Angiogenic protein expression in advanced epithelial ovarian cancer

We set out to determine whether advanced epithelial ovarian cancer (EOC) is associated with elevated serum and ascitic concentrations of the angiogenic factors angiogenin (ANG), basic fibroblastic growth factor (bFGF), and vascular endothelial growth factor (VEGF), and whether the expression of angiogenic factors was associated with tumor vascularity. Serum and ascitic samples were collected from previously untreated patients with FIGO stage III and IV EOC and stored at -70 degreesC. Levels of the three factors were determined by enzyme-linked immunoassay. Histological sections from paraffin blocks of ovarian cancers were stained immunochemically for factor VIII, CD34, and VEGF. Thirty-nine patients were studied, although not all had paired serum and ascitic samples. For each angiogenic factor, the following findings were noted: (a) there was a wide range in serum and ascitic fluid concentrations; (b) the mean serum concentration was higher (P < 0.05) than the mean concentration in normal serum; and (c) the mean serum concentration was lower (P < 0. 05) than the mean ascitic concentration. Overall, the most consistent pattern of elevated serum and ascitic concentrations was with bFGF. With serum samples, 38.9% of patients had a normal VEGF concentration, as did 15.3% for ANG and 7.7% for bFGF. In ascites, the VEGF concentration was in the range for normal serum in 24.5% of samples, compared to 39.4% for ANG and 2.8% for bFGF. In paired samples, both VEGF and bFGF showed higher ascitic concentrations in 100 and 88.3% of samples, compared to 53.3% for ANG. There was no correlation between the serum and/or ascitic concentration of one factor and that of another, suggesting that these factors are independently regulated. Staining with anti-CD34 was more sensitive and reliable than with anti-factor VIII. VEGF staining was most prominent in poorly differentiated tumors and was observed only on tumor cells. There was no correlation between the serum or ascitic concentrations of angiogenic factors and tumor vascularity. Advanced EOC is associated with raised serum and ascitic bFGF concentrations and with markedly elevated ascitic VEGF in most cases. Serum VEGF and serum and ascitic ANG are less often elevated. There was no correlation between the angiogenic profile in serum and ascites and tumor vascularity.     

High-Throughput Magnetic Actuation Platform for Evaluating the Effect of Mechanical Force on 3D Tumor Microenvironment

Accurately replicating and analyzing cellular responses to mechanical cues is vital for exploring metastatic disease progression. However, many of the existing in vitro platforms for applying mechanical stimulation seed cells on synthetic substrates. To better recapitulate physiological conditions, a novel actuating platform is developed with the ability to apply tensile strain on cells at various amplitudes and frequencies in a high-throughput multi-well culture plate using a physiologically relevant substrate. Suspending fibrillar fibronectin across the body of the magnetic actuator provides a matrix representative of early metastasis for 3D cell culture that is not reliant on a synthetic substrate. This platform enables the culturing and analysis of various cell types in an environment that mimics the dynamic stretching of lung tissue during normal respiration. Metabolic activity, YAP activation, and morphology of breast cancer cells are analyzed within one week of cyclic stretching or static culture. Further, matrix degradation is significantly reduced in breast cancer cell lines with metastatic potential after actuation. These new findings demonstrate a clear suppressive cellular response due to cyclic stretching that has implications for a mechanical role in the dormancy and reactivation of disseminated breast cancer cells to macrometastases.     

Performance and thermodynamic properties of Na-Sn and Na-Pb molten alloy electrodes for alkali metal thermoelectric converter (AMTEC)

