Characteristic multimodal imaging of medication-related osteonecrosis of the jaw : comparison between oral and parenteral routes of medication administration

Background: To assess multimodal imaging features of medication-related osteonecrosis of the jaw (MRONJ) and to analyze the differences between oral and parenteral routes of medication administration. We retrospectively reviewed panoramic radiographs, CT, MRI, and bone scintigraphy of patients with MRONJ. Material/Methods: A retrospective study was conducted in 16 patients with MRONJ who underwent panoramic radiography, CT, MRI, and bone scintigraphy. Statistical analysis for the comparison between routes of medication administration and multimodal imaging features was performed with the Pearson's c2 test. Results: The percentage of cases with sequestrum separation was 25.0% (4/16 cases) on panoramic radiography and 81.3% (13/16 cases) on CT. The percentage of cases with periosteal bone proliferation on CT was 41.7% (5/12 cases) in the oral route of administration vs. 100% (4/4 cases) in the parenteral route of administration (p=0.042). The percentage of cases with spread of soft tissue inflammation to buccal and other spaces on CT and MRI was 33.3% (4/12 cases) in the oral route of administration vs. 100% (4/4 cases) in the parenteral route of administration (p=0.021). Conclusions: The sequestrum separation on panoramic radiography in patients with MRONJ was unclear in comparison to CT. Furthermore, characteristic CT findings of patients with MRONJ in the parenteral administration group were periosteal bone proliferation and spread of soft tissue inflammation to buccal and other spaces

Diffusion-weighted imaging in the oral and maxillofacial region : usefulness of apparent diffusion coefficient maps and maximum intensity projection for characterization of normal structures and lesions

Background: The aim of this study was to investigate diffusion-weighted imaging (DWI) in the oral and maxillofacial region, with a special focus on the usefulness of apparent diffusion coefficient (ADC) maps and maximum intensity projection (MIP) for characterization of normal structures and lesions. Material/Methods: Thirty-five patients who underwent magnetic resonance imaging (MRI) for diagnosis of oral and maxillofacial lesions were included in this prospective study. DWI was performed on a 1.5 T unit, with b factor of 0 and 800 s/mm2; moreover, ADC maps were generated. ADC values were measured for normal structures, odontogenic infections, squamous cell carcinomas (SCC), and hemangiomas. Results: As regards the normal structures, the mean ADC value of the cerebrospinal fluid (3.65±0.60×10-3 mm2/s) in the upper neck area was higher than that of the spinal cord (0.74±0.15×10-3 mm2/s, P=0.000), lymph nodes (0.87±0.17×10-3 mm2/s, P=0.000), and Waldeyer’s ring (0.92±0.29×10-3 mm2/s, P=0.000). The mean ADC value of hemangiomas (1.52±0.31×10-3 mm2/s) was higher than that of odontogenic infections (0.85±0.36×10-3 mm2/s, P=0.034) and SCC (1.38±0.22×10-3 mm2/s, P=0.840). Furthermore, MIP (DWI) showed the normal structures and lesions in the oral and maxillofacial region in an improved way. Conclusions: DWI, ADC maps, and MIP can be used to characterize and differentiate normal structures and lesions in the oral and maxillofacial region

Evolución del capital humano a través de las teorías administrativas: buscando al nuevo artesano organizacional

El objetivo de este trabajo es el de analizar, mediante la evaluación de una revisión teórica, la forma en que se ha vislumbrado el capital humano, y su evolución, en las teorías administrativas hasta las modernas y qué es lo que se ha necesita para utilizarlo en su máximo potencial. Por lo que, se propuso la idea de una evolución del capital humano que se ha debido a un impulso causado por la búsqueda de nuevos artesanos de las organizaciones, capaces de resolver los problemas de éstas. Concluyendo, en la contribución del capital humano en las teorías, reconociendo su complejidad, su potencial para generar una mayor productividad y ventaja competitiva, y siendo el principal motor de toda organización, el nuevo artesano organizacional

EVOLUCIÓN DEL CAPITAL HUMANO A TRAVÉS DE LAS TEORÍAS ADMINISTRATIVAS: BUSCANDO AL NUEVO ARTESANO ORGANIZACIONAL

El objetivo de este trabajo es el de analizar, mediante la evaluación de una revisión teórica, la forma en que se ha vislumbrado el capital humano, y su evolución, en las teorías administrativas hasta las modernas y qué es lo que se ha necesita para utilizarlo en su máximo potencial. Por lo que, se propuso la idea de una evolución del capital humano que se ha debido a un impulso causado por la búsqueda de nuevos artesanos de las organizaciones, capaces de resolver los problemas de éstas. Concluyendo, en la contribución del capital humano en las teorías, reconociendo su complejidad, su potencial para generar una mayor productividad y ventaja competitiva, y siendo el principal motor de toda organización, el nuevo artesano organizacional. Palabras claves: capital humano, teorías administrativas, potencial, artesano

Antenna System Composed of T-Shaped Elements Coupled to an Open Radial Waveguide

An antenna system composed of an activated open radial waveguide (RadWG) and parasitic T-shaped elements is proposed as a high-gain antenna, where the radiation beam is steerable around the system axis. The T-shaped elements are proximity-coupled to the RadWG. It is found that the upper round plate for the RadWG contributes to forming a desirable beam and increasing the gain. The beam steering with a gain of greater than targeted 9 dBi in 16 azimuthal directions is obtained by changing the location of open-state T-shaped elements whose height is 0.18 wavelength. Effects on the radiation characteristics of the system parameters, including the RadWG height, upper round plate diameter, ground plane diameter, and number of open-state T-shaped elements, are also analyzed and discussed

