Search

While lingual nerve injury is a well-recognized complication of impacted mandibular wisdom tooth extraction, there are no studies on lingual nerve injury occurring as a complication of wisdom tooth germ extraction in teenage or preteen (aged 10 years or older) patients. Lingual nerve injuries with nerve loss are conventionally treated using autologous nerve grafts, among others. While some recent studies have reported nerve repair using a nerve conduit for peripheral nerve regeneration, many details regarding the objective postoperative course and indications for pediatric cases remain unclear. The purpose of this report was to assess the clinical course after repair using a nerve conduit (Nerbridge®) for peripheral nerve regeneration in the case of preteen patient with lingual nerve injury caused by mandibular wisdom tooth germ extraction. The patient was a 12-year-old boy who underwent right lingual nerve repair under general anesthesia. At approximately 4 months postoperatively, the patient's hypesthesia improved. This improvement continues to the present day. Because it is difficult to conduct medical interviews on the symptoms of lingual nerve injury when the patient is a child, making it impossible to accurately determine whether complications are present, it is important to undertake comprehensive diagnosis and obtain informed consent, including that of the child's guardian. Literature review and our experience in treating the present case suggest that the early use of a nerve conduit for peripheral nerve regeneration can be effective in promoting nerve function recovery. [ABSTRACT FROM AUTHOR]

Focuses on a study which developed a polarization-sensitive laser-light-scattering (LLS) method for smultaneous in situ measurements of properties of particulates formed in processing plasmas. Background on LLS; Methodology of the study; Results and discussion.

Arcing is a long-standing plasma-surface interaction issue, and the issue is currently being revived. This paper assesses the impact of arcing in fusion devices based on the observations in JT-60U, the Large Helical Device (LHD) and the linear divertor simulator NAGDIS-II. To investigate the first initiation process of arcing, field emission currents from several tungsten samples are measured. It is shownthat the field emission current increases significantly after tungsten is exposed to helium plasmas. A postmortem analysis of JT-60U tiles reveals that arcing phenomena occurred on carbon baffle plates inside the vacuum vessel in JT-60U. From the observation of the arc trails recorded on the baffle plate, the amount of eroded materials is discussed. The arcing seems to occur frequently on the inner baffles rather than the outer baffles. From LHD, it is shown that the arcing can be initiated on nanostructured tungsten even without transient events. The erosion of tungsten by arcing will become an important issue in a fusion reactor, where helium fluence is significantly increased. From the experiments in NAGDIS-II, it is shown that arcing can be initiated even without transient heat load when the target voltage is low enough, e.g. -500V. Frequent initiation of arcing annihilates the nanostructure growth due to helium plasma irradiation on the surface. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether intradermal administration of 5-aminolevulinic acid (5-ALA) could achieve a sufficient amount of protoporphyrin IX (PpIX) to induce photochemical reaction in chicken comb, the animal model of port wine stains (PWSs). Methods: PpIX accumulation after 5-ALA administration through intradermal or intravenous injection was monitored for 24 hours. Localization of PpIX was observed under a confocal microscope. The comb was exposed to red light after intradermal 5-ALA injection, and the subsequent changes were observed grossly and microscopically. Results: In the comb, PpIX accumulation achieved the peak level at 5 and 4 hours after intravenous or intradermal injection of 5-ALA, respectively, and was almost completely eliminated within 24 hours. A similar amount of PpIX was observed in both groups. While in the body skin, a lower level of PpIX was observed after intradermal injection. A confocal microscope showed that PpIX distributed evenly in comb dermis without significant difference between the two groups. The vascular structure in comb was disrupted after laser irradiation based on intradermal administration of 5-ALA. Conclusions: Intradermal injection of 5-ALA is a safer administration route that could achieve the equivalent of PpIX accumulation and destroy vasculature after PDT. It might be applicable to the clinical treatment of PWSs. [ABSTRACT FROM AUTHOR]

