Idiopathic pulmonary fibrosis (IPF) is a progressive, eventually fatal disease characterized by fibrosis of the lung parenchyma and loss of lung function. IPF is believed to be caused by repetitive alveolar epithelial cell injury and dysregulated repair process including uncontrolled proliferation of lung (myo) fibroblasts and excessive deposition of extracellular matrix proteins in the interstitial space; however, the pathogenic pathways involved in IPF have not been fully elucidated. In this study, we attempted to characterize metabolic changes of lung tissues involved in the pathogenesis of IPF using gas chromatography-mass spectrometry-based metabolic profiling. Partial least-squares discriminant analysis (PLS-DA) model generated from metabolite data was able to discriminate between the control subjects and IPF patients (R(2)X = 0.37, R(2)Y = 0.613 and Q(2) (cumulative) = 0.54, receiver operator characteristic AUC > 0.9). We discovered 25 metabolite signatures of IPF using both univariate and multivariate statistical analyses (FDR < 0.05 and VIP score of PLS-DA > 1). These metabolite signatures indicated alteration in metabolic pathways: adenosine triphosphate degradation pathway, glycolysis pathway, glutathione biosynthesis pathway, and ornithine aminotransferase pathway. The results could provide additional insight into understanding the disease and potential for developing biomarkers.

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We report the thermal and electrical bistable characteristics of ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE) (72∕28mol%)] thin films as a function of varying memory device architectures. Rectangular-shaped capacitance-voltage (C-V) hysteresis loops obtained using 100nm P(VDF-TrFE) films with a metal-ferroelectric-insulator-semiconductor (MFIS) diode architecture were more suitable for distinguishing the data-bit state compared with the symmetrical hysteresis observed using metal-ferroelectric-metal capacitors. Poly(4-vinyl phenol) used as a dielectric insulator in the MFIS prevented shifting of the C-V hysteresis curve toward the negative bias voltage.