Enhancement of the extraction of lanthanide(III) with 2- thenoyltrifluoroacetone in the presence of foreign metal(III) ions: Coextraction of light lanthanide(III) with Al3+, Sc3+ and Fe 3+

金沢大学大学院自然科学研究科物質情報解析Enhancement of the extraction, or coextraction of lanthanide(III) (Ln) with metal(III) ions (M3+) such as Al3+, Sc3+, and Fe3+ was found in a typical chelate extraction system of 2-thenoyltrifluoroacetone (Htta)-benzene. The distribution ratio of La 3+ was enhanced by a factor of 6 with 3.0 x 10-2 M Al 3+, while that of Lu3+ was not affected at all. The magnitude of the coextraction decreased with the atomic number of Ln. Equilibrium analysis and spectroscopic studies indicated that the coextraction was ascribed to the formation of the 1:1 adduct between Ln(tta)3 and M(tta)3 extracted into the organic phase. The overall equilibrium of the coextraction was expressed as Ln3+ + M3+ + 6 Htta org ⇌ Ln(tta)3(M(tta)3)org + 6 H+

Structural variations in parotid glands induced by radiation therapy in patients with oral carcinoma observed on contrast-enhanced computed tomography

Background: Xerostomia is one of the commonest radiation-induced complications in patients with head and neck carcinoma. The aim of this study was to assess structural variations in parotid glands induced by radiation therapy in patients with oral carcinoma with contras-enhanced computed tomography (CECT). Material/Methods: A retrospective study was performed in 41 patients with oral carcinoma who underwent CECT for head and neck malignancies before and after radiotherapy. We analyzed the relationship between parotid density variations, parotid volume change, as seen on CECT, and the mean radiation dose applied to the parotid glands in patients with oral carcinoma immediately after radiotherapy, and 2 and 3 years later. Results: Immediately after radiotherapy, high-density changes on contrast-enhanced CT were observed in 70.5% of the irradiated parotids. Low-density changes due to fat degeneration were seen in 46.2% and 72.2% of the irradiated parotids 2 and 3 years after radiotherapy, respectively. The mean dose applied to the parotids with the low-density changes and without such changes 3 years after radiotherapy was 46.0 Gy and 27.7 Gy, respectively (p=0.049). Furthermore, parotid shrinkage was observed in 63.6% of the irradiated parotids. Conclusions: This study suggests that the structural variations in parotid glands induced by radiotherapy included high-density changes that were observed immediately after radiotherapy and low-density changes that were seen at late follow-up. This study should be useful for clinicians in the assessment of radiation-induced injuries in the parotids with respect to early prediction of xerostomia

Nanostructures from self-assembling triazine tertiary amine N-oxide amphiphiles

A new set of amphiphilic tertiary amine N-oxides has been prepared and their self-assembly properties observed in aqueous solution by tensiometry, dynamic and static light scattering. X-ray crystallographic analysis of parent amines and sulfoxide congeners indicates the formation of hydrogen bonded dimers as the primary assembly unit for formation of vesicles in preference to the compact micelles typical of lauryl dimethylamine N-oxide (LDAO). 6-Benzyloxy-N,N'-bis(5-diethylaminopentylamine oxide)[1,3,5]triazine-2,4-diamine forms a 1 μm vesicle observed to entrap fluorescein. The [1,3,5]triazine core thus allows variation of the new self-assembled structures from nano- to micrometre length scales

Spectrally-resolved UV photodesorption of CH4 in pure and layered ices

Context. Methane is among the main components of the ice mantles of insterstellar dust grains, where it is at the start of a rich solid-phase chemical network. Quantification of the photon-induced desorption yield of these frozen molecules and understanding of the underlying processes is necessary to accurately model the observations and the chemical evolution of various regions of the interstellar medium. Aims. This study aims at experimentally determining absolute photodesorption yields for the CH4 molecule as a function of photon energy. The influence of the ice composition is also investigated. By studying the methane desorption from layered CH4:CO ice, indirect desorption processes triggered by the excitation of the CO molecules is monitored and quantified. Methods. Tunable monochromatic VUV light from the DESIRS beamline of the SOLEIL synchrotron is used in the 7 - 13.6 eV (177 - 91 nm) range to irradiate pure CH4 or layers of CH4 deposited on top of CO ice samples. The release of species in the gas phase is monitored by quadrupole mass spectrometry and absolute photodesorption yields of intact CH4 are deduced. Results. CH4 photodesorbs for photon energies higher than ~9.1 eV (~136 nm). The photodesorption spectrum follows the absorption spectrum of CH4, which confirms a desorption mechanism mediated by electronic transitions in the ice. When it is deposited on top of CO, CH4 desorbs between 8 and 9 eV with a pattern characteristic of CO absorption, indicating desorption induced by energy transfer from CO molecules. Conclusions. The photodesorption of CH4 from the pure ice in various interstellar environments is around 2.0 x 10^-3 molecules per incident photon. Results on CO-induced indirect desorption of CH4 provide useful insights for the generalization of this process to other molecules co-existing with CO in ice mantles