Imaging of P-glycoprotein of H69/VP small-cell lung cancer lines by scanning near-field optical microscopy and confocal laser microspectrofluorometer

Chemoresistance remains the major obstacle to successful therapy of the lung cancer. The multi-drug resistance (MDR) is generally associated with altered expression of drug transporter proteins, such as P-glycoprotein (P-gp). So the distribution of P-gp on the membrane is of great importance to further study the interaction between drug and P-gp. In the present work, the P-gp of the H69/VP small-lung cancer cells was detected using monoclonal antibody UIC2. A secondary goat-anti mouse antibody coupled with biotin was used. The fluorescence emission was detected from a streptavidin-Texas Red. Results were investigated by a homemade scanning near-field optical microscope (SNOM) coupled to a confocal laser microspectrofluorometer (CLMF). Topographical images and localized spectra were obtained at the level of one cell membrane. It was found that the distribution of P-gp is not homogeneous and this observation is basically in accord with the fluorescent images obtained by classical microscopy. The distribution of P-gp would be localized in a higher region on a cell surface. This methodology would also enhance our understanding of MDR under physiological conditions.     

Sub-micrometer particulate air pollution and cardiovascular mortality in Beijing, China

Background

While the link between particulate matter and cardiovascular mortality is well established, it is not fully investigated and understood which properties of the aerosol might be responsible for the health effects, especially in polluted mega-city areas.

Objectives

Our goal was to explore the association between daily cardiovascular mortality and different particle metrics in the sub-micrometer range in Beijing, China.

Methods

We obtained daily counts of cause-specific cardiovascular deaths in the Beijing urban area for the period March 2004 to August 2005. Concurrently, continuous measurements of particle number size distributions were performed. Particle number concentrations (NC) between 0.003 μm and 0.8 μm were converted to particle mass and surface area concentrations assuming spherical particles. Semi-parametric Poisson regression models adjusting for trend, seasonality, day of the week, and meteorology were used to estimate immediate, delayed and cumulative particle effects. Additionally, effect modification by air mass origin was investigated.

Results

We observed associations between daily cardiovascular mortality and particle NC for a 2-days delay. Moreover, nearly all particle metrics showed 2-days delayed associations with ischemic heart disease mortality. The strongest association was found for particle NC in the size range 0.03-0.1 μm (7.1% increase in daily mortality with a 95%-confidence interval of 2.9%-11.5%, per an increase of 6250 particles/cm³). Results for surface and mass concentrations with a lag of two days indicated effect modification by air mass origin, whereas effects of particle NC were not modified.

Conclusions

Results show an elevated risk of cardiovascular mortality in Beijing from short-term exposure to particulate air pollution in the sub-micrometer range. Results also indicate that locally produced smaller particles and regionally transported particles may exhibit different effects in Beijing.     

Hierarchically structured transparent hybrid membranes by in situ growth of mesostructured organosilica in host polymer

The elaborate performances characterizing natural materials result from functional hierarchical constructions at scales ranging from nanometres to millimetres, each construction allowing the material to fit the physical or chemical demands occurring at these different levels. Hierarchically structured materials start to demonstrate a high input in numerous promising applied domains such as sensors, catalysis, optics, fuel cells, smart biologic and cosmetic vectors. In particular, hierarchical hybrid materials permit the accommodation of a maximum of elementary functions in a small volume, thereby optimizing complementary possibilities and properties between inorganic and organic components. The reported strategies combine sol-gel chemistry, self-assembly routes using templates that tune the material's architecture and texture with the use of larger inorganic, organic or biological templates such as latex, organogelator-derived fibres, nanolithographic techniques or controlled phase separation. We propose an approach to forming transparent hierarchical hybrid functionalized membranes using in situ generation of mesostructured hybrid phases inside a non-porogenic hydrophobic polymeric host matrix. We demonstrate that the control of the multiple affinities existing between organic and inorganic components allows us to design the length-scale partitioning of hybrid nanomaterials with tuned functionalities and desirable size organization from ?ngstr?m to centimetre. After functionalization of the mesoporous hybrid silica component, the resulting membranes have good ionic conductivity offering interesting perspectives for the design of solid electrolytes, fuel cells and other ion-transport microdevices.     

