Pros and cons of a bone-conduction device implanted in the worse hearing ear of patients with asymmetric hearing loss

PurposeBone-conduction devices can be considered a viable treatment option for patients experiencing asymmetric hearing loss (AHL), especially those with severe to profound hearing loss (HL) present in one ear. However, there are only a few reports on the effects of bone-anchored hearing aids (BAHAs) on patients with AHL. This retrospective study analyzed in detail the effects of BAHA on softer sounds than other hearing aids and identified situations in which BAHA had a negative effect.MethodsPatients with AHL, characterized by severe to profound hearing loss in one ear with a difference of ≥45 dB from that of the contralateral ear, underwent BAHA implantation in the ear with worse hearing. The BAHA effects were evaluated by assessing the word recognition score (WRS) and speech reception threshold (SRT) using the Japanese Oldenburg Sentence Test for various signal settings and noise directions. For a subjective analysis, the Speech, Spatial and Qualities of Hearing Scale (SSQ12) score was determined.ResultsThirteen patients who underwent BAHA implantation at the Miyazaki University Hospital between 2007 and 2021 were included. The BAHA demonstrated a significant improvement in the WRS from 40 to 70 dB sound pressure levels. Although the SRT showed significant improvement in noisy environments when speech was presented to the BAHA-wearing side, it worsened significantly when noise was presented to this side. In the survey of subjective hearing ability, both the total and subscale SSQ12 scores improved significantly after wearing the BAHA.ConclusionThis study identified scenarios in which BAHAs were beneficial and detrimental to individuals with AHL. Generally used audiological tests, such as the WRS with fixed sound pressure, may underestimate the effectiveness of BAHAs for softer sounds. In addition, depending on the direction of the noise, BAHAs may have adverse effects. These results could help patients comprehend the potential benefits and limitations of bone-conduction devices for their hearing

Development of speckle-free channel-cut crystal optics using plasma chemical vaporization machining for coherent x-ray applications

We have developed a method of fabricating speckle-free channel-cut crystal optics with plasma chemical vaporization machining, an etching method using atmospheric-pressure plasma, for coherent X-ray applications. We investigated the etching characteristics to silicon crystals and achieved a small surface roughness of less than 1 nm rms at a removal depth of >10 μm, which satisfies the requirements for eliminating subsurface damage while suppressing diffuse scattering from rough surfaces. We applied this method for fabricating channel-cut Si(220) crystals for a hard X-ray split-and-delay optical system and confirmed that the crystals provided speckle-free reflection profiles under coherent X-ray illumination.Takashi Hirano, Taito Osaka, Yasuhisa Sano, Yuichi Inubushi, Satoshi Matsuyama, Kensuke Tono, Tetsuya Ishikawa, Makina Yabashi, and Kazuto Yamauchi, "Development of speckle-free channel-cut crystal optics using plasma chemical vaporization machining for coherent x-ray applications", Review of Scientific Instruments 87, 063118 (2016) https://doi.org/10.1063/1.4954731

Thin crystal development and applications for hard x-ray free-electron lasers

Taito Osaka, Makina Yabashi, Yasuhisa Sano, Kensuke Tono, Yuichi Inubushi, Takahiro Sato, Kanade Ogawa, Satoshi Matsuyama, Tetsuya Ishikawa, and Kazuto Yamauchi "Thin crystal development and applications for hard x-ray free-electron lasers", Proc. SPIE 8848, Advances in X-Ray/EUV Optics and Components VIII, 884804 (27 September 2013); https://doi.org/10.1117/12.2023465

Mucin Production and Mucous Cell Metaplasia in Otitis Media

Otitis media (OM) with mucoid effusion, characterized by mucous cell metaplasia/hyperplasia in the middle ear cleft and thick fluid accumulation in the middle ear cavity, is a subtype of OM which frequently leads to chronic OM in young children. Multiple factors are involved in the developmental process of OM with mucoid effusion, especially disorders of mucin production resulting from middle ear bacterial infection and Eustachian tube dysfunction. In this review, we will focus on several aspects of this disorder by analyzing the cellular and molecular events such as mucin production and mucous cell differentiation in the middle ear mucosa with OM. In addition, infectious agents, mucin production triggers, and relevant signaling pathways will be discussed

