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Background: Artificial intelligence (AI) is changing our life, including the medical field. Repeated machine learning using big data made various fields more predictable and accurate. In medicine, IBM Watson for Oncology (WFO), trained by Memorial Slone Kettering Cancer Center (MSKCC), was first introduced and applied in 14 countries worldwide.Our study was designed to assess the feasibility of WFO in actual clinical practice. We aimed to investigate the concordance rate between WFO and multidisciplinary tumor board (MTB) in Urologic cancer patients. Materials and methods: We reviewed retrospectively collected data for consecutive patients who underwent WFO and MTB simultaneously in the diagnosis of urologic malignancy before determining further treatment between August 2017 and September 2020. We compared the recommendation of the AI system, WFO (IBM Watson Health, Cambridge, MA), with the opinion of MTB for further managing all patients diagnosed with urologic malignancies such as prostate, bladder, and kidney cancer. Results: A total of 55 patients were enrolled in our study. The number of patients with prostate cancer was 48. The number of bladder and kidney cancer patients was 5 and 2, respectively. The overall concordance rate between WFO and MTB was 92.7%. Three patients could not suggest proper treatment options using WFO, and the recommended choice of WFO was not feasible in the Korean Health Insurance Review and Assessment Service. Conclusions: The decision of WFO showed a high concordance rate with a multidisciplinary tumor board for urologic oncology. However, some recommendations of WFO were not feasible in actual practice, and WFO still has some points to improve and modify. Interestingly, applying WFO is likely to facilitate a multidisciplinary team approach.

Objectives: When air irrigation is used for caloric stimulation in patients with a perforated ear, warm irrigation may elicit a nystagmus that initially beats in the opposite direction of what is expected for warm irrigations, which is referred to as “caloric inversion”. This study aimed to investigate the disease group in which caloric inversion appeared in patients who underwent caloric testing and to classify the patterns of caloric inversion. Methods: We conducted a retrospective review of bithermal caloric test results that were collected in our dizziness clinic between 2005 and 2022. Caloric inversion was defined when nystagmus induced by caloric stimulation appeared in the opposite direction to that expected. The incidence of caloric inversion among all patients who underwent bithermal caloric tests was calculated. To confirm the clinical diagnoses of the patients with caloric inversion, their clinical records were reviewed. Results: Out of 9923 patients who underwent bithermal caloric tests, 29 patients (0.29%) showed a caloric inversion. The most common clinical diagnosis was chronic otitis media (21 of 29, 72%). Of the 21 patients with chronic otitis media, 20 patients showed a caloric inversion by warm air irrigation and one patient showed caloric inversion by cold air stimulation. Patients with clinical diagnoses other than chronic otitis media such as sudden sensorineural hearing loss, benign paroxysmal vertigo of childhood and recurrent vestibulopathy showed caloric inversion by warm air irrigation. Caloric inversion by warm water irrigation was observed in patients with lateral semicircular canal cupulopathy and recurrent vestibulopathy. Two patients (one with Meniere’s disease and one with age-related dizziness) showed caloric inversion by cold water irrigation. Conclusion: Caloric inversion can be observed in various diseases other than chronic otitis media with tympanic membrane perforation. Special care should be taken in the interpretation of caloric test results. Level of Evidence: Level 4.

Korean Red Ginseng (KRG) plays a key role in heme oxygenase (HO)-1 induction under physical and moderate oxidative stress conditions. The transient and mild induction of HO-1 is beneficial for cell protection, mitochondrial function, regeneration, and intercellular communication. However, chronic HO-1 overexpression is detrimental in severely injured regions. Thus, in a chronic pathological state, diminishing HO-1-mediated ferroptosis is beneficial for a therapeutic approach. The molecular mechanisms by which KRG protects various cell types in the central nervous system have not yet been established, especially in terms of HO-1-mediated mitochondrial functions. Therefore, in this review, we discuss the multiple roles of KRG in the regulation of astrocytic HO-1 under pathophysiological conditions. More specifically, we discuss the role of the KRG-mediated astrocytic HO-1 pathway in regulating mitochondrial functions in acute and chronic neurodegenerative diseases as well as physiological conditions.

