synthesis-testing-supported-pt-cu-solid-solution-nanoparticle

Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation

A convenient method for the synthesis of bimetallic Pt-Cu catalysts and performance tests for propane dehydrogenation and characterization are ...

Purdue University

The multi-channel visible bremsstrahlung measurement system has been developed on Experimental Advanced Superconducting Tokamak (EAST). In addition to providing effective ion charge Zeff as a routine diagnostic, this diagnostic can also be used to estimate other parameters. With the assumption that Zeff can be seen as constant across the radius and does not change significantly during steady state discharges, central electron temperature, averaged electron density, electron density profile, and plasma current density profile have been obtained based on the scaling of Zeff with electron density and the relations between Zeff and these parameters. The estimated results are in good coincidence with measured values, providing an effective and convenient method to estimate other plasma parameters.

Application of visible bremsstrahlung to Z(eff) measurement on the Experimental Advanced Superconducting Tokamak.

A MnOx-NbOx-CeO2 catalyst for low temperature selective catalytic reduction (SCR) of NOx with NH3 was prepared by a sol-gel method, and characterized by NH3-NO/NO2 SCR catalytic activity, NO/NH3 oxidation activity, NOx/NH3 TPD, XRD, BET, H2-TPR and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The results indicate that the MnOx-NbOx-CeO2 catalyst shows excellent low temperature NH3-SCR activity in the temperature range of 150-300°C. Water vapor inhibits the low temperature activity of the catalyst in standard SCR due to the inhibition of NOx adsorption. As the NO2 content increases in the feed, water vapor does not affect the activity in NO2 SCR. Meanwhile, water vapor significantly enhances the N2 selectivity of the fresh and the aged catalysts due to its inhibition of the decomposition of NH4NO3 into N2O.

Effect of water vapor on NH3-NO/NO2 SCR performance of fresh and aged MnOx-NbOx-CeO2 catalysts.

A flat-field extreme ultraviolet (EUV) spectrometer working in the 20-500 Å wavelength range with fast time response has been newly developed to measure line emissions from highly ionized tungsten in the Experimental Advanced Superconducting Tokamak (EAST) with a tungsten divertor, while the monitoring of light and medium impurities is also an aim in the present development. A flat-field focal plane for spectral image detection is made by a laminar-type varied-line-spacing concave holographic grating with an angle of incidence of 87°. A back-illuminated charge-coupled device (CCD) with a total size of 26.6 × 6.6 mm(2) and pixel numbers of 1024 × 255 (26 × 26 μm(2)/pixel) is used for recording the focal image of spectral lines. An excellent spectral resolution of Δλ0 = 3-4 pixels, where Δλ0 is defined as full width at the foot position of a spectral line, is obtained at the 80-400 Å wavelength range after careful adjustment of the grating and CCD positions. The high signal readout rate of the CCD can improve the temporal resolution of time-resolved spectra when the CCD is operated in the full vertical binning mode. It is usually operated at 5 ms per frame. If the vertical size of the CCD is reduced with a narrow slit, the time response becomes faster. The high-time response in the spectral measurement therefore makes possible a variety of spectroscopic studies, e.g., impurity behavior in long pulse discharges with edge-localized mode bursts. An absolute intensity calibration of the EUV spectrometer is also carried out with a technique using the EUV bremsstrahlung continuum at 20-150 Å for quantitative data analysis. Thus, the high-time resolution tungsten spectra have been successfully observed with good spectral resolution using the present EUV spectrometer system. Typical tungsten spectra in the EUV wavelength range observed from EAST discharges are presented with absolute intensity and spectral identification.

A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak.

Traditional Chinese herbal medicines (TCHMs) are promising approach for the treatment of various diseases which have attracted increasing attention all over the world. Chemometrics in quality control of TCHMs are great useful tools that harnessing mathematics, statistics and other methods to acquire information maximally from the data obtained from various analytical approaches. This feature article focuses on the recent studies which evaluating the pharmacological efficacy and quality of TCHMs by determining, identifying and discriminating the bioactive or marker components in different samples with the help of chemometric techniques. In this work, the application of chemometric techniques in the classification of TCHMs based on their efficacy and usage was introduced. The recent advances of chemometrics applied in the chemical analysis of TCHMs were reviewed in detail.

Current application of chemometrics in traditional Chinese herbal medicine research.

Modern drug delivery systems rely on either antibody-based single-surface recognition or on surface-hydrophobicity-based approaches. For a tumor showing various surface mutations, both approaches fail. This publication hereby presents Janus capsules based on polyelectrolyte multilayer microcapsules exhibiting human leucocyte (THP-1 cell line) cell membranes for discriminating HUVEC cells from three different cancer cell lines. Despite destroying the cellular integrity of leucocyte cells, the modified Janus capsules are able to adhere to cancer cells. Leucocyte cell-membrane-coated Janus capsules are phagocytosed with the cellular membrane part pointing to the cells.

How Leucocyte Cell Membrane Modified Janus Microcapsules are Phagocytosed by Cancer Cells.

