Analysis of the association between vestibular schwannoma and hearing status using a newly developed radiomics technique.

PURPOSE: Vestibular schwannoma is a benign tumor originating from Schwann cells surrounding the eighth cranial nerve and can cause hearing loss, tinnitus, balance problems, and facial nerve disorders. Because of the slow growth of the tumor, predicting the hearing function of patients with vestibular schwannoma's is important to obtain information that would be useful for deciding the treatment modality. This study aimed to analyze the association between magnetic resonance imaging features and hearing status using a new radiomics technique. METHODS: We retrospectively analyzed 115 magnetic resonance images and hearing results from 73 patients with vestibular schwannoma. A total of 70 radiomics features from each tumor volume were calculated using T1-weighted magnetic resonance imaging. Radiomics features were classified as histogram-based, shape-based, texture-based, and filter-based. The least absolute shrinkage and selection operator method was used to select the radiomics features among the 70 features that best predicted the hearing test. To ensure the stability of the selected features, the least absolute shrinkage and selection operator method was repeated 10 times. Finally, features set five or more times were selected as radiomics signatures. RESULTS: The radiomics signatures selected using the least absolute shrinkage and selection operator method were: minimum, variance, maximum 3D diameter, size zone variance, log skewness, skewness slope, and kurtosis slope. In random forest, the mean performance was 0.66 (0.63-0.77), and the most important feature was Log skewness. CONCLUSIONS: Newly developed radiomics features are associated with hearing status in patients with vestibular schwannoma and could provide information when deciding the treatment modality.

Audiologic results of total ossicular replacement prosthesis bypassing the stapes suprastructure in canal wall down mastoidectomy.

OBJECTIVES: Sometimes performing PORP adequately is challenging when the stapes is tilted or the suprastructure is partially damaged owing to inflammation or infection. In such cases, the implementation of a TORP bypassing the stapes can be a useful alternative. This study aimed to investigate whether bypassing the stapes suprastructure during total ossicular replacement prosthesis (TORP) affects postoperative complications or audiological outcomes. MATERIAL AND METHODS: Among 104 patients who underwent open cavity mastoidectomy and ossiculoplasty using a titanium prosthesis at Korea University Ansan Hospital between January 2012 and December 2019, we compared the preoperative and postoperative audiological results and surgical complications of 52, 21, and 31 patients who underwent partial ossicular replacement prosthesis (PORP), TORP bypassing the remaining stapes suprastructure, and TORP on the stapes footplate or oval window, respectively. RESULTS: The air-bone gap before surgery was significantly different in the TORP on the stapes footplate group (34.2 ± 12.0 dB) than that in the PORP (22.9 ± 13.8 dB) and TORP bypassing the stapes groups (20.7 ± 11.5 dB, p < 0.001). After surgery, there were no significant differences among the groups (p = 0.818). The air-bone gap difference before surgery was associated with the presence of stapes before surgery (p < 0.001). There was no difference in the proportion of postoperative tympanic perforation, whether it was a revision surgery, malleus status, or the size of perforation of the tympanic membrane among the three groups. CONCLUSION: When performing ossiculoplasty using TORP, bypassing the stapes did not affect surgical and audiologic outcomes.

Analysis of hearing prognosis risk factors in pediatric unilateral sudden sensorineural hearing loss.

OBJECTIVES: Pediatric idiopathic sudden hearing loss (PISSNHL) is a rare disease with no established factor affecting its prognosis. In this study, we investigate the risk factors affecting the prognosis of PISSNHL. MATERIAL AND METHODS: Among the patients who visited our hospital from January 2010 to December 2021, the characteristics associated prognosis of 54 patients with unilateral PISSNHL were retrospectively confirmed. RESULTS: Patients' recovery was determined by applying Siegel's criteria (SC) and AAO-HNS criteria (AC). Twenty-seven (50 %) and 29 patients (54.3 %) recovered for SC and AC, respectively. Age, sex, side, duration between onset and treatment, administration of intra-tympanic steroid injection, accompanying symptoms (tinnitus and dizziness), BMI, serum creatinine level, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte count (PLR), lymphocyte count, and platelet count were not significantly different between the recovery group and the poor recovery group (P > 0.05). The patients were divided into five groups according to the initial hearing of the affected ear and again according to their audiogram type. The initial hearing levels, hearing level severity, and the audiogram type were significantly different between the deaf group (>100 dB HL) and the non-deaf group (P < 0.05). CONCLUSION: The prognosis of PISSNHL is closely related to the initial hearing at the onset. If the initial hearing level is <100 dB, the recovery rate is approximately 50 %, therefore requiring active treatment and emotional support. It may also be related to the type of audiometric curve.