Abstract Objective To investigate the characteristics of positional nystagmus in posterior semicircular canal (PSCC) benign paroxysmal positional vertigo (BPPV) patients with longer durations, and to discuss the possible underlying mechanism of this nystagmus. Methods We conducted a retrospective review, and enrolled 118 consecutive patients with unilateral PSCC BPPV. The duration of nystagmus during a Dix‐Hallpike test was classified into short (

Vestibular schwannoma (VS) is commonly accompanied by hearing loss, tinnitus, and dizziness and tends to be chronically progressive in nature. We report a case of VS presenting as left vestibular neuritis (VN) in a previously healthy 57-year-old patient. Right-beating horizontal-torsional spontaneous nystagmus was observed, and the bedside head impulse test revealed a left catch-up saccade. The bithermal caloric test showed left canal paresis, and pure-tone audiometry revealed an average threshold of 22.5 dB bilaterally. Brain magnetic resonance imaging (MRI) demonstrated a 0.7-cm enhancing mass in the left internal auditory canal, consistent with VS. The patient was administered with high-dose systemic corticosteroids and vestibular suppressants with antiemetic, which relieved acute vertigo. Although dizziness in VS is chronically progressive in nature, VS may present as an acute vestibular syndrome that mimics VN. VS should be considered a potential cause of acute vestibular syndrome, and thorough neurological examination with MRI may be helpful for accurate diagnosis.

Direction-changing positional nystagmus (DCPN), which refers to the change in the direction of nystagmus with different head positions, is a well-known characteristic of horizontal semicircular canal BPPV. The supine head roll test is commonly used to diagnose horizontal canal BPPV. However, persistent geotropic DCPN observed during this test cannot be explained by the conventional explanations of canalolithiasis or cupulolithiasis. To account for this unique nystagmus, the concept of a “light cupula” has been recently introduced. In this review, we provide an overview of the historical background, clinical features and diagnostic methods, proposed mechanisms, and treatment strategies associated with the light cupula phenomenon based on the available literature to date.

Abstract Objective To examine the treatment effects of repositioning maneuvers with the head turned 45° downwards (Gufoni maneuver) and 45° upwards (Appiani maneuver) in 25 patients with ageotropic horizontal semicircular canal (HSCC) benign paroxysmal positional vertigo (BPPV). Methods Patients were randomly assigned to the Gufoni or Appiani maneuvers, and their immediate and short‐term efficacy was investigated. Results The immediate treatment response was successful in four of 16 patients who were treated with the Appiani maneuver and were not successful in any of the nine patients treated with the Gufoni maneuver. The patients who showed spontaneous resolution during follow‐up outnumbered the patients who showed resolution of ageotropic HSCC BPPV immediately after the repositioning maneuvers. Conclusion This study showed a very low immediate resolution rate of ageotropic HSCC BPPV after the Gufoni maneuver; this may be attributed to the less effectiveness of the Gufoni maneuver against debris that often exists in the canal side of the cupula. Another interesting finding was that the rate of spontaneous resolution during the follow‐up period was higher than that of immediate resolution after the repositioning maneuvers, which may support the recently proposed hypothesis that ageotropic positional nystagmus can also be evoked by causes other than the otolithic attachment on the cupula, such as a slight change in the biochemical composition of the inner ear fluids. Level of Evidence 3.

Astrocytes play a key role in brain functioning by providing energy to neurons. Increased astrocytic mitochondrial functions by Korean red ginseng extract (KRGE) have been investigated in previous studies. KRGE administration induces hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in astrocytes in the adult mouse brain cortex. VEGF expression can be controlled by transcription factors, such as the HIF-1α and estrogen-related receptor α (ERRα). However, the expression of ERRα is unchanged by KRGE in astrocytes of the mouse brain cortex. Instead, sirtuin 3 (SIRT3) expression is induced by KRGE in astrocytes. SIRT3 is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that resides in the mitochondria and maintains mitochondrial homeostasis. Mitochondrial maintenance requires oxygen, and active mitochondria enhance oxygen consumption, resulting in hypoxia. The effects of SIRT3 on HIF-1α-mediated mitochondria functions induced by KRGE are not well established. We aimed to investigate the relationship between SIRT3 and HIF-1α in KRGE-treated normoxic astrocyte cells. Without changing the expression of the ERRα, small interfering ribonucleic acid targeted for SIRT3 in astrocytes substantially lowers the amount of KRGE-induced HIF-1α proteins. Reduced proline hydroxylase 2 (PHD2) expression restores HIF-1α protein levels in SIRT3-depleted astrocytes in normoxic cells treated with KRGE. The translocation of outer mitochondrial membranes 22 (Tom22) and Tom20 is controlled by the SIRT3-HIF-1α axis, which is activated by KRGE. KRGE-induced Tom22 increased oxygen consumption and mitochondrial membrane potential, as well as HIF-1α stability through PHD2. Taken together, in normoxic astrocytes, KRGE-induced SIRT3 activated the Tom22–HIF-1α circuit by increasing oxygen consumption in an ERRα-independent manner.

