The synergistic combinations of organic polymers for separation applications with inorganic substances such as multi-walled carbon nanotubes (MWNTs), have resulted in a new class of membrane material ...called mixed matrix membrane (MMM) for the separation of CO
2/CH
4 gases. Mixed matrix membrane incorporated functionalized MWNTs (f-MWNTs) were fabricated by the solution casting method, in which the f-MWNTs were embedded into the polyimide membrane and the resulting membranes were characterized. The effect of nominal MWNTs content between 0.5 and 1.0
wt% on the gas separation properties was investigated. The mixed matrix membranes showed 100% enhancement for the selectivity of CO
2/CH
4 compared to the corresponding neat polymer membrane. This new class of mixed matrix membrane has the ability to separate gases at the molecular level and has the potential to ultimately reduce the energy consumed in present-day separation operations. This study has shown that addition of CNTs to polymeric membranes has improved separation properties of the membranes to a certain extent.
Autophagy is a lysosomal degradation process of redundant or faulty cell components in normal cells. However, certain diseases are associated with dysfunctional autophagy. Rapamycin, a major ...immunosuppressant used in islet transplantation, is an inhibitor of mammalian target of rapamycin and is known to cause induction of autophagy. The objective of this study was to evaluate the in vitro and in vivo effects of rapamycin on pancreatic β cells. Rapamycin induced upregulation of autophagy in both cultured isolated islets and pancreatic β cells of green fluorescent protein–microtubule‐associated protein 1 light chain 3 transgenic mice. Rapamycin reduced the viability of isolated β cells and down‐regulated their insulin function, both in vitro and in vivo. In addition, rapamycin increased the percentages of apoptotic β cells and dead cells in both isolated and in vivo intact islets. Treatment with 3‐methyladenine, an inhibitor of autophagy, abrogated the effects of rapamycin and restored β‐cell function in both in vitro experiments and animal experiments. We conclude that rapamycin‐induced islet dysfunction is mediated through upregulation of autophagy, with associated downregulation of insulin production and apoptosis of β cells. The results also showed that the use of an autophagy inhibitor abrogated these effects and promoted islet function and survival. The study findings suggest that targeting the autophagy pathway could be beneficial in promoting islet graft survival after transplantation.
This study shows that the upregulation of autophagy mediated by rapamycin treatment results in a significant impairment of cell insulin function, which may contribute to islet graft dysfunction observed in islet recipients.
We reported recently the clinical efficiency of interferon (IFN)-α/5-fluorouracil (5-FU) combination therapy in advanced hepatocellular carcinoma (HCC). However, prediction of the response to the ...combination therapy remains unsatisfactory. The aim of this study was to investigate the anti-tumour effects of microRNA (miR)-21 on the sensitivity of HCC cells to IFN-α/5-FU and whether miR-21 can be used as a predictor of the response to such therapy in HCC.
Changes in the sensitivity of HCC cells (PLC/PRF/5 and HepG2) to IFN-α/5-FU were examined after transfection with pre-miR-21 or anti-miR-21. The correlation between miR-21 expression level, evaluated by qRT-PCR, and response to the therapy was also investigated in clinical HCC specimens.
Hepatocellular carcinoma cells transfected with pre-miR-21 were significantly resistant to IFN-α/5-FU. Annexin V assay showed that the percentage of apoptotic cells was significantly lower in cells transfected with pre-miR-21 than control cells. Transfection of anti-miR-21 rendered HCC cells sensitive to IFN-α/5-FU, and such sensitivity was weakened by transfection of siRNAs of target molecules, PETN and PDCD4. miR-21 expression in clinical HCC specimens was significantly associated with the clinical response to the IFN-α/5-FU combination therapy and survival rate.
The miR-21 in HCC cell lines and clinical HCC samples is a significant modulator of the anti-tumour effect of IFN-α and 5-FU. This suggests that miR-21 is a potentially suitable marker for the prediction of the clinical response to the IFN-α/5-FU combination therapy.