A large-scale high-efficient enzyme reactor based on polymerized high internal phase emulsion monolith (polyHIPE) was prepared. First, a porous cross-linked polyHIPE monolith was prepared by in-situ thermal polymerization of a high internal phase emulsion containing styrene, divinylbenzene and polyglutaraldehyde. The enzyme of TPCK-Trypsin was then immobilized on the monolithic polyHIPE. The performance of the resultant enzyme reactor was assessed according to the conversion ability of Nα-benzoyl-l-arginine ethyl ester to Nα-benzoyl-l-arginine, and the protein digestibility of bovine serum albumin (BSA) and cytochrome (Cyt-C). The results showed that the prepared enzyme reactor exhibited high enzyme immobilization efficiency and fast and easy-control protein digestibility. BSA and Cyt-C could be digested in 10 min with sequence coverage of 59% and 78%, respectively. The peptides and residual protein could be easily rinsed out from reactor and the reactor could be regenerated easily with 4 M HCl without any structure destruction. Properties of multiple interconnected chambers with good permeability, fast digestion facility and easily reproducibility indicated that the polyHIPE enzyme reactor was a good selector potentially applied in proteomics and catalysis areas.

An easily regenerable enzyme reactor prepared from polymerized high internal phase emulsions.

Polyelectrolyte multilayer (PEM) capsules are promising candidates for many kinds of cancer detection and treatment but are usually intended to deliver cargo to specific sites or to destroy cancer cells based on photothermal effects from the outside. In this publication we prove that it is possible to kill cancer cells from the inside based on phagocytosed PEM capsules. In addition we show how to open the cells and bring the PEM capsules to the surface of cancer cells based on photothermal effects and rapid evaporation of water. Diffusion-based temperature determinations of the photothermal effect up to the evaporation temperature of water are presented.

Leucocyte Membrane-Coated Janus Microcapsules for Enhanced Photothermal Cancer Treatment.

Glycyrrhetic acid (GA), the main hydrolysate of glycyrrhizic acid extracted from the roots of the Chinese herb Glycyrrhiza glabra, was reported to be accumulated in hepatocytes due to the extensive distribution of GA receptors in liver. A series of hepatocyte-specific derivatives on the basis of anetholtrithione and glycyrrhizic were designed and synthesized. The potential beneficial effect was evaluated in carbon tetrachloride (CCl4)-induced liver injury model. In addition, the hepatoprotective activity of these derivatives was assessed by measuring levels of serum marker enzymes, including serum glutamate oxaloacetate transaminase (GOT), serum glutamate pyruvate transaminase (GPT), alkaline phosphatase (AKP), lactate dehydrogenase (LDH) and the ratio of GSH to GSSG. Gratifyingly, compounds 5a-c (100mg/kg, p.o.) markedly prevented CCl4-induced elevation of levels of serum GPT, GOT. A comparative histopathological study of liver exhibited almost a normal liver lobular architecture and cell structure of the livers, as compared to CCl4-treated group. These findings were confirmed with the histopathological observations, where hepatocyte-specific glycyrrhetic acid derivatives 5a-c were capable of reversing the toxic effects of CCl4 on hepatocytes.

Protective effects of hepatocyte-specific glycyrrhetic derivatives against carbon tetrachloride-induced liver damage in mice.

It is well known that liver cancer is a highly aggressive malignancy with poor prognosis. Andrographolide (AD), a major bioactive component of Andrographis paniculata (Burm. F.), is a potential anti-cancer pharmacophore and the synthesis of AD derivatives with better cytotoxicity to cancer cells has attracted considerable attentions. In the present study, we evaluated the in vivo inhibitory effects of ADN-9, a 15-benzylidene substituted derivative of AD, on the growth and metastasis of murine hepatoma H22 using an orthotopic xenograft model and a subcutaneous xenograft model, and we further studied the anti-angiogenic action and the related mechanisms of ADN-9 in vivo and in vitro. Importantly, ADN-9 remarkably suppressed the growth and metastasis of both orthotopic and subcutaneous xenograft tumors, and the serum AFP level in orthotopic hepatoma-bearing mice treated with 100mg/kg ADN-9 (ig.) was decreased to the normal level. We also found that ADN-9 showed stronger abilities than AD in shrinking tumors, suppressing the invasion and metastasis of H22 cells, decreasing the MVD and promoting tumor cell apoptosis in subcutaneous xenograft of mice. Additionally, ADN-9 exhibited stronger inhibitory activity than AD against the migration and VEGF-induced capillary-like tube formation in HUVECs, which was further proved to be associated with attenuating VEGF/VEGFR2/AKT signaling pathway. The present research provides the first evidence that a 15-substituted AD derivative is more promising than the parent compound in therapeutic treatment of liver cancer.

Zhenwei Wu

Davidson School of Chemical Engineering

Purdue University

Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation

Zhenwei Wu

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Davidson School of Chemical Engineering

Purdue University

Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation

Davidson School of Chemical Engineering