There have been no reports regarding nystagmus observed immediately after the end of an acute vertiginous attack in patients with Meniere’s disease. The aim of this study was to demonstrate positional direction-changing nystagmus in patients with Meniere’s disease, and to discuss the mechanism that underlies this nystagmus. Video-nystagmography was recorded in two patients with definite Meniere’s disease, who showed positional direction-changing nystagmus during the period immediately after a vertigo attack. In one patient, video-nystagmographic recording was conducted 5 h after an episode of vertigo attack, and it showed very weak, persistent positional geotropic direction-changing nystagmus. In the other patient, video-nystagmographic recording was conducted 23 h after an episode of vertigo attack, and it showed very weak, persistent positional apogeotropic direction-changing nystagmus. Our patients exhibited very weak, persistent positional direction-changing nystagmus, which was geotropic in one and apogeotropic in the other. This type of positional nystagmus has been reported in other inner ear disorders and it cannot be clearly explained by typical benign paroxysmal positional vertigo. The change in chemical composition and/or electrolyte concentration of the inner ear fluid, although still unclear, may underlie the production of this characteristic nystagmus in these patients.

Abstract This study aimed to investigate the incidence of mastoid effusion on temporal bone magnetic resonance imaging (MRI) in patients with Bell’s palsy (BP) and Ramsay Hunt syndrome (RHS), and evaluate the usefulness of mastoid effusion in early differential diagnosis between BP and RHS. The incidence of mastoid effusion on 3.0 T—temporal bone MRI, which was conducted within 10 days after the onset of acute facial nerve palsy, was compared between 131 patients with BP and 33 patients with RHS. Findings of mastoid cavity on temporal bone MRI were classified into three groups as normal mastoid, mastoid effusion, and sclerotic change, and the incidence of ipsilesional mastoid effusion was significantly higher in RHS than BP (P

Alkaline water electrolysis (AWE) is a mature water electrolysis technology that can produce green hydrogen most economically. This is mainly attributed to the use of Ni-based materials that are easy to process and inexpensive. The nickel-based meshes with various structures such as woven mesh and expanded mesh are widely used as electrode in the AWE due to its common availability and easy fabrication. However, the morphological effect of meshes on hydrogen evolution reaction (HER) performance has not been studied. Here a new parameter to determine the structural effect of mesh on HER performance was first proposed. The key factors of the parameter were found to be the strand width, pore width and the strand surface area. The woven mesh with the ratio of pore width to strand width that converges to 1 showed the lowest the overpotential. The expanded mesh with the higher the structural surface area exhibited the lowest the overpotential. This study will help to choose an optimal structure for the mesh with the HER electrode.

Herpes zoster oticus (HZO) is characterized by otalgia and erythematous vesicles in the auricle or external auditory canal. Ramsay Hunt syndrome (RHS) can be diagnosed when facial nerve palsy is accompanied by these symptoms of HZO, and in this case, audio-vestibular symptoms such as hearing loss or dizziness often develop. Recently, 3D-fluid-attenuated inversion recovery sequence (3D-FLAIR) magnetic resonance imaging (MRI) has been introduced in order to evaluate the inner ear structure pathology. The purpose of this study was to investigate the audio-vestibular characteristics in correlation with temporal bone MRI findings in HZO patients. From September 2018 to June 2022, 18 patients with HZO participated in the study. Thirteen patients (77%) showed high-signal intensity in the inner ear structures in 4 h post-contrast 3D-FLAIR images. In a bithermal caloric test, the lateral semicircular canal showed high signal intensity in 4 h post-contrast 3D-FLAIR images in 75% of patients with abnormal canal paresis. While the cochlea showed high signal intensity in 4 h post-contrast 3D-FLAIR images in 75% of patients with hearing loss, the vestibulo-cochlear nerve showed enhancement in post-contrast T1-weighted images in only 33% of patients with hearing loss. The present study demonstrates that audio-vestibular deficits are well-correlated with increased signal intensity of the inner ear endorgans in 4 h post contrast 3D-FLAIR MRI.

