ToxTracker Reporter Cell Lines as a Tool for Mechanism-Based (geno)Toxicity Screening of Nanoparticles-Metals, Oxides and Quantum Dots.

The increased use of nanoparticles (NPs) requires efficient testing of their potential toxic effects. A promising approach is to use reporter cell lines to quickly assess the activation of cellular stress response pathways. This study aimed to use the ToxTracker reporter cell lines to investigate (geno)toxicity of various metal- or metal oxide NPs and draw general conclusions on NP-induced effects, in combination with our previous findings.

Influence of humic acid and dihydroxy benzoic acid on the agglomeration, adsorption, sedimentation and dissolution of copper, manganese, aluminum and silica nanoparticles - A tentative exposure scenario.

This work focuses on kinetic aspects of stability, mobility, and dissolution of bare Cu, Al and Mn, and SiO2 NPs in synthetic freshwater (FW) with and without the presence of natural organic matter (NOM). This includes elucidation of particle and surface interactions, metal dissolution kinetics, and speciation predictions of released metals in solution. Dihydroxy benzoic acid (DHBA) and humic acid adsorbed rapidly on all metal NPs (<1 min) via multiple surface coordinations, followed in general by rapid agglomeration and concomitant sedimentation for a large fraction of the particles.

Nanoparticles of WC-Co, WC, Co and Cu of relevance for traffic wear particles - Particle stability and reactivity in synthetic surface water and influence of humic matter.

Studded tyres made of tungsten carbide cobalt (WC-Co) are in the Northern countries commonly used during the winter time. Tungsten (W)-containing nano- and micron-sized particles have been detected close to busy roads in several European countries. Other typical traffic wear particles consist of copper (Cu).

Effect of sonication on particle dispersion, administered dose and metal release of non-functionalized, non-inert metal nanoparticles.

Abstract: In this study, we elucidate the effect of different sonication techniques to efficiently prepare particle dispersions from selected non-functionalized NPs (Cu, Al, Mn, ZnO), and corresponding consequences on the particle dose, surface charge and release of metals. Probe sonication was shown to be the preferred method for dispersing non-inert, non-functionalized metal NPs (Cu, Mn, Al). However, rapid sedimentation during sonication resulted in differences between the real and the administered doses in the order of 30-80 % when sonicating in 1 and 2.

Sequential studies of silver released from silver nanoparticles in aqueous media simulating sweat, laundry detergent solutions and surface water.

From an increased use of silver nanoparticles (Ag NPs) as an antibacterial in consumer products follows a need to assess the environmental interaction and fate of their possible dispersion and release of silver. This study aims to elucidate an exposure scenario of the Ag NPs potentially released from, for example, impregnated clothing by assessing the release of silver and changes in particle properties in sequential contact with synthetic sweat, laundry detergent solutions, and freshwater, simulating a possible transport path through different aquatic media. The release of ionic silver is addressed from a water chemical perspective, compared with important particle and surface characteristics.

Effect of laundry surfactants on surface charge and colloidal stability of silver nanoparticles.

The stability of silver nanoparticles (Ag NPs) potentially released from clothing during a laundry cycle and their interactions with laundry-relevant surfactants [anionic (LAS), cationic (DTAC), and nonionic (Berol)] have been investigated. Surface interactions between Ag NPs and surfactants influence their speciation and stability. In the absence of surfactants as well as in the presence of LAS, the negatively charged Ag NPs were stable in solution for more than 1 day.

Intracranial sarcoid granuloma as an extension of severe sinonasal sarcoidosis.

Sarcoidosis is a chronic, multisystem, granulomatous disease of unknown etiology. It manifests with a wide range of symptoms and clinical findings, including some that occur in the head and neck. Sinonasal sarcoidosis, in particular, frequently demonstrates a rather recalcitrant course and a potential for severe complications if left untreated.

Interactions between surfactants and silver nanoparticles of varying charge.

The interaction between silver nanoparticles (Ag NPs) of different surface charge and surfactants relevant to the laundry cycle has been investigated to understand changes in speciation, both in and during transport from the washing machine. Ag NPs were synthesized to exhibit either a positive or a negative surface charge in solution conditions relevant for the laundry cycle (pH 10 and pH 7). These particles were characterized in terms of size and surface charge and compared to commercially laser ablated Ag NPs.

Porosity investigation of compacted bentonite using XRD profile modeling.

Many countries intend to use compacted bentonite as a barrier in their deep geological repositories for nuclear waste. In order to describe and predict hydraulic conductivity or radionuclide transport through the bentonite barrier, fundamental understanding of the microstructure of compacted bentonite is needed. This study examined the interlayer swelling and overall microstructure of Wyoming Bentonite MX-80 and the corresponding homo-ionic Na(+) and Ca(2+) forms, using XRD with samples saturated under confined swelling conditions and free swelling conditions.

Role of the pediatric otolaryngologist in diagnosis and management of children with mucopolysaccharidoses.

Objective: Mucopolysaacharidoses (MPS) represent a spectrum of disorders characterized by the genetic deficiency of specific lysosomal enzymes occurring in as many as 1 in 10,000 live births and resulting in the accumulation of glycosaminoglycans within cells throughout the body. Children have highly variable, multi-systemic involvement that nearly always involves manifestations of the head and neck including recurrent otitis, hearing loss, upper airway obstruction, and characteristic coarse facial features. This places the otolaryngologist in a prime position for early recognition and initiation of treatment.

Determining pseudo-equilibrium of montmorillonite colloids in generation and sedimentation experiments as a function of ionic strength, cationic form, and elevation.

