Dramatic increases in the price of crude oil, and consequently, transportation fuels, coupled with increased environmental concerns have resulted in rapid growth in biodiesel production, both in the United States and worldwide. As biodiesel production increases, so does production of the primary coproduct, glycerol. Since the existing glycerol supply and demand market was tight, recent increases in glycerol production from biodiesel refining has created a glut in the glycerol market. As a result, the price of glycerol has fallen significantly and biodiesel refiners are faced with limited options for managing the glycerol by‐product, which in the biodiesel industry, has essentially become a waste stream. This article is a review of promising options for both the catalytic and biological conversion of glycerol into various value‐added products, many of which are bio‐based alternatives to petroleum‐derived chemicals. © 2007 American Institute of Chemical Engineers Environ Prog, 26: 338–348, 2007

This review shows that adolescent depression increases the risk for subsequent depression later in life. Articles consistently found that adolescent depression increases the risk for anxiety disorders in adulthood, but evidence was mixed on whether or not a significant association existed between adolescent depression and suicidality in adulthood. Early intervention in adolescent depression may reduce long-term burden of disease.

Hyperthermia can be produced by near-infrared laser irradiation of gold nanoparticles present in tumors and thus induce tumor cell killing via a bystander effect. To be clinically relevant, however, several problems still need to be resolved. In particular, selective delivery and physical targeting of gold nanoparticles to tumor cells are necessary to improve therapeutic selectivity. Considerable progress has been made with respect to retargeting adenoviral vectors for cancer gene therapy. We therefore hypothesized that covalent coupling of gold nanoparticles to retargeted adenoviral vectors would allow selective delivery of the nanoparticles to tumor cells, thus feasibilizing hyperthermia and gene therapy as a combinatorial therapeutic approach. For this, sulfo-N-hydroxysuccinimide labeled gold nanoparticles were reacted to adenoviral vectors encoding a luciferase reporter gene driven by the cytomegalovirus promoter (AdCMVLuc). We herein demonstrate that covalent coupling could be achieved, while retaining virus infectivity and ability to retarget tumor-associated antigens. These results indicate the possibility of using adenoviral vectors as carriers for gold nanoparticles.

Tailoring the surface of nanoparticles is essential for biological applications of magnetic nanoparticles. FePt nanoparticles are interesting candidates owing to their high magnetic moment. Established procedures to make FePt nanoparticles use oleic acid and oleylamine as the surfactants, which make them dispersed in nonpolar solvents such as hexane. As a model study to demonstrate the modification of the surface chemistry, stable aqueous dispersions of FePt nanoparticles were synthesized after ligand exchange with mercaptoalkanoic acids. This report focuses on understanding the surface chemistry of FePt upon ligand exchange with mercapto compounds by conducting X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) studies. It was found that the mercapto end displaces oleylamine on the Pt atoms and the carboxylic acid end displaces the oleic acid on the Fe atoms, thus exposing carboxylate and thiolate groups on the surface that provide the necessary electrostatic repulsion to form stable aqueous dispersions of FePt nanoparticles.

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The rapidly expanding market for biodiesel is dramatically altering the cost and availability of glycerol, as typical biodiesel production processes generate about 10 wt % glycerol. Biodiesel producers have little financial incentive to purify the crude glycerol, and because it contains methanol, crude glycerol is considered a hazardous waste. Therefore, it is critical that new and innovative processes for managing and utilizing the glycerol co‐product be developed. In the longer term, as supplies continue to increase, glycerol will become a versatile building block chemical for the production of high value compounds within an integrated biorefinery. This research investigated the value‐added conversion of crude glycerol generated during biodiesel production using anaerobic fermentation. Pure cultures of Clostridium pasteurianum have been shown to produce significant amounts of butanol and 1,3‐propanediol when utilizing purified glycerol as the sole substrate. Butanol is of particular interest as a renewable biofuel, as it has a higher heating value, higher octane number, lower vapor pressure, and higher miscibility than ethanol, making butanol preferable to ethanol for blending with petroleum fuels. Preliminary experiments compared growth and product formation of C. pasteurianum (ATCC®6013™) utilizing both purified and biodiesel‐derived crude glycerol as the sole carbon source in batch culture. Cultures utilizing crude glycerol demonstrated significant growth and production of butanol, 1,3‐PDO, and ethanol at concentrations up to 25 g/L crude glycerol. This work is significant in that it is the first report of butanol production from crude glycerol using this organism. The maximum yield of butanol produced from pure glycerol was 0.36 g/g, while the maximum butanol yield produced from crude glycerol was 0.30 g/g. These yields are substantially higher than the 0.15–0.20 g/g butanol yield typically achieved during the fermentation of glucose using C. acetobutylicum. These results indicate that biodiesel‐derived crude glycerol is a promising, low‐cost, renewable feedstock for butanol production. © 2009 American Institute of Chemical Engineers Environ Prog, 2009

In this paper, we show that the surface tension of charge-stabilized titania suspensions strongly depends on the particle concentration. The surface tension first decreases significantly with an increase in the weight percent and then increases with a further increase in the weight percent. Thermodynamic arguments are used to explain the initial decrease in the surface tension for lower particle concentrations. For higher concentrations, it is hypothesized that the capillary forces acting between the immersed particles at the interface cause the increase in the surface tension.

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