A photovoltaic–electrolysis–PEM hybrid model was developed for a feasibility study, and simulations of several scenarios in Korea were performed. The solar irradiance was derived from the University of Arizona solar irradiance based on satellite–Korea Institute of Energy Research model which provides the satellite imagery over the Korean peninsula every 15 min. In Korea, the annual average solar irradiance is 1,310 kWh m−2 with a maximum of 1,440 kWh m−2 in 2017. Electricity load and solar irradiance information were used to test the performance model of the photovoltaic–electrolysis–PEM hybrid system for baseload and several peak load shave runs. When the baseload was set at 4200 MW, the total capacity of the Photovoltaic plants was 58.5 GWp. In contrast, the hybrid system reduced the peak load more efficiently during daytime. In particular, the capacity factor of the Proton Exchange Membrane system increased in winter because the solar irradiance is relatively weak in that season. These results provide useful insights for the development of control logic models for the PV–electrolysis–PEM system in micro-grid setups.

Abstract Because the density of air is lower than the effusion, air bubbles can be passively moved by a head position change, causing a bubbling sound in the affected ear.

The beneficial effects of Korean red ginseng extract (KRGE) on the central nervous system (CNS) have been reported. Among the CNS cells, astrocytes possess robust antioxidative properties and regenerative potential. Under physiological conditions, biliverdin reductase A (BVR-A) converts biliverdin (a heme oxygenase metabolite) into bilirubin, a major natural and potent antioxidant. We found that KRGE enhanced BVR-A in astrocytes in the fimbria region of the adult mouse hippocampus under physiological conditions. KRGE-induced BVR-A expression and subsequent bilirubin production were required for changes in mitochondrial membrane potential, mitochondrial mass, and oxidative phosphorylation through liver kinase B1 (LKB1), estrogen-related receptor α (ERRα), and sirtuin (SIRT1 and SIRT5) in astrocytes. However, BVR-A did not affect the KRGE-induced expression of AMP-activated protein kinase α (AMPKα). The KRGE-stimulated BVR-A–LKB1–SIRT1–ERRα pathway regulates the levels of mitochondria-localized proteins such as SIRT5, translocase of the outer mitochondrial membrane 20 (Tom20), Tom22, cytochrome c (Cyt c), and superoxide dismutase 2 (SOD2). Increased Tom20 expression in astrocytes of the hippocampal fimbria region was observed in KRGE-treated mice. KRGE-induced expression of Cyt c and SOD2 was associated with the Tom20/Tom22 complex. Taken together, KRGE-induced bilirubin production is required for enhanced astrocytic mitochondrial function in an LKB1-dependent and AMPKα-independent manner under physiological conditions.

Background: There are debates on whether mastoid oscillation has any benefit or harm in treating horizontal semicircular canal (HSCC) cupulolithiasis. The goal of this study was to investigate the therapeutic effects of the new maneuver using only inertia and gravity and compare it with the previously reported cupulolith repositioning maneuver using mastoid vibration (CuRM). Methods: We enrolled 57 patients diagnosed with HSCC cupulolithiasis. Patients were randomly allocated to the previously reported CuRM or the new maneuver (briefly, 30° head rotation to the affected side and thereafter bidirectional side-lying) using simply inertia and gravity, and their immediate and short-term effects were evaluated. Results: The immediate success rate did not differ significantly between the CuRM (8 of 22, 36.4%) and the new maneuver (10 of 35, 28.6%) groups (p = 0.538, Pearson’s chi-square test). The late resolution rates at the first follow-up of the CuRM (75%, 9 of 12) and new maneuver groups (82.6%, 19 of 23) were very high, and there was no statistical difference between them (p = 0.670, Fisher’s exact test). Conclusions: This study showed that the new maneuver was effective for treating HSCC cupulolithiasis with an immediate success rate of 28.6% (10 of 35). Although it did not show better results than the existing maneuver using vibration, there was no statistical difference. Considering the debate on the effectiveness of oscillation, we believe our new maneuver is a conservative alternative that uses only inertia and gravity, and it can be easily performed in clinics where oscillation equipment is not available.