Real Estate Property Maintenance Optimization Based on Multiobjective Multidimensional Knapsack Problem

The real estate property maintenance problem (REPMP) deals with the problem of the maintenance of real estate property buildings’ components using a limited budget in a limited period to achieve multiple and often conflicting objectives. Maintenance of the components requires a multiannual maintenance action plan optimized simultaneously on different criteria relative to buildings’ maintenance objectives (the quality of service, client satisfaction, regulatory compliance, etc.) while respecting a predetermined budget. This article presents an innovative modeling of REPMP into a multiobjective multidimensional knapsack problem and its optimization using a generalization of the discrete multiobjective particle swarm optimization algorithm and the Pareto optimality. An application of this methodology using data from a real estate property of 22 buildings of a major French company is presented and discussed.     

Half-ball lens couples a beveled fiber probe for depth-resolved spectroscopy: Monte Carlo simulations

In this study, we propose a beveled fiber-optic probe coupled with a half-ball lens for improving the depth-resolved fluorescence measurements of epithelial tissue. The Monte Carlo (MC) simulation results show that for a given excitation-collection fiber separation, the probe design with a bevel-angled collection fiber is more sensitive to detect fluorescence photons emitted from the shallow layer of tissue, whereas the flat-tip collection fiber is in favor of probing fluorescence photons originating from deeper tissue areas. This compact half-ball lens-beveled fiber probe design has the potential to facilitate the depth-resolved fluorescence detection of epithelial tissue.     

Alexithymia and affect intensity of art students.

Previous studies have examined the personality traits of artists. Research indicates significant differences between artists, scientists, and individuals from the general population (Feist, 1998; Chamorro-Premuzic, Furnham, & Reimers, 2007). However, studies examining emotion-related traits of artists are relatively rare. Affective styles and traits may distinguish artists from other groups. The present study focuses on two objectives. The first is to examine the degree to which art students present a specific emotional profile including alexithymia and affect intensity, compared with nonart students. The second objective is to examine the degree to which these characteristics predict level of creativity. Creative performance was evaluated based on productions during an art school workshop. Results indicate that art students present a higher level of alexithymia compared with available norms. However, they show also a higher fantasy life, which appears to be an important trait of art students. Finally, results indicate that art students present a higher level of negative intensity than the general population. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Crystallization of fluorescent quantum dots within a three-dimensional bio-organic template of actin filaments and lipid membranes

Biological molecules and molecular self-assemblies are promising templates to organize well-defined inorganic nanostructures. We demonstrate the ability of a self-assembled three-dimensional crystal template of helical actin protein filaments and lipids bilayers to generate a hierarchical self-assembly of quantum dots. Functionnalized tricystein peptidic quantum dots (QDs) are incorporated during the dynamical self-assembly of this actin/lipid template resulting in the formation of crystalline fibers. The crystal parameters, 26.5×18.9×35.5 nm3, are imposed by the membrane thickness, the diameter, and the pitch of the actin self-assembly. This process ensures the high quality of the crystal and results in unexpected fluorescence properties. This method of preparation offers opportunities to generate crystals with new symmetries and a large range of distance parameters.     

In planta Mechanism of Action of Leptospermone: Impact of Its Physico-Chemical Properties on Uptake, Translocation, and Metabolism

Leptospermone is a natural β-triketone that specifically inhibits the enzyme p-hydrophyphenylpyruvate dioxygenase, the same molecular target site as that of the commercial herbicide mesotrione. The β-triketone-rich essential oil of Leptospermum scoparium has both preemergence and postemergence herbicidal activity, resulting in bleaching of treated plants and dramatic growth reduction. Radiolabeled leptospermone was synthesized to investigate the in planta mechanism of action of this natural herbicide. Approximately 50 % of the absorbed leptospermone was translocated to the foliage suggesting rapid acropetal movement of the molecule. On the other hand, very little leptospermone was translocated away from the point of application on the foliage, indicating poor phloem mobility. These observations are consistent with the physico-chemical properties of leptospermone, such as its experimentally measured logP and pK _a values, and molecular mass, number of hydrogen donors and acceptors, and number of rotatable bonds. Consequently, leptospermone is taken up readily by roots and translocated to reach its molecular target site. This provides additional evidence that the anecdotal observation of allelopathic suppression of plant growth under β-triketone-producing species may be due to the release of these phytotoxins in soils.