Psychophysical and Rheological Investigation of Toothpaste Tube Squeezability: A People-Centric Approach.

In this work, toothpaste tube squeezability was tested by three different methods: assessment by a human panel, a tactile glove, and several purely instrumental tests. The panelists characterized squeezability in terms of the acceptability of the product. The tactile glove was utilized to determine the maximum grip forces (G) applied by the same panelists during their assessment.

Pilot clinical study to evaluate the efficacy of a professionally delivered high fluoride varnish on erosive tooth wear in an in-situ model.

Objectives: The aim for this pilot study was to investigate the effect of a sodium fluoride varnish on step height measured by a profilometer from human enamel worn by healthy volunteers with a novel in situ/ex vivo erosion design.

Method: Healthy volunteers aged 18-70 years wore a palatal splint containing 8 human enamel samples and underwent two 3-day treatment periods for 6 h a day with a varnish containing sodium fluoride at 22,600 ppm and the control with the same ingredients but without fluoride. Each splint contained 4 polished and 4 unpolished samples.

Dopamine-mediated striatal activity and function is enhanced in GlyRα2 knockout animals.

The glycine receptor alpha 2 (GlyRα2) is a ligand-gated ion channel which upon activation induces a chloride conductance. Here, we investigated the role of GlyRα2 in dopamine-stimulated striatal cell activity and behavior. We show that depletion of GlyRα2 enhances dopamine-induced increases in the activity of putative dopamine D1 receptor-expressing striatal projection neurons, but does not alter midbrain dopamine neuron activity.

The influence of age, gender and race/ethnicity on the composition of the human axillary microbiome.

Objective: The microbial community plays an important role in the generation of human axillary odour by transforming odourless natural secretions into volatile odorous molecules. A limited number of traditional culturing methods and molecular based research have been performed to characterize the human axillary microbiome in small collection sample sizes. Moreover, only a few have considered the interpersonal variations across age, gender or race/ethnicity, and none have included all three variables within one single study.

Short- and Long-Term Effects of a Dentifrice Containing Dual Zinc plus Arginine on Intra-Oral Halitosis: Improvements in Breath Quality.

Objectives: These studies aimed to assess the short-term (12-hour, single use) and long-term (four weeks, continuous use) efficacy of a new Dual Zinc plus Arginine dentifrice against intra-oral halitosis versus a negative control.

Methods: Two clinical studies were conducted to assess the dentifrice: a four-week, continuous use parallel design versus a negative control and a single use crossover design versus a negative control. Both studies used organoleptic and hedonic odor judge scores measured 12 hours overnight after product use as the primary efficacy variable.

Image Correlation Spectroscopy with Second Harmonic Generating Nanoparticles in Suspension and in Cells.

The absence of photobleaching, blinking, and saturation combined with a high contrast provides unique advantages of higher-harmonic generating nanoparticles over fluorescent probes, allowing for prolonged correlation spectroscopy studies. We apply the coherent intensity fluctuation model to study the mobility of second harmonic generating nanoparticles. A concise protocol is presented for quantifying the diffusion coefficient from a single spectroscopy measurement without the need for separate point-spread-function calibrations.

Dynamics of the phospholipid shell of microbubbles: a fluorescence photoselection and spectral phasor approach.

The lipid organization of microbubbles is important in many applications. By monitoring the photoselection and emission spectrum of the fluorescent probe Laurdan in perfluorobutane gas-filled DPPC microbubbles with a two-photon laser scanning microscope, we observed a transition to a more rigid lipid organization in 30 minutes to several hours.

Noninvasive measurement of reepithelialization and microvascularity of suction-blister wounds with benchmarking to histology.

We explored use of the suction-blister wound model in the assessment of not only epidermal regeneration but also pain, the microvascular response and bacteriology. The effects of topical zinc sulfate were studied to articulate the methodologies in this double-blind trial. One epidermal suction blister (10 mm) was induced on each buttock in 30 healthy volunteers (15 females:15 males) and deroofed on day 0.

Rapid and label-free optical detection of individual carbon air pollutant nanoparticulates in biomedical samples.