Background: Although the occurrence of optokinetic reflex (OKR) adaptation after OKR training is well established, the dynamic properties of OKR adaptation has not been fully studied. This study aimed to examine the difference in the amount of OKR adaptation according to OKR training protocols which have different frequency or amplitude of drum oscillation. Methods: Using C57BL/6N male mice, we induced OKR adaptation by 3 different categories of learning paradigm as follows: (1) Optokinetic drum oscillation for 60 min with same amplitude and different frequency. (2) Optokinetic drum oscillation for 60 min with same frequency and different amplitude. (3) Training with serial combination of different frequency or amplitude. Results: The results show that the amount of OKR adaptation was greater after OKR training with lower frequency or amplitude than that with higher frequency or amplitude. Conclusions: This finding may suggest that the retinal slip signal with lower-velocity OKR stimulation serves as more precise instructive signal for learning, leading to induction of more efficient training effect. Another interesting finding was that the OKR gain increase tended to be greater after training composed of sequential combination of decreasing frequency or amplitude than that composed of sequential combination of increasing frequency or amplitude. Furthermore, the OKR training with high frequency or amplitude eliminated a part of learning effects which have already formed by previous training. We postulate that the stimulation during training with high frequency or amplitude may implement a disturbing instruction for OKR learning when it is conducted in mice with increased OKR gain after previous OKR training.

A 75-year-old patient complained of mastication-induced clicking tinnitus on the left side, and otoendoscopic examination revealed that the left tympanic membraneTM was outwardly bulged by clenching her teeth. Temporal bone computed tomography demonstrated that the posteromedial bony wall of the glenoid was partially dehiscent, allowing herniation of soft tissue contents of temporomandibular joint into the middle ear. Increased middle ear pressure due to soft tissue herniation can induce left tympanic membrane bulging and accompanying clicking tinnitus. Herniation of temporomandibular joint soft tissue into the middle ear should be considered as a differential diagnosis when clicking tinnitus is evoked by mastication. Keywords: Tinnitus, Mastication, Temporomandibular joint, Middle ear, Foramen of Huschke

Objectives Direction-changing positional nystagmus (PN) was considered to indicate the presence of benign paroxysmal positional vertigo involving lateral semicircular canal in most cases. We investigated the incidence of PN on the supine head-roll test and compared the characteristics of nystagmus in patients with vestibular neuritis (VN) and Meniere disease (MD). Methods A retrospective review of patients, who were diagnosed with unilateral VN or unilateral definite MD between September 2005 and November 2011, was conducted. Sixty-five VN patients and 65 MD patients were enrolled. Eye movements were recorded for 30–60 seconds at the positions of sitting, head roll to the right, and head roll to the left, and maximum slow-phase eye velocity was calculated. PN was classified as direction-fixed (paretic or recovery) and direction-changing (geotropic or apogeotropic). Results Spontaneous nystagmus was observed in 57 patients (87%, the slow-phase eye velocity of 7°/sec±5°/sec) with acute VN, 39 (60%, 2°/sec±1°/sec) with follow-up VN, and 32 (49%, 2°/sec±2°/sec) with MD. Direction-fixed PN was the most common type. Direction-fixed paretic type was most common in acute VN (80%) and follow-up VN (42%), and direction-fixed recovery type was most common in MD (31%). Paretic type was significantly more common in acute VN (80%) than in follow-up VN (42%) and MD (26%), and the recovery type was significantly more common in MD (31%) than in acute VN (3%) and follow-up VN (14%). Direction-changing PN was more common in MD (22%), followed by follow-up VN (14%) and acute VN (9%). Conclusion Though direction-fixed paretic PN was most common in VN and MD patients, direction-changing PN could be observed in a few patients (9%–20%) with peripheral vestibular disorders regardless of the duration from the onset of dizziness, suggesting the presence of otolith-related dizziness.

