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Pancreatic cancer is one of the leading causes of cancer-related death worldwide. Activating transcription factor 2 (ATF2) is a multifunctional transcription factor, and is implicated in tumor progress, yet its role in pancreatic cancer remains unclear. In the present study, the level of ATF2 in pancreatic cancer tissues and the adjacent non-tumorous tissues was detected by quantitative real-time PCR and Western blot. The roles of ATF2 in the proliferation, cell cycle, and apoptosis of pancreatic cancer cells were investigated through ATF2 silencing, and the effect of ATF2 shRNA on the sensitivity of pancreatic cancer cells to gemcitabine, an anti-tumor drug, was explored. The results of our study showed that the ATF2 level in the pancreatic cancer tissues was higher than that in the adjacent non-tumorous tissues. Silencing of ATF2 was found to inhibit proliferation, arrest cell cycle at G1 phase and induce apoptosis in pancreatic cancer cells. Moreover, ATF2 silencing enhanced gemcitabine-induced growth-inhibition and apoptosis-induction effects in pancreatic cancer cells. In summary, silencing of ATF2 inhibited the growth of pancreatic cancer cells and enhanced the anti-tumor effects of gemcitabine, suggesting that ATF2 plays a pro-survival role in pancreatic cancer. Our results also propose that a high level of ATF2 may serve as a potential biomarker of pancreatic cancer, and that ATF2 may become a potential target for anti-tumor therapy.

In this study, the impact of pancreatic cancer cell interaction with macrophages on the differentiation and function of macrophages and the behaviors of pancreatic cancer cells in vitro is evaluated. The expression of immunocompetent cell-associated markers in 22 pancreatic cancer specimens was characterized by immunohistochemistry. The impact of pancreatic cancer cells (PANC-1 and BxPC-3) on the differentiation and migration of human U937 monocytes and the effect of U937-derived macrophages on the proliferation and invasion of PANC-1 and BxPC-3 were determined by transwell assays. The potential effect on U937-derived macrophages or on the behaviors of pancreatic cancer cells following coculture in a transwell system was analyzed by quantitative real-time polymerase chain reaction. The high levels of macrophage-related CD68 and CD163 expression were detected in the pancreatic cancer specimens. Pancreatic cancer cells promoted the differentiation of U937 cells and migration of U937-derived macrophages, but decreased the mRNA transcripts of macrophage polarization-related genes of interleukin (IL)-10, IL-12p40, inducible nitric oxide synthase (iNOS), and CD163, particularly for iNOS. Furthermore, U937-derived M2 macrophages inhibited the proliferation of pancreatic cancer cells, but promoted their invasion. Coculture of pancreatic cancer cells with U937-derived macrophages upregulated the mRNA expression of genes associated with the epithelial-mesenchymal transition process, angiogenesis, and stemness of pancreatic cancer, but downregulated the expression of E-cadherin in pancreatic cancer cells. The interaction between pancreatic cancer cells and tumor-associated macrophages may play a pivotal role in the progression of pancreatic cancer.

The BN and BCNO phosphors were prepared at 750°C using different methods and their structure and luminescent properties were investigated. All the prepared samples were turbostratic boron nitride structure. The SEM and high-resolution TEM images show that the BCNO phosphors are polycrystalline in nature and include some nanocrystals. The carbon and oxygen impurities have great effects on the excitation, emission, and absorption spectra of BN and BCNO phosphors. The first-principle calculations results indicate that the carbon and oxygen impurities will produce energy levels in the band gap, which can affect the spectra properties of BCNO phosphors. The spectra properties of BN and BCNO phosphors can be well explained by a simplified energy level diagram.

Ammonium polyphosphate (APP) was encapsulated with boron-modified phenolic resin (BPF) by in situ polymerization with the goal of improving its hydrophobicity, thermal stability, and compatibility in polymers. The chemical and physical features of APP microcapsules were characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, scanning electron microscopy, inductively coupled plasma, and laser particle sizing. The hydrophobicity was assessed by the water contact angle. The residues from thermogravimetric analyzer and muffle burner were investigated. The results showed that the APP microcapsules with BPF shell had been achieved successfully. The shell encapsulation rate mainly depended on the amount of crosslinking agent when the ratio of APP/BPF was constant. The mean particle size increased and the particle size distribution became more narrow. The hydrophobicity of APP was improved and the improvement degree mainly depended on the amount and adding rate of crosslinking agent and the conditions of heat curing. A good thermal stability and high residue char rate at high temperature were noticed for APP microcapsules. It suggests that these microcapsules might be used as an intrinsic flame retardant. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43720.

Poly(arylene ether nitrile) (PEN) nanocomposites filled with functionalized graphite nanoplates (GNs) were prepared by a simple solution- casting method and then characterized by rheometer and thermogravimetric analysis (TGA). This study investigates how the surface treatment of GNs affects the GN dispersion state. The linear rheological test indicated that the 4-aminophenoxyphthalonitrile-grafted GN (GN-CN) presented better dispersion in PEN matrix than purified GN because the corresponding composite showed the lower rheological percolation threshold, which was further confirmed by scanning electron microscopy and solution experiments. The TGA revealed that the presence of 4-aminophenoxyphthalonitrile-grafted GN retarded the depolymerization evidently compared with that of purified GN, showing remarkable increase in the temperatures corresponding to a weight loss of 5 wt % (increased by 21°C) and maximum rate of decomposition (increased by 9°C). Both the dispersion state and the surface functionalization of GN are very important to the thermal stability of PEN matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