Case Report Case Report of Atlantoaxial Rotatory Fixation after Cochlear Implantation

Atlantoaxial rotatory fixation (AARF) is a relatively rare condition and is mainly seen in children. We report of a 7-year-old girl suffering from AARF after cochlear implantation (CI). Fortunately, early diagnosis based on three-dimensional computed tomography (3DCT) was made, and the patient was cured with conservative therapy. Nontraumatic AARF, which is also known as Grisel's syndrome and occurs subsequent to neck infections or ear, nose, and throat (ENT) surgery, represents only a small fraction of AARF cases. Two factors are mainly thought to contribute to the pathogenesis of the condition estimated, namely, (i) neck immaturity in children and (ii) infiltration by inflammatory mediators around the upper neck joint, easily permitted by the neck vasculature. AARF should be suspected in case of torticollis developing after ENT surgery

Development of split-delay x-ray optics using Si(220) crystals at SACLA

Taito Osaka, Takashi Hirano, Makina Yabashi, Yasuhisa Sano, Kensuke Tono, Yuichi Inubushi, Takahiro Sato, Kanade Ogawa, Satoshi Matsuyama, Tetsuya Ishikawa, and Kazuto Yamauchi "Development of split-delay x-ray optics using Si(220) crystals at SACLA", Proc. SPIE 9210, X-Ray Free-Electron Lasers: Beam Diagnostics, Beamline Instrumentation, and Applications II, 921009 (8 October 2014); https://doi.org/10.1117/12.2060238

Systematic-error-free wavefront measurement using an X-ray single-grating interferometer

In this study, the systematic errors of an X-ray single-grating interferometer based on the Talbot effect were investigated in detail. Non-negligible systematic errors induced by an X-ray camera were identified and a method to eliminate the systematic error was proposed. Systematic-error-free measurements of the wavefront error produced by multilayer focusing mirrors with large numerical apertures were demonstrated at the SPring-8 Angstrom Compact free electron LAser. Consequently, wavefront aberration obtained with two different cameras was found to be consistent with an accuracy better than λ/12.Takato Inoue, Satoshi Matsuyama, Shogo Kawai, Hirokatsu Yumoto, Yuichi Inubushi, Taito Osaka, Ichiro Inoue, Takahisa Koyama, Kensuke Tono, Haruhiko Ohashi, Makina Yabashi, Tetsuya Ishikawa, and Kazuto Yamauchi, "Systematic-error-free wavefront measurement using an X-ray single-grating interferometer", Review of Scientific Instruments 89, 043106 (2018), https://doi.org/10.1063/1.5026440

Single-shot 3D coherent diffractive imaging of core-shell nanoparticles with elemental specificity.

We report 3D coherent diffractive imaging (CDI) of Au/Pd core-shell nanoparticles with 6.1 nm spatial resolution with elemental specificity. We measured single-shot diffraction patterns of the nanoparticles using intense x-ray free electron laser pulses. By exploiting the curvature of the Ewald sphere and the symmetry of the nanoparticle, we reconstructed the 3D electron density of 34 core-shell structures from these diffraction patterns. To extract 3D structural information beyond the diffraction signal, we implemented a super-resolution technique by taking advantage of CDI's quantitative reconstruction capabilities. We used high-resolution model fitting to determine the Au core size and the Pd shell thickness to be 65.0 ± 1.0 nm and 4.0 ± 0.5 nm, respectively. We also identified the 3D elemental distribution inside the nanoparticles with an accuracy of 3%. To further examine the model fitting procedure, we simulated noisy diffraction patterns from a Au/Pd core-shell model and a solid Au model and confirmed the validity of the method. We anticipate this super-resolution CDI method can be generally used for quantitative 3D imaging of symmetrical nanostructures with elemental specificity