Abstract Background Hemotympanum refers to both the presence of blood in the middle ear cavity and to ecchymosis of the tympanic membrane (TM), and a systematic study of intra-TM (iTM) hemorrhage without bleeding in the middle ear cavity has not been conducted. The goals of our study were to analyze the causes of iTM hemorrhage without TM perforation or bleeding in the middle ear cavity, and to demonstrate the clinical characteristics of the disease. Methods This Case series study included five patients with iTM hemorrhage between August 2014 and August 2017. An iTM hemorrhage was diagnosed when otoendoscopic examination demonstrated minor bleeding behind the intact TM, a hemorrhage was observed between the TM annulus and the epidermal layer, and temporal bone computed tomography revealed thickening of the TM without soft tissue density within the tympanic cavity or temporal bone fracture. Initial symptoms, and serial findings of otoendoscopy and pure tone audiometry (PTA) were investigated. Results iTM hemorrhage developed due to blunt head trauma in two patients, descent barotrauma during scuba diving in two patients, and spontaneous epistaxis in one patient. Otalgia and ear fullness were the most common symptoms, but PTA showed no or minimal conductive hearing loss in all patients. Conclusions An iTM hemorrhage may develop after blunt head trauma, barotrauma due to scuba diving, or spontaneous epistaxis; otological symptoms included otalgia, tinnitus, and aural fullness. An iTM hemorrhage resolved spontaneously without specific treatment, usually within 1 month.

Abstract Introduction The superiority of spaced training, in which repeated training sessions are given with resting intervals, over massed training in learning efficacy has been well established. However, longer duration of total training time has been required for spaced training than massed training because spacing intervals intervene between training sessions in spaced training. Thus, the learning efficacy may not be simply compared between spaced and massed training in terms of “time efficiency.” The aim of the present study was to investigate the efficacy of spaced and massed training using adaptation of horizontal optokinetic reflex (hOKR) in mice. Methods Training paradigms were categorized into seven groups according to the duration of spacing interval, keeping total duration of hOKR training including spacing almost equal in all training paradigms. Results The amount of short‐term hOKR gain increase immediately after the 60 min hOKR training was not significantly different among seven training paradigms. The hOKR adaptation was still in progress during a spacing interval, and the increment in hOKR gain tended to be greater with the longer spacing interval. The increase in hOKR gain was maintained until 48 hr after the end of training in both massed and spaced training. Conclusion The short‐term learning effect was not significantly different among training paradigms regardless of spacing interval in hOKR adaptation, which suggests that the spacing effect is robust enough to overcome the shortage of optokinetic training cycles in hOKR adaptation.

The present study aimed to investigate the incidence and patterns of nystagmus in adult patients with acute otitis media (AOM) or otitis media with effusion (OME) without dizziness or vertigo, and discuss possible mechanisms. From February 2018 to November 2018, 34 consecutive patients with AOM or OME without dizziness were included. Nystagmus was examined with video Frenzel glasses. Of 34 adult AOM or OME patients without dizziness, nystagmus was observed in 28 patients (82%). In unilateral AOM or OME (n = 30), the most commonly observed nystagmus pattern was irritative-type direction-fixed nystagmus (n = 13), followed by paretic-type direction-fixed nystagmus (n = 8), and direction-changing positional nystagmus (n = 4). In bilateral AOM or OME (n = 4), direction-fixed nystagmus and direction-changing positional nystagmus were observed in two and one patients, respectively. Nystagmus was observed in as many as 82% of adult AOM or OME patients even though they did not complain of dizziness, and the pattern of nystagmus was either direction-fixed or direction-changing. Direct effect of inflammatory mediators penetrated from the middle ear and biochemical alteration in the inner ear fluids due to blood-perilymph barrier dysfunction may result in the presence of nystagmus in AOM or OME patients without dizziness.

Ceruminous glands are located in the skin of the cartilaginous portion of the external auditory canal, and ceruminous gland adenoma originating from the middle ear mucosa is extremely rare. We report a case of middle ear ceruminous gland adenoma which caused long-standing otomastoiditis and mixed hearing loss with a large air-bone gap by obstructing the bony Eustachian tube. We discuss the clinical characteristics and histologic features of the present case.