In this study, a novel multifunctional poly(arylene ether nitriles)(PEN)/carbon nanotubes/Fe3O4 nanocomposite with high tensile strength, magnetic, and electrical properties was investigated. First, we synthesized the monodisperse Fe3O4 nanoparticles on the surface of the multiwalled carbon nanotubes and then the hybrid material was compounded with PEN through the solution-casting method. The SEM and TEM images indicated that the monodisperse Fe3O4 nanoparticles, with the diameters of 70∼80 nm, were self-assembled along CNTs via the covalent bond method, which was confirmed by FTIR and XRD. The results of tensile properties showed that the tensile strength and modulus reached their highest values at the CNTs/Fe3O4 loading content of 1 wt % and both were greatly enhanced after heat treatment. Electrical conductivity of the polymer was dramatically enhanced at the low loading level of CNTs/Fe3O4; the electrical percolation of was in the range of 5∼8 wt % of CNTs/Fe3O4. The magnetic study showed that the saturation magnetization (Ms) of PEN/CNTs/Fe3O4 nanocomposites increased with the increase of CNTs/Fe3O4 loading content, and the coercive force (Hc) of the nanocomposite was independent of the CNTs/Fe3O4 content. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011

The processing of cross-linked polyarylene ether nitrile (PEN), which has a triazine rings structure, has been investigated under different reaction times and temperatures. In this study, the PEN films prepared by the tape-casting formed the thermally stable triazine rings by catalytic cross-linking reaction gradually, which was characterized by Fourier transform infrared spectroscopy. The chemical cross-linking reaction occurred as the CN group absorption of PEN at 2221 cm−1 decreased and a new absorption peak, at 1682 cm−1, was observed, and the absorption peak intensity would be progressively larger, with the extension of the processing time. After the formation of cross-linking networks, the cross-linking degree and thermal and mechanical properties of the processed films were improved substantially, compared with the untreated films. The film with added ZnCl2 as the catalyst was more rapidly cross-linked, and its properties were better than that without catalyst at the same treatment conditions. The glass-transition temperature (Tg) of PEN films processed at 350°C for 4 h (213.65°C) was higher than that of PEN films before the treatment (161°C), and the tensile strength was also improved significantly. The PEN was processed at 350°C for 2 h, whose initial decomposition temperature increases by about 10°C, compared with that of untreated film, at one time. The rheology behavior of the cross-linked films was processed on dynamic rheometer to monitor and track the process of polymer cross-linking reaction. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A new Mn-based Heusler alloy Mn2CuAl has been synthesized by the melt-spinning method. It has an ordered bcc structure and is a ferrimagnet with a saturation moment of 1.44 µB/f.u. at 5 K. The magnetization mainly comes from the contributions of the antiparallel aligned Mn spin moments. A compensation point is observed at 630 K, indicating the antiferromagnetism between the two Mn sublattices. The Curie temperature of the ribbons is 690 K. When heated to 740 K, the Mn2CuAl ribbons completely decompose to a mixture of a tetragonal phase and a Cu9Al4 phase.

Poly(arylene ether nitrile) (PEN) nanocomposites containing various functionalized multi-walled carbon nanotubes (MWCNTs) were prepared through a solution-casting method. The as-prepared PEN nanocomposites were investigated using parallel-plate rheometry and thermogravimetric analysis, aimed at examining the effect of surface functionalization on the dispersion of MWCNTs from the viscoelastic and thermal properties. The linear viscoelasticy results indicated that 4-aminophenoxyphthalonitrile-grafted MWCNTs presented better dispersion in the PEN matrix than purified and carboxylic MWCNTs because the corresponding composite showed the lowest rheological percolation threshold, which was further confirmed from scanning electron microscopy, dissolution experiments and solution rheological experiments. The thermogravimetric analysis results revealed that the presence of 4-aminophenoxyphthalonitrile-grafted and carboxylic MWCNTs retarded the depolymerization compared with purified MWCNTs, showing a marked increase in the temperature corresponding to a loss of 5 wt% (increased by 14–22 °C) and maximum rate of decomposition (increased by 4–8 °C). Both the state of dispersion and the surface functionalization of MWCNTs are very important to the thermal stability of the PEN matrix. Copyright © 2011 Society of Chemical Industry

Structure and magnetic properties of the Er3Fe29−xCrx compounds have been investigated by means of X-ray diffraction and magnetic measurements. It is found that all the Er3Fe29−xCrx compounds crystallize in a disordered Th2Ni17-type structure (space group P63/mmc) although the nominal atomic composition is 3:29. The lattice constants c increases and a decreases monotonically with increasing Cr content. When the Cr content increases, the Curie temperature Tc first increases, going through a maximum at around x = 2, then decreases. The saturation magnetization Ms decreases almost linearly with increasing Cr content. A first order magnetization process (FOMP) is observed for x = 2 and 3, the critical field Bcr of the FOMP is 4.52 T for x = 2 and 3.02 T for x = 3, respectively. All the compounds exhibit easy-plane type anisotropy at room temperature. The temperature dependence of the ac susceptibility measurement shows an anomaly at around 150 K, which is attributed to the temperature-induced domain wall movement under excitation of the external field for x = 0–3 and to a spin reorientation transition from the easy-plane type to the easy-axis type for x = 4, respectively. © 2005 Elsevier B.V. All rights reserved.