It is known that fractures are more likely to occur in altered teeth, particularly following restoration or endodontic repair; consequently, it is important to understand the structure of altered forms of dentin, the most abundant tissue in the human tooth, in order to better define the increased propensity for such fractures. Transparent (or sclerotic) dentin, wherein the dentinal tubules beco...

Organic nanoparticles made of a push-pull triarylamine dye with an average diameter of 60 nm, were prepared by reprecipitation. We study their photophysical properties by a combination of photothermal and fluorescence microscopy. Photothermal contrast provides a quantitative measure of the number of absorbers. The size of nanoparticles estimated from the absorption measurements was compared wit...

Under ultrasonic irradiation, organic fluorescence nanoparticles have been prepared by a reprecipitation method. Compared with single organic fluorophores, these nanoparticles are brighter, more stable against photobleaching and more water-soluble. They also have high room-temperature fluorescence quantum yields (approximately 20%) and a long fluorescence lifetime (approximately 0.2 micros). Ba...

Poly(3-hexylthiophene) (P3HT) nanoparticles (NPs) were prepared by a reprecipitation method. Hydrothermal processing applied external pressure to the pristine P3HT NPs at temperatures ranging from 60 to 150 °C. Optical absorption and photoluminescence (PL) spectra for the hydrothermally treated P3HT NPs varied markedly with the processing temperature. With increasing treatment temperature, the ...

Six lesions were made on the buccal surfaces of premolars. The volume percentage of mineral was determined as a function of depth by microradiography. Using the electron microprobe, the signals for Ca, Na, Mg, P and Cl were recorded as a function of depth both through the lesions and through the adjacent sound enamel. In the demineralized parts, there was a preferential loss of Na and a prefere...

Light-emitting 5,6,11,12-tetraphenylnaphthacene (rubrene) nanoparticles (NPs) prepared by a reprecipitation method were treated hydrothermally. The diameters of hydrothermally treated rubrene NPs were changed from 100 nm to 2 μm, depending on hydrothermal temperature. Photoluminescence (PL) characteristics of rubrene NPs varied with hydrothermal temperatures. Luminescence of pristine rubrene NP...

Magnesium-substituted fluorapatite powders were synthesized by hydrothermal method, and their sintering behavior was investigated by dilatometry in the temperature range 25-1100°C. Analysis of the obtained powders by X-ray diffraction and (31)P NMR spectroscopy showed that the powders consisted of a single apatite phase and no amorphous phase has been formed. Compared to pure fluorapatite, the ...

Arterior descending branch of coronary was occluded in 33 mongre I dogs under alpha-chloralose (80-100 mglkg iv). Nineteen animals exhibiting spontaneous ventriculiH ectopics with in half an hour of occlusion comprised Group I. while the remaining 14 animals unattended by ventricular ectopics were included in Group. II. Ten animals of Group I were subjected to left stellate ganglion blockade (L...

Developing organic chromophores with large two-photon absorption (TPA) in both organic solvents and aqueous media is crucial owing to their applications in solid-state photonic devices and biological imaging. Herein, a series of novel terpyridine-based quadrupolar derivatives have been synthesized. The influences of electron-donating group, type of conjugated bridge, as well as solvent polarity...

ISOKAWA, TODA and KUBOTA[1] etched fractured human dentin surfaces with a weak acid and observed that a part of the peritubular zone persisted as a recognizable tubular structure. The inner hypomineralized layer (SHROFF, WILLIAMSON and BERTAUD [2], SHROFF et al. [3] and TAKUMA [4]) which appeared in the tubular structure was assumed to play an important role. ISOKAWA et al. [1] also presumed di...