after six repeated cycles of pulmonary metastasis by using the mouse footpad inoculated with the metastasized cancer cells in the previous cycle. We started with human lung cancer cells, H460, and we found that among the tested MMPs we tested for, the level of MMP-2 mRNA was elevated. No significant difference was seen in the level of enzyme activity of the MMP-2 cells from the curatively resected tumor tissues of the stage I NSCLC patients who were later found with or without recurrence. However, the level of MMP-2 enzyme activity was found to be significantly different between the non-tumorous lung tissues from patients later found with and without recurrence, and it was associated with the 5-year survival rate. CONCLUSIONS: This observation suggests that the higher level of MMP-2 enzyme activity in the non-tumorous tissues from the patients could be used as a prognostic biomarker to predict post-operative tumor recurrence and survival for patients with stage I NSCLC. The elevated enzyme activity of MMP-2 in the non-tumorous tissue resected from stage I NSCLC could be used as a prognostic indicator for post-operative tumor recurrence and the patients' poor survival. Further, this could be an important aid for physicians' making decision on whether to subject particular patients to post-operative adjunct chemotherapy.

Prognostic significance of E-cadherin and beta-catenin in resected stage I non-small cell lung cancer.

OBJECTIVES: E-cadherin and its associated intracellular molecules, catenins, are important for cell-cell adhesion. Impaired expression of these molecules are frequently observed in several cancers. E-cadherin and beta-catenin are often expressed in non-small cell lung cancers. The aim of this study was to investigate the expressions of E-cadherin and beta-catenin and their significance as prognostic markers in pathological stage I non-small cell lung cancer. METHODS: Paraffin embedded tumor tissue blocks were obtained from 141 patients who underwent resection without preoperative radiotherapy or chemotherapy with pathological stage I non-small cell lung cancer. Tumor samples were prepared in tissue microarrays and they were stained by immunohistochemistry with antibodies against E-cadherin and beta-catenin. The expressions of E-cadherin and beta-catenin were analyzed with relation to the clinico-pathological data. The median follow-up period of the patients was 41 months (range, 2-88 months). RESULTS: Preserved expressions of E-cadherin and beta-catenin were observed in the membrane and the cytoplasm of normal epithelial cells and tumor cells. Absent or reduced expression for E-cadherin and beta-catenin were observed in 60% and 45% of all the patients, respectively. There was a significant positive correlation between E-cadherin and beta-catenin expression (P<0.01). Absent or reduced expression of E-cadherin was observed in 72.5%, 36.6%, and 60.0% of squamous cell carcinoma, adenocarcinoma, and bronchioloalveolar carcinoma, respectively. There was a significant decrease of E-cadherin expression in squamous cell carcinoma compared to adenocarcinoma (P<0.01). Patients with reduced expression of beta-catenin had poor recurrence free survival in adenocarcinoma, but not in squamous cell carcinoma. CONCLUSION: Decreased expressions of E-cadherin and beta-catenin were closely correlated in resected stage I non-small cell lung cancer. Reduced expression of E-cadherin and beta-catenin indicates tumor cell dedifferentiation and reduced expression of beta-catenin had poor recurrence free survival in adenocarcinoma of the resected stage I non-small cell lung cancer.