Colloid generation and sedimentation experiments were carried out on Na- and Ca-montmorillonite in order to verify whether pseudo-equilibrium concentrations are reached at the same level in both types of experiments. The size and concentration of colloidal Na- and Ca-montmorillonite particles were monitored as a function of time and distance from the colloid bed in different ionic strength solutions. A stable pseudo-equilibrium concentration was reached after time in generation and sedimentation experiments.

Going the extra mile: beyond health teaching to political involvement.

Topic: Addressing community health problems through political involvement.

Purpose And Sources Of Information: This article describes how a group of RN-BSN students completing an assigned community-assessment and health-teaching project in a small, rural, southern county exceeded course requirements to address a significant community health problem. Specifically, after documenting a high rate of dental caries among local children and consulting with state officials and other experts, these students involved themselves in local politics in an effort to persuade county officials to implement community water fluoridation.

Uranium colloid analysis by single particle inductively coupled plasma-mass spectrometry.

Uranium single particle analysis has been performed by inductively coupled plasma-mass spectrometry (ICP-MS) and the performances are compared with that provided by scanning electron microscopy and single particle counting. The transient signal induced by the flash of ions due to the ionisation of an uranium colloidal particle in the plasma torch can be detected and measured for selected uranium ion masses ((238)U(+), (235)U(+) or (254)[(238)U(16)O](+)) by the mass spectrometer. The signals recorded via time scanning are analysed as a function of particle size or fraction of the studied element or isotope in the colloid phase.

Kinetic determination of critical coagulation concentrations for sodium- and calcium-montmorillonite colloids in NaCl and CaCl2 aqueous solutions.

The stability of the sodium and calcium forms of montmorillonite was studied at different NaCl and CaCl2 concentrations. The aggregation kinetics was determined from the decrease in particle concentration with time at different electrolyte concentrations. The DLVO theory defines the critical coagulation concentration (CCC) value as the electrolyte concentration that balances the attractive and repulsive potential energies between the particles, making aggregation diffusion-controlled.

Temperature effect on the stability of bentonite colloids in water.

The stability of natural bentonite suspensions has been investigated as a function of temperature at pH 9 and ionic strength 10(-3) M. The sedimentation rate of the particles is directly related to their stability. The sedimentation kinetics was determined by examining the variation of particle concentration in solution with time.

Three-block bi-focal PLS (3BIF-PLS) and its application in QSAR.

When X and Y are multivariate, the two-block partial least squares (PLS) method is often used. In this paper, we outline an extension addressing a special case of the three-block (X/Y/Z) problem, where Z sits "under" Y. We have called this approach three-block bi-focal PLS (3BIF-PLS).

Using chemometrics for navigating in the large data sets of genomics, proteomics, and metabonomics (gpm).

This article describes the applicability of multivariate projection techniques, such as principal-component analysis (PCA) and partial least-squares (PLS) projections to latent structures, to the large-volume high-density data structures obtained within genomics, proteomics, and metabonomics. PCA and PLS, and their extensions, derive their usefulness from their ability to analyze data with many, noisy, collinear, and even incomplete variables in both X and Y. Three examples are used as illustrations: the first example is a genomics data set and involves modeling of microarray data of cell cycle-regulated genes in the microorganism Saccharomyces cerevisiae.

Phenology of Lygus lineolaris (Hemiptera: Miridae) in Minnesota June-bearing strawberries: comparison of sampling methods and habitats.

Field studies were conducted in southeastern Minnesota from 2000 to 2002 to determine the phenology of Lygus lineolaris in various habitats and to compare yellow and white sticky traps as a sampling method for adult L. lineolaris. Strawberry fields were sampled for L.

Comparison of economic and plant phenology-based thresholds for management of Lygus lineolaris (Hemiptera: Miridae) in Minnesota strawberries.

Field studies were conducted in southeastern Minnesota, 2000-2002, to assess damage potential and management options for adult Lygus lineolaris (Palisot de Beauvois) in June-bearing strawberries (Fragaria x ananassa). The first study was designed to assess the efficacy of a published economic threshold for L. lineolaris nymphs compared with a plant phenology-based threshold management program, targeted at L.

Megavariate analysis of hierarchical QSAR data.

Multivariate PCA- and PLS-models involving many variables are often difficult to interpret, because plots and lists of loadings, coefficients, VIPs, etc, rapidly become messy and hard to overview. There may then be a strong temptation to eliminate variables to obtain a smaller data set. Such a reduction of variables, however, often removes information and makes the modelling efforts less reliable.

Statistical molecular design, parallel synthesis, and biological evaluation of a library of thrombin inhibitors.

A library of thrombin inhibitors has been designed using statistical molecular design. An aromatic scaffold was used, with three varied positions corresponding to three pockets at the active site of thrombin (the S-, P-, and D-pockets). The selection was performed in the building block space, and previously acquired data were included in the design procedure.

The Escherichia coli SeqA protein binds specifically to two sites in fully and hemimethylated oriC and has the capacity to inhibit DNA replication and affect chromosome topology.

The SeqA protein was identified as a factor that prevents reinitiation of newly replicated, hemimethylated origins. SeqA also seems to inhibit initiation of fully methylated origins, thus contributing to the regulation of chromosomal replication. The SeqA protein was found to bind to two sites in the left part of the origin, near the AT-rich region where strand separation takes place during initiation of replication.

Statistical molecular design of building blocks for combinatorial chemistry.

The reduction of the size of a combinatorial library can be made in two ways, either base the selection on the building blocks (BB's) or base it on the full set of virtually constructed products. In this paper we have investigated the effects of applying statistical designs to BB sets compared to selections based on the final products. The two sets of BB's and the virtually constructed library were described by structural parameters, and the correlation between the two characterizations was investigated.