Effect of preparation method of noble metal supported catalyts on formaldehyde oxidation at room temperature: Gas or liquid phase reduction.

Formaldehyde (HCHO) is toxic to the human body and is one of the main threats to the indoor air quality (IAQ). As such, the removal of HCHO is imperative to improving the IAQ, whereby the most useful method to effectively remove HCHO at room temperature is catalytic oxidation. This review discusses catalysts for HCHO room-temperature oxidation, which are categorized according to their preparation methods, i.e., gas-phase reduction and liquid-phase reduction methods. The HCHO oxidation performances, structural features, and reaction mechanisms of the different catalysts are discussed, and directions for future research on catalytic oxidation are reviewed.

Delayed nasoseptal flap reuse in patients with revision endoscopic endonasal anterior skull base surgery.

The reuse of the nasoseptal flap represents a favorable option for skull base reconstruction in revision endoscopic anterior skull base surgery. This study demonstrated that a detached nasoseptal flap can remain viable for several days even if not immediately reattached.

Endoscopic removal of sinonasal hemangioma using vessel sealing device without tumor embolization.

When massive bleeding is anticipated during endoscopic sinonasal tumor removal, a vessel sealing device is useful for successful tumor removal.

Effects of pH and metal composition on selective extraction of calcium from steel slag for Ca(OH)2 production.

This research article explains the effects of pH and metal composition on the selective calcium extraction from steel slag. The operating parameters including extraction solvent type, solvent concentration, metal composition of steel slag, substance type and pH were investigated. HCl, NH4Cl, NH4OH and NaOH were employed as solvents to extract Ca from steel slag. It has been shown that hydrochloric acid effectively extracts Ca. The high metal content in steel slag reacted sensitively to the solvent concentration, and a specific concentration was derived to selectively extract Ca. The optimal solvent for calcium extraction was 2 M HCl, which induced the extraction of 97% of Ca; 46% of Mg; 35% of Al; and 1% of Si from the steel slag. In order to separate Ca in the leaching solution from other metal ions, various acidic/basic substances were added to regulate the pH. The optimal pH level for removing the impurities without calcium was found to be 9.5. The precipitated impurities were removed by filtration, and the pH was adjusted to 13 or higher for Ca(OH)2(s) production. In conclusion, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) revealed that the Ca content produced through the process was more than 99%. It is expected that high-purity Precipitated Calcium Carbonate (PCC) will be achieved when the generated Ca(OH)2 is used as a source of calcium for mineral carbonation.

Role of oxide support in Ni based catalysts for CO2 methanation.

The CO2 methanation reaction of reduced and unreduced Ni based CeO2, Al2O3, TiO2 and Y2O3 supported catalysts was investigated. The Ni/CeO2 and Ni/Y2O3 catalysts exhibited similar CO2 conversions at all reaction temperatures. The catalysts were studied by X-ray diffraction (XRD), H2 chemisorption, H2 temperature-programmed reduction (TPR), and in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS); the results suggested that the reducibility of both metal and support at low temperature, strong metal support interaction and small Ni particle size are important factors for low-temperature CO2 methanation. Based on the DRIFT studies, the difference in the CO2 adsorption properties and reaction pathway depending on the reduced and unreduced Ni based supported catalysts was discussed.

Surface Properties of Cement Kiln Dust with Water Treatment for Selective Extraction of Calcium and Potassium.

Water and hydrochloric acid were employed as solvents to extract K and Ca from K- and Ca- rich cement kiln dust (CKD). It has been shown that hydrochloric acid effectively extracts Ca and K from CKD with efficiencies of more than 85 and 99%, respectively. On the other hand, water, as a solvent, selectively extracts K and Cl with an efficiency of 99%. The selectivity of Ca extracted using hydrochloric acid from treated CKD increased from 37 to 87%. Scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed that K and Cl were dominant on the surface of fresh CKD. After extraction with water, the portion of Ca increased more than twice, and Ca species became dominant. Thus, extraction of CKD with water is capable of selectively removing KCl, leaving Ca on the surface; hence, treated Ca-rich CKD can serve as a suitable raw material for mineral carbonation.