acetone/dental caries

Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and

A high-resolution absorption spectrum of gaseous acetone near 8.2 μm has been taken using both Fourier transform and quantum cascade laser (QCL)-based infrared spectrometers. Absolute absorption cross sections within the 1215-1222 cm(-1) range have been determined, and the spectral window around

A direct measurement for the rate constant of the acetone dissociation reaction (CH3COCH3 = CH3CO + CH3) was conducted behind reflected shock wave, utilizing a sub-ppm sensitivity CO diagnostic achieved by cavity-enhanced absorption spectroscopy (CEAS). The current experiment eliminated the

A portable and compact device is demonstrated for measuring acetone in breath samples. The device features a 7 cm long high finesse optical cavity as an optical sensor that is coupled to a miniature adsorption preconcentrator containing 0.5 g of polymer material. Acetone is trapped out of breath and

We report the synthesis and characterization of tantalum-boronate trimetallic clusters of general formula {[Cp*Ta](3)(μ(2)-RB(O)(2))(3)(μ(2)-OH)(μ(2)-O)(2)(μ(3)-OH)} (R= 4-(C(6)H(5))(C(6)H(4)) (Ta(3)-4Ph), 4-(C(6)H(5)O)(C(6)H(4)) (Ta(3)-4OPh), 4-(C(7)H(7)O)(C(6)H(4)) (Ta(3)-4OBn),

We employed a single-mode, widely tunable (~300 cm−1) external-cavity quantum cascade laser operating around 8 µm for broadband direct absorption spectroscopy and wavelength modulation spectroscopy where a modulation frequency of 50 kHz was employed with high modulation amplitudes of up

We report a study on the cavity ringdown spectroscopy of acetone in both the ultraviolet (UV) and the near-infrared (NIR) spectral regions to explore the potential for development of a breath analyzer for disease diagnostics. The ringdown spectrum of acetone in the UV (282.4-285.0 nm) region is

The weak absorption spectra of isoprene and acetone have been measured in the wavelength range of 261-275 nm using cavity ringdown spectroscopy. The measured absorption cross-sections of isoprene in the wavelength region of 261-266 nm range from 3.65 × 10⁻²¹ cm².molecule⁻¹ at 261 nm to 1.42 × 10⁻²¹

Macrocyclic calixarene molecules were modified with functional groups of different polarities at the upper rim and subsequently grafted to mesoporous silica supports through a single Si atom linker. The resulting materials were characterized by thermogravimetric analysis, UV-visible spectroscopy,

Adhesion of xerogel dressings prepared on Eudragit-E 100, methylcellulose and glycerol compositions in acetone/water mixtures, remains within the range of 317-967 g, after addition of polyvinylpyrrolidone (PVP), it increases to 633-1200 g. Dissolution time of dressings in water amounts to 6 h, in

The geometry and energetics of the N-H…O=C hydrogen bond (H-bond) are important to understand the stability and flexibility of biomolecules, such as protein and DNA. Jet-cooled pyrrole-cyclopentanone (Py-Cp) binary clusters are appropriate models to investigate the N-H…O=C H-bond from a microscopic

Breath analysis offers a promising method of noninvasive analyses of volatile metabolites and xenobiotics present in human body. Isoprene is one of the highest abundant volatile organic compounds (VOCs) present in human exhaled breath. Breath isoprene (50-200 part per billion by volume (ppbv) or

PtO2 nanocatalysts-loaded SnO2 multichannel nanofibers (PtO2-SnO2 MCNFs) were synthesized by single-spinneret electrospinning combined with apoferritin and two immiscible polymers, i.e., poly(vinylpyrrolidone) and polyacrylonitrile. The apoferritin, which can encapsulate nanoparticles within a small

A robust method is demonstrated to measure acetone in human breath at sub parts-per-million by volume (ppmv) concentrations using diode laser cavity enhanced absorption spectroscopy. The laser operates in the near-infrared at about 1690 nm probing overtone transitions in acetone in a spectral region