Relationship between friction force and orthodontic force at the leveling stage using a coated wire

The relationship between orthodontic force and friction produced from an archwire and brackets affects the sliding of the wire in the leveling stage. Objective: The purpose of this study was to evaluate the relationship between force and friction in a small esthetic nickel-titanium (Ni-Ti) wire. Material and Methods: Five esthetic wires (three coated and two plated) and two small, plain Ni-Ti wires (0.012 and 0.014 inches) were used. We performed a three-point bending test according to ISO 15841 and the drawing test with a dental arch model designed with upper linguoversion of the lateral incisor in the arch (displacements of 0.5, 1.0, 2.0 and 3.0 mm), and evaluated the relationship between them. Results: Unloading bending forces of all wires at displacements of less than 1.0 mm were larger than friction forces, but all friction forces at displacements exceeding 2.0 mm were larger than unloading bending forces. The arch likely expands when displacement from the proximal brackets exceeds 1.0 mm. The friction force of a martensite 0.014-inch Ni-Ti wire was significantly greater than those of the other esthetic and austenitic wires. Conclusions: A wire with the smallest possible friction force should be used in cases with more than 1.0 mm displacement. .

Relationship between friction force and orthodontic force at the leveling stage using a coated wire.

UNLABELLED: The relationship between orthodontic force and friction produced from an archwire and brackets affects the sliding of the wire in the leveling stage. OBJECTIVE: The purpose of this study was to evaluate the relationship between force and friction in a small esthetic nickel-titanium (Ni-Ti) wire. MATERIAL AND METHODS: Five esthetic wires (three coated and two plated) and two small, plain Ni-Ti wires (0.012 and 0.014 inches) were used. We performed a three-point bending test according to ISO 15841 and the drawing test with a dental arch model designed with upper linguoversion of the lateral incisor in the arch (displacements of 0.5, 1.0, 2.0 and 3.0 mm), and evaluated the relationship between them. RESULTS: Unloading bending forces of all wires at displacements of less than 1.0 mm were larger than friction forces, but all friction forces at displacements exceeding 2.0 mm were larger than unloading bending forces. The arch likely expands when displacement from the proximal brackets exceeds 1.0 mm. The friction force of a martensite 0.014-inch Ni-Ti wire was significantly greater than those of the other esthetic and austenitic wires. CONCLUSIONS: A wire with the smallest possible friction force should be used in cases with more than 1.0 mm displacement.

[Pulmonary alveolar proteinosis detected by a nodular lesion on chest computed tomography].

A 74-year-old woman was admitted to our hospital for further examination of chest X-ray abnormality. The chest computed tomography (CT) revealed a nodular lesion (1.0 cm in diameter) in right lung. Bronchoscopic biopsy showed no malignant cells and bronchoalveolar lavage fluid was not milky white. We performed video-assisted thoracic surgery and a tumor was resected. Histologically, dilated alveolar areas was filled with eosinophilic materials. This finding was compatible with pulmonary alveolar proteinosis (PAP). The characteristic CT finding of PAP is ground glass opacities in both lungs with thickened alveolar septa (so-called crazy-paving appearance). The CT findings of this case (unilateral, single nodular lesion) are very rare, so we report this case with references to the literatures.

Preparation, photocatalytic activities, and dye-sensitized solar-cell performance of submicron-scale TiO2 hollow spheres.

We prepared submicron-scale spherical hollow particles of anatase TiO2 by using a polystyrene-bead template. The obtained particles were very uniform in size, with a diameter of 490 nm and a shell thickness of 30 nm. The Brunauer-Emmett-Teller surface area measurements revealed a large value of 70 m2/g. The photocatalytic property was investigated by the complete decomposition of gaseous isopropyl alcohol under UV irradiation. It was indicated that the activity of the hollow spheres was 1.8 times higher than that of the conventional P25 TiO2 nanoparticles with a diameter of 30 nm. Furthermore, we fabricated a dye-sensitized solar cell (DSC) using an electrode of the TiO2 hollow spheres, and examined the photovoltaic performance under simulated sunlight. Although the per-area efficiency was rather low (1.26%) because of a low area density of TiO2 on the electrode, the per-weight efficiency was 2.5 times higher than those of the conventional DSCs of TiO2.

