Verification of morphological and physical properties for the development of a lung substitute phantom using microspheres.

This paper proposes a new concept of phantom development, along with the utilization of new materials that can reproduce lung morphology and density. A lung substitute phantom using microspheres was fabricated; then, its dosimetric utility in radiotherapy was investigated, during which the density was adjusted to closely resemble the morphology of the actual human lung. Microspheres were used to reproduce alveoli, which are the main components of the lung. By changing the ratio of urethane, which is commonly used in soft tissue phantoms, to microspheres, we reproduced the density change of the lungs due to respiration. Here, we fabricated two slab-like lung substitutes to emulate commercially used phantoms. Although there is room for improvement in terms of practicality, the substitutes were easy to fabricate. Microscopic observation of the cut surface of the phantoms showed that the morphology of the phantoms mimicked the alveoli more faithfully than commercial phantoms. Furthermore, to compensate for the energy-independent mass attenuation and mass collision inhibition ability required by the tissue substitute phantom, we examined the physical properties of the phantom and confirmed that there was negligible energy dependence.

The Association of Oral Function with Oral Health-Related Quality of Life in University Students: A Cross-Sectional Pilot Study.

The aim of this cross-sectional study was to investigate the association between oral function and oral health-related quality of life (OHRQoL) in healthy university students. Oral functions and OHRQoL (General Oral Health Assessment Index; GOHAI) were investigated in 58 healthy university students. Oral functions, such as tongue pressure, tongue-lip motor function, occlusal force, and masticatory function, were examined. The participants were divided into two groups based on low and high GOHAI scores. Information about oral health, dental caries treatment history, insomnia, and personality and lifestyle was obtained using a self-reported questionnaire. Oral mucosal wetness scores and tongue-lip motor functions (oral diadochokinesis /ka/) were significantly decreased in the low GOHAI score group compared to the high GOHAI score group (p = 0.001 and p = 0.017, respectively). In the logistic regression model, the GOHAI score was independently associated with the oral mucosal wetness score (odds ratio (OR) = 0.622; 95% confidence interval (CI), 0.411-0.941; p = 0.025) and oral diadochokinesis /ka/ (OR = 0.376; 95% CI, 0.170-0.832; p = 0.016). Our study demonstrated the presence of low oral function in university students and suggested its association to low OHRQoL in this population.

Divalent dirhodium imido complexes: formation, structure, and alkyne cycloaddition reactivity.

Dirhodium amido complexes [(Cp*Rh)2(mu2-NHPh)(mu2-X)] (X = NHPh (2), Cl (3), OMe (4); Cp* = eta5-C5Me5) were prepared by chloride displacement of [Cp*Rh(mu2-Cl)]2 (1) and have been used as precursors to a dirhodium imido species [Cp*Rh(mu2-NPh)RhCp*]. The imido species can be trapped by PMe3 to give the adduct [Cp*Rh(mu2-NPh)Rh(PMe3)Cp*] (5) and undergoes a formal [2 + 2] cycloaddition reaction with unactivated alkynes to give the azametallacycles [Cp*Rh(mu2-eta2:eta3-R1CCR2NPh)RhCp*] (R1 = R2 = Ph (6a), R1 = H, R2 = t-Bu (6b), R1 = H, R2 = p-tol (6c)). Isolation of a relevant unsaturated imido complex [Cp*Rh(mu2-NAr)RhCp*] (7) was achieved by the use of a sterically hindered LiNHAr (Ar = 2,6-diisopropylphenyl) reagent in a metathesis reaction with 1. X-ray structures of 2, 6a, 7 and the terminal isocyanide adduct [Cp*Rh(mu2-NAr)Rh(t-BuNC)Cp*] (8) are reported.