Abstract: A 3D magnetic inversion method using a conjugate gradient method (CG method) was developed for constructing 3D magnetization models of a volcanic edifice and applied to aeromagnetic anomalies of Izu-Oshima Volcano surveyed in 1986 and in 1997. The calculated results of the 1986 data show that the volcanic edifice of Izu-Oshima Volcano has a mean magnetization intensity ranging from 10.4 to 12.1 A/m. The derived 3D magnetic structure shows low magnetization zones beneath the west-northwest of the western caldera rim, beneath the west-southwest of Mt. Mihara and beneath Mt. Shiroishi. These features may be related with demagnetizations, reflecting a high thermal state due to magma activities in the 1986 eruption. The comparison between 3D magnetization models in 1986 and in 1997, indicates meaningful changes beneath the C-craters erupted in 1986, suggesting a recovery process of demagnetizations and a considerable decrease of magnetization intensities in the foot of Mt. Futago, indicative of demagnetizations. A derived magnetization model including Izu-Oshima Volcano and its surrounding sea areas clarifies the submerged volcanic edifices around Izu-Oshima Island, and suggests that the old volcanic edifices of Fudeshima, Gyojyanoiwaya, and Okata Volcanoes have been affected by eastward migrations due to massive intrusions of a dike-like structure inferred at the base of Izu-Oshima Volcano. [Copyright &y& Elsevier]

A new steady-state, low-energy, and high-flux ion beam test device has been developed to study erosion, re-deposition, and hydrogen retention mechanisms of plasma facing materials under high flux conditions. Source plasma was produced by electron cyclotron resonance discharge with 2.45 GHz microwave. Ion extraction was made by spherical multiaperture triode electrodes to obtain high ion flux at the focal point. Ion extraction aperture geometry was designed so that high current density can be obtained in the case of low energy (<500 eV) by applying high deceleration voltage. It was demonstrated that low-energy and high-flux ion beam can be produced by increasing deceleration voltage with the fixed acceleration voltage (beam energy). In the case of hydrogen beam energy of 300 eV, beam power density has rapidly increased with a deceleration voltage over accel-decel ratio 4, and maximum beam flux is 4.1 × 10[sup 20] H/m² s. On the other hand, maximum beam flux of 3.6 × 10[sup 21] H/m²s was obtained for 3 keV hydrogen beam. These fluxes are much higher than that of conventional mass analyzed ion beam (< 1.0 × 10[sup 20] H/m² s). [ABSTRACT FROM AUTHOR]

Describes how a narrow gap and high deceleration voltage affects the deflection angle and the beam characteristics for the geometrical focusing of a low-energy ion source by an aperture displacement technique. Two-dimensional power density profiles; Focal length and other beam characteristics; Analytical formula of steering angle.

In order fo obtain a high brightness ion beam from a plasma ion source in the low energy region (150 eV), the effects of sheath potential on the ion beam characteristics such as beam divergence and brightness have been studied experimentally. A bucket-type ion source (magnetic multicusp ion source) with an accel-decel triode extraction system is used for the experiment. Bias voltage between a discharge chamber and a positive (plasma) electrode is applied for sheath potential control. Two types of electrode systems have been examined, such as straight hole aperture (S type) and recessed hole aperture (R type), and have found that the effects of the bias voltage on the beam characteristics depend on the type of aperture and the deceleration voltage. For an S-type system, the application of bias voltage improves the beam performance in a Iow deceleration voltage (-600 V), but not in a high deceleration voltage (- 1600 V). For an R-type system, almost no improvement is observed in all deceleration voltages. Although the highest brightness is obtained in a deceleration voltage of -1600 V without the application of bias voltage in the S-type system, the significant fraction of the intersecting beam to the electrodes is present in this case. [ABSTRACT FROM AUTHOR]