Carbonaceous particle exposure and air pollution in general lead to a multitude of adverse human health effects and pose multiple challenges in terms of exposure, risk and safety assessment. Highly desirable for fast screening are label-free approaches for detecting these particle types in biological or medical context. We report a powerful approach for detecting carbonaceous particles using photothermal pump-probe microscopy, which directly probes their strong light absorption.

A Comparative Study of Laboratory Dentifrice Abrasion Measuring Methods.

Objectives: Recently, a profilometry-based method for measuring toothpaste dentin abrasivity has been proposed to be equivalent to the traditional radiotracer RDA (relative dentin abrasion) procedure. This review outlines the findings and comparative assessment of laboratory studies used to measure the abrasivity of commercially available whitening dentifrices on human dentin. Traditional radiotracer and profilometry RDA-PE (Profilometry Equivalent) methods were assessed, with the objective of determining how they compare, and also to learn if the two techniques yield RDA values that are consistent with each other, specifically in ranking and potential for discrimination of three commercially available silica-based products.

Biocompatible Label-Free Detection of Carbon Black Particles by Femtosecond Pulsed Laser Microscopy.

Although adverse health effects of carbon black (CB) exposure are generally accepted, a direct, label-free approach for detecting CB particles in fluids and at the cellular level is still lacking. Here, we report nonincandescence related white-light (WL) generation by dry and suspended carbon black particles under illumination with femtosecond (fs) pulsed near-infrared light as a powerful tool for the detection of these carbonaceous materials. This observation is done for four different CB species with diameters ranging from 13 to 500 nm, suggesting this WL emission under fs near-infrared illumination is a general property of CB particles.

Coherent intensity fluctuation model for autocorrelation imaging spectroscopy with higher harmonic generating point scatterers-a comprehensive theoretical study.

We present a general analytical model for the intensity fluctuation autocorrelation function for second and third harmonic generating point scatterers. Expressions are derived for a stationary laser beam and for scanning beam configurations for specific correlation methodologies. We discuss free translational diffusion in both three and two dimensions.

A 12-week clinical study assessing the clinical effects on plaque metabolism of a dentifrice containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm fluoride.

Purpose: To evaluate the clinical effect on plaque metabolism of a dentifrice containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm fluoride compared to a commercially available dentifrice containing 1,450 ppm fluoride in a silica base.

Methods: A 12-week, parallel, randomized, double-blind study using 48 subjects was conducted at the Colgate-Palmolive Technology Center (Piscataway, NJ, USA).

In vivo effects of a new dentifrice containing 1.5% arginine and 1450 ppm fluoride on plaque metabolism.

Objective: This paper presents the results of a clinical study assessing the in vivo effects on plaque metabolism of a new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450 ppm fluoride compared to a commercially available dentifrice containing 1450 ppm fluoride alone.

Methods: A four-week, parallel, randomized, double-blind clinical study using 54 subjects was conducted at the New York University College of Dentistry Bluestone Center for Clinical Research.

In situ clinical effects of new dentifrices containing 1.5% arginine and fluoride on enamel de- and remineralization and plaque metabolism.

Objective: The primary objective of the three studies reported in this paper was to evaluate the effects of new dentifrices containing 1.5% arginine, an insoluble calcium compound, and fluoride for their ability to promote remineralization of demineralized enamel, and to prevent mineral loss from sound enamel specimens. A secondary objective was to determine the effects on plaque metabolism with respect to the conversion of arginine to ammonia and sucrose to lactic acid.

The development of a new desensitising mouthwash containing arginine, PVM/MA copolymer, pyrophosphates, and sodium fluoride--a hydraulic conductance study.

Objective: To investigate the ability of a novel mouthwash comprised of 0.8% arginine, PVM/MA copolymer, pyrophosphates, and 0.05% sodium fluoride in an alcohol-free base (Pro-Argin™ Mouthwash Technology) to reduce dentine permeability.

Fluorescence recovery after photobleaching on the confocal laser-scanning microscope: generalized model without restriction on the size of the photobleached disk.