Sputtering has been well-developed industrially with singular ambient gases including neutral argon (Ar), oxygen (O2), hydrogen (H2) and nitrogen (N2) to enhance the electrical and optical ...performances of indium tin oxide (ITO) films. Recent preliminary investigation into the use of combined ambient gases such as an Ar+O2+H2 ambient mixture, which was suitable for producing high-quality (low sheet resistance and high optical transmittance) of ITO films. To build on this promising preliminary work and develop deeper insight into the effect of ambient atmospheres on ITO film growth, this study provides a more detailed investigation of the effects of ambient combinations of Ar, O2, H2 on sputtered ITO films. Thin films of ITO were deposited on glass substrates by DC magnetron sputtering using three different ambient combinations: Ar, Ar+O2 and Ar+O2+H2. The structural, electrical and optical properties of the three ambient sputtered ITO films were systematically characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectroscopy, four probe electrical conductivity and optical spectroscopy. The XRD and Raman studies confirmed the cubic indium oxide structure, which is polycrystalline at room temperature for all the samples. AFM shows the minimum surface roughness of 2.7 nm for Ar+O2+H2 sputtered thin film material. The thickness of the films was determined by the cross sectional SEM analysis and its thickness was varied from 920 to 817 nm. The columnar growth of ITO films was also discussed here. The electrical and optical measurements of Ar+O2+H2 ambient combinations shows a decreased sheet resistance (5.06 ohm/□) and increased optical transmittance (69%) than other samples. The refractive index and packing density of the films were projected using optical transmission spectrum. From the observed results the Ar+O2+H2 ambient is a good choice to enhance the total optoelectronic properties of the ITO films. The improved electrical and optical properties of ITO films with respect to the Ar+O2+H2 ambient sample were discussed in detail. In addition, the physical properties were also discussed with the influence of this ambient combination with respect to Ar, Ar+O2 and Ar+O2+H2.
There are a lot of design problems of control system which are expressed as a performance index minimization under BMI conditions. However, a minimization problem expressed as LMIs can be easily ...solved because of the convex property of LMIs. Therefore, many researchers have been studying transforming a variety of control design problems into convex minimization problems expressed as LMIs. This paper proposes an LMI method for a quadratic performance index minimization problem with a class of BMI conditions. The minimization problem treated in this paper includes design problems of state-feedback gain for switched system and so on. The effectiveness of the proposed method is verified through a state-feedback gain design for switched systems and a numerical simulation using the designed feedback gains.
An insulating polymer, radiation vulcanization natural of rubber latex (RVNRL), was successfully converted into electrically conductive nanocomposite by the addition of reduced graphene oxide (rGO) ...assisted by sodium 1,4-bis(neopentyloxy)-3-(neopentyloxycarbonyl)-1,4-dioxobutane-2-sulfonate (TC14) surfactant. The starting material, graphene oxide (GO), was initially synthesized by electrochemical exfoliation assisted by TC14 surfactant. Then, GO/RVNRL nanocomposite was fabricated by latex technology. For rGO/RVNRL nanocomposite, the synthesized GO was further reduced to rGO using hydrazine hydrate and showed electrical enhancement up to 1.32 × 10
−3
S cm
−1
compared with GO when composited with RVNRL (8.64 × 10
−4
S cm
−1
). For comparison, rGO/RVNRL nanocomposite assisted by the commercially available surfactant sodium dodecyl sulfate was prepared, and its electrical conductivity was found to be 1.79 × 10
−5
S cm
−1
, which was several orders of magnitude lower than those of GO/RVNRL and rGO/RVNRL nanocomposites prepared with TC14 surfactant. C–V measurements taken for TC14-rGO/RVNRL and TC14-GO/RVNRL nanocomposites showed specific capacitances of 95 and 63 F g
−1
, respectively. The structural properties of nanocomposites were characterized using FESEM, HRTEM, UV–Vis, micro-Raman, XRD, FT-IR spectroscopy, and TGA studies. This study was the first to report on the success of converting the insulator polymer RVNRL into a conductive nanocomposite assisted by TC14 surfactant. The nanocomposite can be a new electrode material for supercapacitor application.