Reducing the iridium loading for the oxygen evolution reaction (OER) is one of the main challenges of polymer electrolyte membrane water electrolysis (PEMWE). This study introduces grape-like iridium nanoclusters supported on boron carbide (B4C) which increase iridium utilization compared to a non-supported iridium catalyst. A simple chemical reduction method with NaBH4 as a reducing agent was used to synthesize iridium nanoclusters on B4C. TEM images indicated that grape-like iridium nanoclusters were successfully dispersed on the B4C support. The catalytic performance of Ir/B4C was better than that of a commercial catalyst. To reach a current density of 10 mA/cm2, the overpotential of Ir/B4C was less than that of the commercial catalyst by 32 mV. Ir/B4C also has a mass activity 2.55 times higher than that of the commercial catalyst at 1.55 V. These improvements are attributed to the high electrochemical active surface area, the weak adsorption strength of oxygen, and the presence of Ir(OH)4 on the surface. The durability of Ir/B4C is comparable to that of the commercial catalyst at 1 mA/cm2 for 15 h and higher at 10 mA/cm2 for 3 h. B4C may weaken the oxidative dissolution of iridium by transferring electrons even though the high electrochemical surface area of iridium in Ir/B4C may reduce its durability.

In terms of diagnosis, a painless isolated mass lesion around the mastoid area is rarely encountered in general practice. In the present study, we report two cases of painless benign mastoid tumors located in the postauricular region. The first patient visited our department with a painless progressing mass lesion behind the right ear, which was later revealed as an intramuscular lipoma in the mastoid origin site of the sternocleidomastoid muscle. The second patient similarly presented to our department with a chief complaint of a painless, palpable mass in the mastoid region. Biopsy results confirmed the diagnosis of an osteoma. In both cases, the tumor was surgically removed by a postauricular approach. Although osteoma and lipoma are benign tumors rarely involved in the mastoid area, presenting without symptoms, it is recommended of complete excision, especially in cases with symptoms or cosmetic deformity.

The intermittent and volatile nature of renewable energy sources threatens the stable operation of power grids, necessitating dynamically operated energy storage. Power-to-gas technology is a promising method for managing electricity variations on a large gigawatt (GW) scale. The electrolyzer is a key component that can convert excess electricity into hydrogen with high flexibility. Recently, organic/inorganic composite separators have been widely used as diaphragm membranes; however, they are prone to increase ohmic resistance and gas crossover, which inhibit electrolyzer efficiency. Here, we show that the ceria nanoparticle and polysulfone composite separator exhibits a low area resistance of 0.16 Ω cm2 and a hydrogen permeability of 1.2 × 10–12 mol cm–1 s–1 bar–1 in 30 wt% potassium hydroxide (KOH) electrolyte, which outperformed the commercial separator, the Zirfon PERL separator. The cell using a 100 nm ceria nanoparticle/polysulfone separator and advanced catalysts has a remarkable capability of 1.84 V at 800 mA cm−2 at 30 wt% and 80 °C. The decrease in the average pore size of 77 nm and high wettability (contact angle 75°) contributed to the reduced ohmic resistance and low gas crossover. These results demonstrate that the use of ceria nanoparticle-based separators can achieve high performance compared to commercial zirconia-based separators.

This study aimed to develop a deeper understanding of contemporary aspects of meritocracy based on a qualitative meta-synthesis of the scholarly literature. Eighteen empirical studies of meritocracy in various disciplines were reviewed for this study. Thematic analysis revealed three main higher-order themes with six sub-themes that described the characteristics of meritocracy today. The findings present an overview of the current issues considered by meritocracy studies and provide a foundation for the ongoing debate over the necessary conditions for a better meritocracy.

Purpose Prenatal environmental conditions affect the development of the fetus. In the present study, we investigated the effects of exposure to music and noise during pregnancy on neurogenesis and thickness in the motor and somatosensory cortex of rat pups. Methods The pregnant rats in the music-applied group were exposed to 65 dB of comfortable music for 1 hour, once per day, from the 15th day of pregnancy until delivery. The pregnant rats in the noise-applied group were exposed to 95 dB of sound from a supersonic sound machine for 1 hour, once per day, from the 15th day of pregnancy until delivery. After birth, the offspring were left undisturbed together with their mother. The rat pups were sacrificed at 21 days after birth. Results Exposure to music during pregnancy increased neurogenesis in the motor and somatosensory cortex of rat pups. In contrast, rat pups exposed to noise during pregnancy showed decreased neurogenesis and thickness in the motor and somatosensory cortex. Conclusions Our study suggests that music and noise during the developmental period are important factors influencing brain development and urogenital disorders.