The measurements of spatial profiles of primary electron (high-energy tail electron) density in a magnetic multicusp ion source have been made in the cases of different current directions of ‘‘T’’-shaped filaments, and its effects on the beam extraction have been studied. The axial profiles of arc plasma parameters in the ion source were measured by use of a movable Langmuir probe. A high-energy tail electron density ntail is calculated from the electron energy distribution function derived from probe current-voltage characteristics using Druyvesteyn’s method. It is confirmed that the axial profiles of tail electron density ntail relates to the location of primary electron emission. The results indicate that higher ion-beam current is observed in the case that ntail and equivalent electron temperature Tequ are higher near the plasma electrode. [ABSTRACT FROM AUTHOR]

This paper describes an automatic text- and speaker- independent language identification method based on bidden Markov models (HMMs) for acoustic features. The bidden Markov modeling is used to represent the phonotactics for each language. Each language has its proper phonotactics. The HMM topology here is a fully structured (ergodic) model wherein any state could transit to all states. Two kinds of HMMs are used: the discrete HMM (DHMM) with the code book and the continuous density HMM (CHMM). The HMM was trained using both the Bam-Welch (forward-backward) algorithm and the Viterbi algorithm. The latter was used for emphasizing the state transition probability. For comparison, experiments also were conducted on the identification using a mixtured Gaussian distribution model with one state. This single-state Gaussian distribution model gave the same performance as the HMM trained with the Baum-Welch algorithm. This is because the transition between states which reflects the characteristics of each language does not affect the likelihood scores very much. This problem was addressed by emphasizing the transition probabilities and using the Viterbi algorithm, which resulted in an improvement in the recognition rates. The trigram for optimal state sequence is introduced. Combining it with the HMM produced the best results. [ABSTRACT FROM AUTHOR]

Studies the effects of the ambient gas in the ion drift space on the transport property of the low energy and high brightness beam. Use of a bucket ion source with single-aperture triode extraction; Improvements in beam characteristics; Electron density in the ion-beam plasma.

This study investigated the influence of periosteal tissue of different origins on the calcification at the diaphysis and chondrocyte maturation at the epiphysis in an engineered phalanx. We hypothesized that the periosteum from long bones would better provide donor cells for bone formation and signals for maturation of the joint cartilage. Periosteum was harvested from 4 locations (cranium, mandible, radius, and ilium) of calf bones. A human phalangeal bone-shaped, biodegradable, 3-dimensional scaffold hydroxyapatite-poly L-lactic-ɛ-caprolactone (HA-P[LA/CL]) was prepared using a human phalangeal bone-shaped template. A bioengineered human phalanx was fabricated by combining periosteal grafts with biodegradable copolymers. The joint cartilage region (chondrocyte/polyglycolic acid [PGA] composite) was subsequently sutured to the phalangeal bone region (periosteum/HA-P[LA/CL] composite) with absorbable sutures to make a human phalangeal bone model. These were then implanted in nude mice for maturation of the constructs. Macroscopic, radiographic, histological, and immune-histochemical evaluations were carried out to determine the relative influence of the periosteal graft source on bone and cartilage formation at 10 and 20 weeks after implantation. Calcification localized under the periosteum was noted in the cranium, radius, and ilium groups after 10 weeks, which markedly expanded at the modelled diaphysis after 20 weeks. The width in the minor axis direction tended to increase with time after grafting in the cranium group, whereas the longitudinal length increased in the radius and ilium groups. The joint cartilage thickness changed with time depending on the type of periosteum, and periosteum collected from the radius and ilium was associated with the greatest cartilage thickness in the joint cartilage maturation process. These results suggest that periosteum collected from radius of calves demonstrated superior bone formation and chondrocyte maturation in the engineered phalanx compared with other sources of periosteum. The osteogenic capacity depends on the periosteal source regardless of intramembranous or endochondral ossification. The appropriate periosteal choice is essential in the phalangeal bone and cartilage tissue engineering. The results are important for broadening tissue engineering possibilities for clinical application. [ABSTRACT FROM AUTHOR]

Investigates the causes of energy spread of the very low energy and high perveance ion beams. Energy distribution of the ion beam; Effect of plasma potential on voltage acceleration; Effects the neutralization of the space charge.