Effect of caffeine on the multiplication of DNA and RNA viruses.

The present study examined the effect of caffeine on RNA and DNA viruses, revealing that it inhibits the multiplication of both. In the presence of caffeine, the progeny virus yield of both herpes simplex virus type 1 (HSV-1) and poliovirus decreased with increasing concentrations of the reagent, although HSV-1 was much more sensitive than poliovirus. The influenza virus was not affected by caffeine at the same concentrations. None of the viruses were directly inactivated by caffeine at the tested concentrations. Characterization of the mode of action of caffeine against HSV-1 infection revealed that the addition of the reagent at 10 h post-infection significantly affected the formation of progeny virus, indicating that caffeine can inhibit the multiplication of HSV-1 during the step(s) following the completion of viral DNA replication and the formation of nucleocapsids. In addition, the reagent selectively enhanced the cytopathic effects and cell death of the infected cells over uninfected cells, suggesting that the antiviral action of caffeine against HSV-1 is, at least in part, the result of accelerated degeneration of the infected cells.

Endobronchial ultrasonography using a guide sheath increases the ability to diagnose peripheral pulmonary lesions endoscopically.

STUDY OBJECTIVE: To assess the ability of endobronchial ultrasonography (EBUS) using a guide sheath (EBUS-GS) to diagnose peripheral pulmonary lesions. METHOD: We devised a technique for EBUS-GS covering a miniature probe, and 150 lesions were evaluated in a prospective open study. In this procedure, the probe covered by a guide sheath is introduced into the lesion via the working channel of a bronchoscope. The probe is withdrawn, while the guide sheath is left in situ. A brush or biopsy forceps is introduced through the guide sheath into the lesion. RESULTS: One hundred sixteen of 150 EBUS-GS procedures (77%) were diagnostic. Cases in which the probe was located within the lesion had a significantly higher diagnostic yield (105 of 121 cases, 87%) than when the probe was located adjacent to it (8 of 19 cases, 42%) [p < 0.0001, chi(2)]. The diagnostic yield from EBUS-GS in lesions 10 to 15 to 20 to

Analysis of the internal structure of peripheral pulmonary lesions using endobronchial ultrasonography.

STUDY OBJECTIVE: To correlate the internal structure of peripheral pulmonary lesions, as visualized by endobronchial ultrasonography (EBUS), and the histology of the surgical specimen to develop a classification system for distinguishing benign from malignant lesions by EBUS. DESIGN: Retrospective review. SETTING: A national hospital. PATIENTS: One hundred twenty-four patients with peripheral pulmonary lesions who had undergone EBUS in whom a definitive histologic diagnosis was made. In 69 patients, EBUS findings were correlated with the histology of a surgical specimen. INTERVENTION: EBUS was performed by a miniature probe (20-MHz) introduced up to the lesion through a channel in a bronchoscope. RESULTS: Three classes and six subclasses of lesions were identified by EBUS based on the internal structure of the lesion, focusing on internal echoes, vascular and bronchial patency, and the morphology of the hyperechoic areas, reflecting air in the alveoli and bronchioles. The classes of lesions are as follows: type I, homogeneous pattern (type Ia, with patent vessels and patent bronchioles; type Ib, without vessels and bronchioles); type II, hyperechoic dots and linear arcs pattern (type IIa, without vessels; type IIb, with patent vessels); and type III, heterogeneous pattern (type IIIa, with hyperechoic dots and short lines; type IIIb, without hyperechoic dots and short lines). Twenty-three of 25 type I lesions (92.0%) were benign, while 98 of 99 type II and III lesions (99.0%) were malignant. Twenty-one of 24 type II lesions (87.5%) were well-differentiated adenocarcinomas, and all type IIIb lesions were malignant, including 18 poorly differentiated adenocarcinomas (81.8%). CONCLUSIONS: EBUS permits the visualization of the internal structure of peripheral pulmonary lesions, and this information suggests the histology of the lesion.