Air concentrations of PCBs and PAHs were measured in the urban/industrial complex of Chicago, IL, over southern Lake Michigan, and in a non-urban area as part of the AEOLOS (Atmospheric Exchange Over Lakes and Oceans) Project. Air samples were collected simultaneously in intensive experiments during May and July 1994 and January 1995 in order to determine the influence of contaminated air masses from the Chicago urban/industrial complex on the southern Lake Michigan atmosphere. Gas phase ∑PAH concentrations over the lake ∼10-20 km offshore ranged from 0.8 to 70 ng/m 3 while urban air concentrations were 27-430 ng/m 3 . Photooxidation of gas phase PAHs during the day resulted in daytime over-lake concentrations that were ∼75% less than corresponding nighttime concentrations. Gas phase ∑PCB concentrations ranged from 0.14 to 1.1 ng/m 3 over the lake and from 0.27 to 14 ng/m 3 in the urban area. ∑PCB concentrations varied seasonally as a result of higher volatilization during the summer. The highest concentrations occurred when the air flow was from the urban/industrial area encompassing Evanston, IL, to Gary, IN, toward the lake, and concentrations were near regional background when the wind was from any other direction. The urban air emissions increased the average coastal atmospheric concentrations above the continental background signal by factors of 12 and 4 for ∑PAHs and ∑PCBs, respectively. Because of photooxidation of gas phase PAHs during the day, the average daytime concentration was increased by only a factor of 5 while the average nighttime concentration was increased by a factor of 18.

Simultaneous air samples were taken in Chicago and over southern Lake Michigan as part of the AEOLOS Project (Atmospheric Exchange Over Lakes and Oceans). Gas and particle phase concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and total suspended particles (TSP) were measured over 12 h periods during July, 1994, and January, 1995. Partitioning of PCBs and PAHs between gas and particle phases was well correlated with the subcooled liquid vapor pressure (p°L) for individual samples, but the relationship differed among samples. For all but a few of the samples the slopes of the log K p vs log p°L lines were statistically greater than -1. Other investigators who have found similar results have concluded that the PCBs/PAHs were not at equilibrium; however, other factors indicate that the PCBs and PAHs in the Chicago/Lake Michigan atmosphere are at equilibrium. Slopes of the regressions of log K p vs log p°L from samples of continental background origin, and therefore assumed to have had sufficient atmospheric residence times to reach equilibrium, are among the shallowest measured (-0.70 to -0.53 and -0.16 to -0.56 for PAHs and PCBs, respectively). One pair of samples where the air mass is believed to have been sampled twice, once in the urban area and again ∼3.4 h downwind, shows no difference in partitioning. PCBs and PAHs measured in Chicago and over Lake Michigan were apparently at equilibrium between the gas and particle phases. A slope of -1 in the regression of log K p vs log p°L is not necessary to describe equilibrium partitioning. Differences in particulate matter may be responsible for the shallow slopes observed.

Urban-industrial areas exhibit atmospheric concentrations of organic contaminants that are often > 5-10× regional background. Increased emissions of PCBs into the urbanindustrial atmosphere leads to enhanced depositional fluxes to proximate waters. In this study, the increased airwater exchange inputs of PCB congeners into southern Lake Michigan driven by elevated atmospheric concentrations emanating from the Chicago, IL/Gary, IN air plume was studied. Intensive experiments were conducted in May and July 1994 and January 1995. The gaseous ΣPCB concentrations at the overlake site 15-km from Chicago ranged from 132 to 1120 pg/m 3 with higher concentrations occurring in warm periods and when winds were from southerly and westerly quadrants. Dissolved phase ΣPCB concentrations ranged from 48 to 302 pg/L with concentrations in winter ∼2.5× higher than summer concentrations. Instantaneous net air-water exchange fluxes ranged from -32 (absorption) to + 59 ng/m 2 -d with absorptive flux highest in summer when winds were from the urban area and gas-phase concentrations were highest. Air and surface water temperatures and wind direction were the dominant factors influencing the magnitude and direction of air-water exchange fluxes. The modeled net air-water exchange flux of ΣPCB in the southern quarter of Lake Michigan was -18 ug/m 2 -yr (net absorption) in 1994, corresponding to 140 kg/yr net input.