An alkali metal thermoelectric converter (AMTEC) testing cell was set up, and run with molten sodium-tin (Na-Sn) and sodium-lead (Na-Pb) alloy cathodes. The Na activity, the partial molar enthalpy and partial molar entropy of sodium in molten Na-Sn and Na-Pb alloys have been determined, using a Na concentration cell: Na(1) I beta-alumina Na-Me(1), where Me= Sn or Pb. The thermodynamic results of these investigations agree with those of other authors. The electric performance of these Na-Me alloy electrodes of different Na concentration and temperatures is described, measuring current-voltage characteristics and a.c. impedance in the AMTEC test cell. The power density of the AMTEC cell with molten alloy cathodes decreases with increasing Na concentration, with the Na concentrations in molten alloys varying from 0.5 to 15 mol%. Maximum power densities of 0.21 to 0.15 W cm^–2 at 700°C for Na-Sn molten electrodes, and 0.30 to 0.15 W cm^–2 for Na-Pb molten electrodes have been obtained. The a.c. impedance data demonstrated that the molten alloy electrodes have a smaller cell resistance, 0.3–0.35 S2 cm^–2 at 700°C after 10–20 h. Comparison with the sputtered thin, porous film electrodes, showed that the contact resistance between electrode and surface of beta-alumina plays an important role on enhancing cell power density. At 700°C the power density of an AMTEC cell with the molten Na-Pb alloy electrode can be raised to values of about 0.2 W cm eat current densities of 0.8 A cm^–2, but at cell voltages not exceeding 0.2V. A model for the theoretical efficiency of the AMTEC cell with molten Na metal electrodes is also presented.     

Electrical efficiencies of methane fired, high- and low- temperature fuel cell power plants

The important system difference between power plants based on low temperature and high temperature fuel cells is that gas reforming and shift conversion is thermally decoupled from the cell in low temperature cell power plants whereas the gas process steps are performed at close to the elevated fuel cell temperatures in high temperature fuel cell power plants. This article elucidates the consequences: assuming equal electrical efficiencies for the respective cells (50%) it is shown that thermal decoupling leads to energy and exergy losses and sizably lower electrical system efficiencies because heat for the generation of the process steam necessitates the combustion of methane. Also hydrogen losses in the step for preferential oxidation of carbon monoxide (Selox process) and several heat transfer steps add to the lower efficiency of low temperature systems. Low temperature fuel cell power plants need 15–17% more fuel than high temperature fuel cell power plants for the same amount of electric energy. The theoretical comparison of an adiabatic LT and HT fuel cell process reveals that, with postulated electrical cell efficiencies of 50%, the theoretical electrical efficiency of the LT process is 6–7% points lower than that for the HT-process (35 vs. 41%). For exergy efficiencies also taking into account rejected heats, the numbers read 43 and 58%.     

Health effects engineering of coal and biomass combustion particulates: influence of zinc, sulfur and process changes on potential lung injury from inhaled ash

This paper is concerned with health effects of the ash aerosol formed from the co-combustion of municipal sewage sludge (a CO₂ neutral, ostensibly ‘green’ biomass fuel) with pulverized coal. To study, and mitigate, possible lung injury caused by inhalation of these ash particles, it is useful to employ ‘Health Effects Engineering’, which involves collaboration between combustion researchers and toxicologists. Health Effects Engineering attempts to build connections between mechanisms that form particulates during the combustion process and mechanisms that cause these ill health effects. By employing the methods of Health Effects Engineering, one can determine not only which fuel attributes are likely to contribute to lung injury, but also how tendencies of the ash to cause lung injury can be engineered out of the combustion process.Initial results showed that inhalation of ash from the co-combustion of municipal sewage sludge (MSS) and pulverized coal caused much greater lung damage in mice, as measured by lung permeability increase, than that of coal ash, or MSS ash, alone. MSS contains substantial quantities of zinc but little sulfur, while coal contains sulfur but little zinc. Therefore, systematic experiments were conducted to determine the health effects of combustion generated zinc particles and zinc plus sulfur particles. Zinc without sulfur led to ‘normal’ behavior as far as lung permeability was concerned. Zinc with sulfur added led to the ‘abnormal’ behavior noted also in the coal+MSS experiments. Therefore, the bad actor was identified to be zinc together with sulfur, and that was why the co-combustion of coal and MSS caused greater lung injury than the combustion of either fuel alone. Health effects engineering can also be employed to diminish this health risk caused by burning fuels containing both zinc and sulfur. Injection of a kaolinite sorbent downstream of the flame, but above the Zn dew point, can sequester the Zn, and react it to form a new species which was shown to be relatively benign.     