We report trapping and recombination centers with an acceptor-like character VZn and their defect complex in unintentional hydrogen-doped ZnO nanoparticles using photoluminescence and electron ...paramagnetic resonance (EPR) techniques. Further, we demonstrate the existence of a VZn–H complex defect related to local vibrational modes (LVMs) by Raman spectroscopy. EPR measurement confirms the characteristics of an uncompensated donor and acceptor under UV illumination in addition to the existence of multiple trapping centers even when the samples are subjected to high-temperature annealing; some of the LVMs related to VZn–H complex defect still persist with less intensity due to high thermal stability. Hydrogen bonding with native defect in ZnO lattice and their charge states are found to play a crucial role in achieving the donor and acceptor characteristics.
The identification of molecular markers useful for predicting prognosis in pancreatic cancer patients is crucial for advances in disease management. The epithelial cell adhesion molecule (Ep-CAM) is ...known to express in most epithelial malignancies and was reported as a tumor marker or a candidate of molecular targeting therapy. However, the clinical significance of Ep-CAM expression in pancreatic cancer is not well-known. We determined the difference of malignant potential between parental and Ep-CAM-transfected pancreatic cancer cell lines by using proliferation, invasion and migration assay. Furthermore, we determined the relationship between tumoral Ep-CAM expression of resected specimens and clinical prognosis in 95 pancreatic cancer patients receiving radical surgery at two different cancer centers. One of the three Ep-CAM-transfected cell lines showed significantly low proliferation rate compared with the parental cell, while there was no difference in the other two cell lines. In invasion and migration assays, Ep-CAM-transfected cells showed significantly lower malignant potential than parental in all of the three cell lines. In 95 pancreatic cancer patients, 47 patients showed high-Ep-CAM expression, while 48 patients showed low, and there was no difference of clinicopathological features between Ep-CAM high and low-expression group. High-Ep-CAM expression group showed significantly good prognosis in overall survival (3-year survival; 56.2 versus 19.2%, P=0.0018) as well as in disease-free survival (3-year survival; 40.3 versus 14.4%, P=0.038) compared with low-expression group. In addition, the impact of Ep-CAM was observed strongly in LN-negative group when the influence of Ep-CAM was examined with dividing patients into LN-positive and negative group. In multivariate analysis, Ep-CAM expression was one of the independent prognostic factors as well as histology and lymph node metastasis. Ep-CAM expression was found to be related to the suppression of pancreatic cancer cell activity and the good prognosis in pancreatic cancer patients receiving the curative resection.
Systematic investigation on the fabrications of vertically aligned carbon nanotubes (VACNTs) and zinc oxide (ZnO) nanocomposites for two different configurations were performed to enhance the field ...electron emission (FEE) performance of the VACNTs synthesised from waste chicken fat. FEE tests demonstrated improvement with the addition of ZnO nanostructures under the VACNT array, where the emission current increased from 212.85 to 259.80μAcm−2, while the turn-on field reduced from 2.66 to 1.60Vμm−1. Meanwhile, the growth of ZnO nanostructures on top of the VACNTs array resulted in a tremendous increase in emission current of up to 2090.00μAcm−2 and a decrease in the turn-on field to 0.49Vμm−1. The difference in the FEE improvement by different composite configuration reflects the significant role of the composite order. The improvement of FEE is influenced by the geometrical shape of the emitters as well as tunnelling effect of electrons through the structure of nanocomposite.
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•Zinc oxide enhances field emission of carbon nanotube from waste chicken fat precursor.•Two different configurations of nanocomposite were introduced.•Zinc oxide on top of carbon nanotube: turn-on field: 0.49Vμm−1•Zinc oxide under carbon nanotube array: turn-on field: 1.60Vμm−1
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