Absolute Quantification of Selected Proteins in the Human Osteoarthritic Secretome

Osteoarthritis (OA) is characterized by a loss of extracellular matrix which is driven by catabolic cytokines. Proteomic analysis of the OA cartilage secretome enables the global study of secreted proteins. These are an important class of molecules with roles in numerous pathological mechanisms. Although cartilage studies have identified profiles of secreted proteins, quantitative proteomics techniques have been implemented that would enable further biological questions to be addressed. To overcome this limitation, we used the secretome from human OA cartilage explants stimulated with IL-1β and compared proteins released into the media using a label-free LC-MS/MS-based strategy. We employed QconCAT technology to quantify specific proteins using selected reaction monitoring. A total of 252 proteins were identified, nine were differentially expressed by IL-1 β stimulation. Selected protein candidates were quantified in absolute amounts using QconCAT. These findings confirmed a significant reduction in TIMP-1 in the secretome following IL-1β stimulation. Label-free and QconCAT analysis produced equivocal results indicating no effect of cytokine stimulation on aggrecan, cartilage oligomeric matrix protein, fibromodulin, matrix metalloproteinases 1 and 3 or plasminogen release. This study enabled comparative protein profiling and absolute quantification of proteins involved in molecular pathways pertinent to understanding the pathogenesis of OA.     

Uranium and technetium bio-immobilization in intermediate-scale physical models of an in situ bio-barrier

We investigated the long-term effects of ethanol addition on U and Tc mobility in groundwater flowing through intermediate-scale columns packed with uncontaminated sediments. The columns were operated above-ground at a contaminated field site to serve as physical models of an in situ bio-barrierfor U and Tc removal from groundwater. Groundwater containing 4 microM U and 520 pM Tc was pumped through the columns for 20 months. One column received additions of ethanol to stimulate activity of indigenous microorganisms; a second column received no ethanol and served as a control. U(VI) and Tc(VII) removal was sustained for 20 months (approximately 189 pore volumes) in the stimulated column under sulfate- and Fe(III)-reducing conditions. Less apparent microbial activity and only minor removal of U(VI) and Tc(VII) were observed in the control. Sequential sediment extractions and XANES spectra confirmed that U(IV) was present in the stimulated column, although U(IV) was also detected in the control; extremely low concentrations precluded detection of Tc(IV) in any sample. These results provide additional evidence that bio-immobilization may be effective for removing U and Tc from groundwater. However, long-term effectiveness of bio-immobilization may be limited by hydraulic conductivity reductions or depletion of bioavailable Fe(III).     

An integrated system for publishing environmental observations data

Over the next decade, it is likely that science and engineering research will produce more scientific data than has been created over the whole of human history. The successful use of these data to achieve new scientific breakthroughs will depend on the ability to access, integrate, and analyze these large datasets. Robust data organization and publication methods are needed within the research community to enable data discovery and scientific analysis by researchers other than those that collected the data. We present a new method for publishing research datasets consisting of point observations that employs a standard observations data model populated using controlled vocabularies for environmental and water resources data along with web services for transmitting data to consumers. We describe how these components have reduced the syntactic and semantic heterogeneity in the data assembled within a national network of environmental observatory test beds and how this data publication system has been used to create a federated network of consistent research data out of a set of geographically decentralized and autonomous test bed databases.     

Complex metal oxide catalysts for selective oxidation of propane and derivatives: II. The relationship among catalyst preparation, structure and catalytic properties

The effects of the preparation methods on the structure and catalytic performance of the MVTeNb (M=Mo or W) complex metal oxides (CMO) in selective oxidation of propane to acrylic acid (AA) were investigated. Preparation methods can play as significant roles as the chemical composition in determining the structures and catalytic properties of a CMO catalyst. Undesirable preparation methods or conditions can lead to the formation of ineffective crystal phases in the resulting catalysts, leading to poor catalytic activity or selectivity. An effective MoVTeNb oxide catalyst for propane selective oxidation to acrylic acid could be obtained with a combination of a proper metal ratio and proper preparation procedures. Certain drying methods, such as freeze dry and heat evaporation, are undesirable because phase segregation tends to occur during such processes, which negatively affect the catalytic performance. The preferred drying method is the rotavap method, which favors the formation of an effective crystal phase and suppresses the formation of impurity phases. The preferred calcination atmosphere is an inert atmosphere while a calcination atmosphere containing oxygen leads to the formation of significant amounts of MO₃ in MVTeNb oxides (M=Mo or W), which is known to be inactive in propane oxidation. It is proposed that an effective MoVTeNb oxide catalyst for propane selective oxidation to acrylic acid should contain at least two major crystal Phases A and B. Based on studies of oxides of pure Phase A and those exclusively enriched with Phase B, X-ray diffraction (XRD) characteristics of the two major crystal phases (A and B) have been identified and their catalytic functions studied. It is proposed that Phase A is active in propane activation but relatively unselective for the acrylic acid formation, while Phase B is reasonably active for propane activation and fairly selective for acrylic acid formation. It has been shown that using MoVTeNb oxide catalyst with a proper ratio of Phases A and B and synergy between them, very high propane conversion (73%) and acrylic acid selectivity (58%) can be achieved at the same time.