Electrode coatings for high temperature hydrogen electrolysis

A discussion of fabrication techniques and performance testing of solid oxide components for use in hydrogen steam electrolysis is presented. Novel plasma spray techniques are utilized to deposit the thin ceramic oxide electrode, electrolyte, and interconnect layers on a planar intermetallic bipolar plate. Optimal porosity is achieved within the electrode microstructure through mixed feed techniques that are a combination of dry powder feed and liquid solution injection. The perovskite anode coatings formed from liquid precursor feedstock require post-deposition annealing in an oxygen-rich atmosphere to form the desired perovskite structures. Electrical conductivity measurements were measured for all electrodes and interconnect materials as a function of temperature to 1000 °C. Supported by the U.S. Department of Energy, Office of Nuclear Energy Science and Technology, under the DOE Idaho Operations Contract No. DE-AC07-05ID14517     

LaMnO3 Perovskite Supported Noble Metal Catalysts for the Total Oxidation of Methane

Two series of LaMnO₃ supported noble metal (Pt, Pd, Rh) catalysts prepared by the citrate method and calcined in air at 600 and 800 °C, respectively, were investigated. The catalysts resulting from method A were prepared by simultaneous incorporation of the noble metals during perovskite preparation and those following method B were generated by impregnation of the calcined perovskites with the noble metal compounds. The noble metals form solid solutions with the perovskite lattice. Reduction of the catalysts with hydrogen prior to the catalytic reaction led to a significant enhancement of the catalytic activity. During the catalytic reaction, the noble metal clusters are partially transformed to highly dispersed noble metal oxides or nonstoichiometric noble metal oxide phases, which are the catalytically active phases for the total oxidation of methane. The best results were obtained with the Pd containing catalysts prepared by method B.     

Thymus Extracellular Matrix-Derived Scaffolds Support Graft-Resident Thymopoiesis and Long-Term In Vitro Culture of Adult Thymic Epithelial Cells

The thymus provides the physiological microenvironment critical for the development of T lymphocytes, the cells that orchestrate the adaptive immune system to generate an antigen-specific response. A diverse population of stroma cells provides surface-bound and soluble molecules that orchestrate the intrathymic maturation and selection of developing T cells. Forming an intricate 3D architecture, thymic epithelial cells (TEC) represent the most abundant and important constituent of the thymic stroma. Effective models for in and ex vivo use of adult TEC are still wanting, limiting the engineering of functional thymic organoids and the understanding of the development of a competent immune system. Here a 3D scaffold is developed based on decellularized thymic tissue capable of supporting in vitro and in vivo thymopoiesis by both fetal and adult TEC. For the first time, direct evidences of feasibility for sustained graft-resident T-cell development using adult TEC as input are provided. Moreover, the scaffold supports prolonged in vitro culture of adult TEC, with a retained expression of the master regulator Foxn1. The success of engineering a thymic scaffold that sustains adult TEC function provides unprecedented opportunities to investigate thymus development and physiology and to design and implement novel strategies for thymus replacement therapies.     

Extraction with Water-in-Carbon Dioxide Microemulsions: A Case Study on Steviol Glycosides

This work explores the use of water-in-supercritical carbon dioxide (scCO₂) microemulsions for the extraction of polar metabolites from plants. Stevia rebaudiana Bertoni leaves and polyethylene glycol trimethylnonyl ether (TMN) surfactants were selected for a case study. A CO₂-water-TMN 10 mixture at 35 °C and 30.0 MPa extracted 7 mg target analyte/g dry leaves. The extraction was proven to occur due to a water-surfactant liquid solution rather than a water-in-CO₂ microemulsion. Using a modified extraction setup, the microemulsion was created prior to extraction. TMN 6 was able to dissolve enough water in CO₂ to extract steviol glycosides, in detectable but very small amounts.