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In this study, the multifaceted properties of hyaluronic acid (HA) were used for the targeted therapy of cancer by photodynamic therapy (PDT) guided by molecular imaging. Near-infrared (NIR) photosensitizers (Chlorin e6; Ce6) were encapsulated into poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) coated with HA that can act as CD44 targeting ligand. The abundant carboxylate groups of HA also enabled the chelation of gadolinium ions (Gd 3+ ), T1-weighted MRI contrast agents, on the surface of PLGA NPs. Through both in vitro and in vivo fluorescence and MRI signal analysis, we confirmed that the HA-Gd-Ce6-PLGA NPs (HAGCP-NPs) could efficiently target CD44-overexpressing A549 cancer cells. When an NIR laser was illuminated to irradiate A549 tumor-bearing mice, the groups treated with HAGCP-NPs showed remarkable delays in tumor growth or tumor regression. Taken together, the HAGCP-NPs are expected to be used as a theranostic platform for the dual modal (MR/NIR) imaging and PDT of cancer. [ABSTRACT FROM AUTHOR]

Abstract: Precursor films based on poly(vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) and P(VDF-TrFE) blended with Pb(Zr,Ti)O3 were spin-coated on Si-substrates and subsequently annealed at 170°C. X-ray diffraction studies showed that the amorphous precursor films crystallize to the γ-phase P(VDF-TrFE) without involving the formation of other polymorphs when the P(VDF-TrFE) is blended with Pb(Zr,Ti)O3, resulting in phase mixtures composed of a crystalline γ-phase P(VDF-TrFE) and an amorphous Pb(Zr,Ti)O3. A larger memory window width and higher accumulation capacitance, as well as a lower leakage current density are induced by the blended Pb(Zr,Ti)O3 within the low operating voltage ranges from −3.0 to 3.0V and from −2.0 to 2.0V for 20wt% and 40wt% Pb(Zr,Ti)O3 blending, respectively. These improvements not only in the hysteretic capacitance–voltage characteristics but also in the leakage current density–electric field are directly correlated with the phase mixtures, their volume fraction, dipole moments, and formation of interface layer between the blended film and Si substrate. [Copyright &y& Elsevier]

Single-cell microarrays may play an important role in understanding the heterogeneity of cell populations. A hydrogel-coated micropatterned surface was prepared to capture single cells from a mixture of cells and detect their mitochondrial activity using real-time fluorescence analysis. The double-layered hydrogel micropatterns were functionalized with RGD-containing peptides using a photomask. We were able to control the number of cells immobilized on each spot of the micropattern by controlling the size of the spots. Single cells were properly arranged on the peptide-functionalized spot with aligned squares (20 μm × 20 μm), with 68% frequency of single cells. In the single-cell micropattern, a mitochondria-targetable switch-on-type of probe was employed to discriminate between the types of cells and exhibit heterogeneous cell behavior in real-time. This single cell detection technology allows for the analysis of cell function and gene expression in various environments. [Display omitted] • We fabricated single-cell microarrays on a PEG hydrogel-coated surface, allowing real-time analysis of single cells. • Single cells were properly arranged on the peptide-functionalized spot in pattern, with 68% frequency. • A mitochondria-targetable was employed to discriminate between the types of cells and exhibit heterogeneous cell behavior. • The mitochondrial activity was monitored by fluorescence analysis using a single cell array. • The signals from MDA-MB-231 cells showed a stronger red intensity, whereas NIH-3T3 cells exhibited a weaker red intensity. [ABSTRACT FROM AUTHOR]

This paper focuses on the degradation behavior of ethylene vinyl acetate (EVA) and Al-doped ZnO (AZO) films in CIGS PV modules after the damp heat test. We observed losses of the FF and efficiency in the modules after 1000 h of damp heat (DH) exposure and some of them were discolored from the outside edge and the center. To clarify the degradation behavior of the non-discolored and discolored modules, a failure analysis for each position of the EVA and AZO in the CIGS module films from the edge to the center was performed. The resistivity of the AZO films in the non-discolored modules increased due to the adsorption of oxygen. In discolored modules, the resistivity of the AZO films rapidly increased at the edge region, and the morphologies of the AZO films were also changed due to the chemical degradation of EVA. These degradation behaviors of the AZO films and EVA in discolored modules were attributed to the formation of hydroxyl and carboxylic species caused by water penetration. Moreover, we reported that the transmittance and the mechanical properties of EVA after 1000 h DH exposure were deteriorated by water molecules. [ABSTRACT FROM AUTHOR]

This paper characterizes and compares the degradation mechanisms of Cu(In,Ga)Se 2 (CIGS)-based thin film photovoltaic (PV) modules during exposure to damp heat (85 °C/85% RH) for 1000 h and thermal cycling (−40 °C/85 °C) for 1000 cycles. After damp heat (DH) exposure, the efficiency of the PV modules was reduced from the initial value of ∼12.5 ± 0.1% to 10.5 ± 0.2% due to increase of the resistivity in the AZO and CIGS layers. The optical band gap was also decreased from the initial value of 3.60 eV–3.54 eV after 1000-h DH exposure. This behavior was associated with oxygen adsorption and the generation of hydroxides in the AZO layer. The efficiency of the PV modules after subjection to thermal cycling (TC) was decreased to 11.4 ± 0.2% due to increase of the resistivity of the AZO and CIGS layers. The increase in the resistivity was interpreted as being due to oxygen adsorption, as well as the formation of micro-cracks in the AZO films. [ABSTRACT FROM AUTHOR]

Abstract: For the successful commercial production of CIGS PV modules, a good long-term damp heat stability of solar modules is necessary. The causes for the degradation of encapsulated solar modules are clearly explained. This article investigates the degradation behavior of encapsulated CIGS PV modules combined with the failure analysis of AZO films in CIGS cells. CIGS PV modules were exposed to the damp heat test of the IEC 61646 qualification standard—the modules are discolored from the outside edge to the center. Moreover, each module had its own distinct discolored area. The discolored area of the modules is significantly associated with the degradation of FF and efficiency. To clarify the causes of the degradation of FF and efficiency, failure analysis of AZO films in CIGS cells was performed. Electrical and structural properties as well as observation of the microstructure depending on the position of the AZO layers were characterized to explain the degradation mechanism of the encapsulated CIGS PV modules. It was revealed that the discoloration phenomenon of the modules and the degradation of AZO films were caused by the penetration of water molecules and adsorption of oxygen. By XPS and FT-IR analyses, the causes of degradation were confirmed. It was attributed to the generation of Zn(OH)2 and carboxylic acids by a combination of EVA, AZO and water molecules. [Copyright &y& Elsevier]