Background/Aims: Plasmacytoma variant translocation 1 (PVT1) exerts an oncogenic role in many tumors, including lung cancer. However, the roles of PVT1 in regulating radiosensitivity of NSCLC and its underlying mechanism are still unclear. Methods: Expression levels of PVT1 and miR-195 in NSCLC tissues and cells were examined by qRT-PCR. Effects of PVT1 and miR-195 on cell proliferation, apoptosis and colony formation abilities were assessed by MTT assay, flow cytometry and colony formation assay. Luciferase reporter assay was performed to confirm the relationship between PVT1 and miR-195. Tumor xenograft experiments were conducted to observe the effect of PVT1 on radiosensitivity of NSCLC in vivo. Results: PVT1 was negatively correlated with miR-195 expression in NSCLC tissues and associated with poor prognosis of NSCLC patients. Expression of PVT1 and miR-195 varied inversely after irradiation in NSCLC cells. PVT1 knockdown or miR-195 overexpression enhanced radiosensitivity of NSCLC in vitro by inhibiting proliferation and inducing apoptosis. PVT1 directly interacted with miR-195 and regulated its expression. Moreover, PVT1 knockdown improved radiosensitivity of NSCLC cells in vitro and in vivo by sponging miR-195. Conclusion: Knockdown of PVT1 enhances radiosensitivity of NSCLC by sponging miR-195, providing a novel therapeutic target to improve radiotherapy efficiency in NSCLC.

Novel autoregulatory metabolites, arthrosporols A−C (1−3), involved in regulating the morphological switch in fungi, were purified and characterized from the carnivorous fungus Arthrobotrys oligospora. These compounds possess a novel hybrid carbon skeleton consisting of an epoxycyclohexenol combined with a rare monocyclic sesquiterpenol substructure. This is the first report of a monocyclic sesquiterpenol of this type of fungal origin. Compounds 1−3 displayed significant inhibitory activities toward the formation of conidiophores, while compounds 1 and 3 showed the opposite effects on the formation of a two-dimensional network with increasing rates of 40−90% and inhibiting rates of 30−90%, respectively.

Diffusion coefficients of drug compounds are crucial parameters used for modeling transport processes. Interestingly, diffusion of a solute can be generated not only by its own concentration gradient but also by concentration gradients of other solutes. This phenomenon is known as multicomponent diffusion. A multicomponent diffusion study on drug-surfactant-water ternary mixtures is reported here. Specifically, high-precision Rayleigh interferometry was used to determine multicomponent diffusion coefficients for the hydrocortisone-tyloxapol-water system at 25 degrees C. For comparison, diffusion measurements by dynamic light scattering were also performed. In addition, drug solubility was measured as a function of tyloxapol concentration, and drug-surfactant thermodynamic interactions using the two-phase partitioning model were characterized. The diffusion results are in agreement with a proposed coupled multicomponent diffusion model for ternary mixtures relevant to nonionic drug and surfactant molecules. Theoretical examination of diffusion-based drug transport in the presence of concentration gradients of micelles shows that drug fluxes and drug concentration profiles are significantly affected by coupled multicomponent diffusion. This work provides guidance for the development of accurate models of diffusion-based controlled release in multicomponent systems and for the applications of micelle concentration gradients to the modulation of diffusion-based drug transport.

The role of salting-out strength on (1) polymer diffusiophoresis from high to low salt concentration, and (2) salt osmotic diffusion from high to low polymer concentration was investigated. These two cross-diffusion phenomena were experimentally characterized by Rayleigh interferometry at 25 °C. Specifically, we report ternary diffusion coefficients for polyethylene glycol (molecular weight, 20 kg·mol(-1)) in aqueous solutions of several salts (NaCl, KCl, NH4Cl, CaCl2, and Na2SO4) as a function of salt concentration at low polymer concentration (0.5% w/w). We also measured polymer diffusion coefficients by dynamic light scattering in order to discuss the interpretation of these transport coefficients in the presence of cross-diffusion effects. Our cross-diffusion results, primarily those on salt osmotic diffusion, were utilized to extract N(w), the number of water molecules in thermodynamic excess around a macromolecule. This preferential-hydration parameter characterizes the salting-out strength of the employed salt. For chloride salts, changing cation has a small effect on N(w). However, replacing NaCl with Na2SO4 (i.e., changing anion) leads to a 3-fold increase in N(w), in agreement with cation and anion Hofmeister series. Theoretical arguments show that polymer diffusiophoresis is directly proportional to the difference N(w) - n(w), where n(w) is the number of water molecules transported by the migrating macromolecule. Interestingly, the experimental ratio, n(w)/N(w), was found to be approximately the same for all investigated salts. Thus, the magnitude of polymer diffusiophoresis is also proportional to salting-out strength as described by N(w). A basic hydrodynamic model was examined in order to gain physical insight on the role of n(w) in particle diffusiophoresis and explain the observed invariance of n(w)/N(w). Finally, we consider a steady-state diffusion problem to show that concentration gradients of strong salting-out agents such as Na2SO4 can produce large amplifications and depletions of macromolecule concentration. These effects may be exploited in self-assembly and adsorption processes.

Arthrobotrys oligospora is a carnivorous fungus that can use mycelia trapping devices to capture their prey. Three novel oligosporons, named arthrobotrisins A-C (1-3), were isolated from A. oligospora and identified by spectroscopic analysis in combination with X-ray diffraction. This is the first time that the relative configuration of naturally occurring oligosporon metabolites has been fully determined. Compound 3 exhibited specific antibacterial activities.