Fluorescence recovery after photobleaching (FRAP) carried out on a confocal laser-scanning microscope (CLSM) performs well for photobleached disks that are large compared to the resolution of the bleaching beam. For smaller disks approaching this resolution, current FRAP models providing a closed-form solution do not allow one to extract the diffusion coefficient accurately. The new generalized disk model we present addresses this shortcoming by bringing into account the bleaching resolution and the total confocal imaging resolution.

Comparison of the effects on dentin permeability of two commercially available sensitivity relief dentifrices.

Objective: The in vitro effects of two commercial sensitivity relief dentifrices, one containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride as sodium monofluorophosphate (MFP), and the other containing 8% strontium acetate and 1040 ppm fluoride as sodium fluoride, in occluding dentin tubules and reducing dentin fluid flow were compared in a blinded study using hydraulic conductance (Flodec).

Methods: Human dentin segments were cut from extracted molars, mounted on acrylic blocks, etched, and connected to a Flodec to measure hydraulic conductance.

In vitro antibacterial efficacy of cetylpyridinium chloride-containing mouthwashes.

Objective: The objective of this study was to examine the ability of three CPC-containing mouthwashes to kill planktonic bacteria in an in vitro short-exposure assay.

Methods: This blind study was conducted on two common oral bacterial species: Aggregatibacter (Actinobacillus) actinomycetemcomitans and Streptococcus mutans. The following mouthwashes were tested: two containing 0.

Simvastatin interferes with process outgrowth and branching of oligodendrocytes.

Statins have attracted interest as a treatment option for multiple sclerosis (MS) because of their pleiotropic antiinflammatory and immunomodulatory effects. However, contradictory results have been described when they are applied to oligodendrocytes (OLGs), the cell type predominantly affected in MS. In this study we focus on the in vitro effect of statins on process outgrowth in OLN-93 cells, a well-characterized OLG-derived cell line, and primary cultures of neonatal rat OLGs.

Comparing the effects of brushing with a new gel-to-foam dentifrice to brushing with regular fluoride control dentifrices on viable bacteria levels in saliva.

Purpose: To compare the effects of a new gel-to-foam dentifrice to two standard fluoride control dentifrices on foam generation, levels of total viable anaerobes and total viable volatile sulfur compound (VSC)-producing bacteria in expectorate after brushing.

Methods: 36 subjects participated in this investigator-blind, randomized, crossover study. After a 1-week wash-out period prior to each product use, participants reported to the test site having refrained from oral hygiene, eating and drinking on the morning prior to the visit.

Analysis of mitochondrial pH and ion concentrations.

Detailed practical information is provided with emphasis on mapping cytosolic and mitochondrial pH, mitochondrial Na(+), and briefly also aspects related to mitochondrial Ca(2+) measurements in living cells, as grown on (un)coated glass coverslips. This chapter lists (laser scanning confocal) microscope instrumentation and setup requirements for proper imaging conditions, cell holders, and an easy-to-use incubator stage. For the daily routine of preparing buffer and calibration solutions, extensive annotated protocols are provided.

Measuring diffusion of lipid-like probes in artificial and natural membranes by raster image correlation spectroscopy (RICS): use of a commercial laser-scanning microscope with analog detection.

The heterogeneity in composition and interaction within the cellular membrane translates into a wide range of diffusion coefficients of its constituents. Therefore, several complementary microfluorimetric techniques such as fluorescence correlation spectroscopy (FCS), fluorescence recovery after photobleaching (FRAP) and single-particle tracking (SPT) have to be applied to explore the dynamics of membrane components. The recently introduced raster image correlation spectroscopy (RICS) offers a much wider dynamic range than each of these methods separately and allows for spatial mapping of the dynamic properties.

Structural and optical properties of DNA layers covalently attached to diamond surfaces.

Label-free detection of DNA molecules on chemically vapor-deposited diamond surfaces is achieved with spectroscopic ellipsometry in the infrared and vacuum ultraviolet range. This nondestructive method has the potential to yield information on the average orientation of single as well as double-stranded DNA molecules, without restricting the strand length to the persistence length. The orientational analysis based on electronic excitations in combination with information from layer thicknesses provides a deeper understanding of biological layers on diamond.