Deafness-associated tRNAPhe mutation impaired mitochondrial and cellular integrity.

Defects in mitochondrial RNA metabolism have been linked to sensorineural deafness that often occurs as a consequence of damaged or deficient inner ear hair cells. In this report, we investigated the molecular mechanism underlying a deafness-associated tRNAPhe 593T > C mutation that changed a highly conserved uracil to cytosine at position 17 of the DHU-loop. The m.593T > C mutation altered tRNAPhe structure and function, including increased melting temperature, resistance to S1 nuclease-mediated digestion, and conformational changes. The aberrant tRNA metabolism impaired mitochondrial translation, which was especially pronounced by decreases in levels of ND1, ND5, CYTB, CO1, and CO3 harboring higher numbers of phenylalanine. These alterations resulted in aberrant assembly, instability, and reduced activities of respiratory chain enzyme complexes I, III, IV, and intact supercomplexes overall. Furthermore, we found that the m.593T > C mutation caused markedly diminished membrane potential, and increased the production of reactive oxygen species in the mutant cell lines carrying the m.593T > C mutation. These mitochondrial dysfunctions led to the mitochondrial dynamic imbalance via increasing fission with abnormal mitochondrial morphology. Excessive fission impaired the process of autophagy including the initiation phase, formation, and maturation of the autophagosome. In particular, the m.593T > C mutation upregulated the PARKIN-dependent mitophagy pathway. These alterations promoted an intrinsic apoptotic process for the removal of damaged cells. Our findings provide critical insights into the pathophysiology of maternally inherited deafness arising from tRNA mutation-induced defects in mitochondrial and cellular integrity.

Model construction and theoretical evaluation of the performance improvement of acetone-butanol-ethanol extractive fermentation by adding surfactant.

Severe butanol toxicity to the metabolism of solventogenic clostridia significantly impede the application of fermentative butanol as a biofuel. Liquid-liquid extraction is an efficient method to reduce the butanol toxicity by in-situ removing it in the extractant phase. Butanol mass transfer into extractant phase in static acetone-butanol-ethanol (ABE) extractive fermentation with biodiesel as the extractant could be enhanced by adding a tiny amount of surfactant such as tween-80. In the case of corn-based ABE extractive fermentation by Clostridium acetobutylicum ATCC 824 using biodiesel originated from waste cooking oil as extractant, addition of 0.14% (w/v) tween-80 could increase butanol production in biodiesel and total solvents production by 21% and 17%, respectively, compared to those of control under non-surfactant existence. Furthermore, a mathematical model was developed to elucidate the mechanism of enhanced ABE extractive fermentation performance. The results indicated that the mass transfer improvement was obtained by effectively altering the physical properties of the self-generated bubbles during ABE extractive fermentation, such as reducing bubble size and extending its retention time in extractant phase, etc. Overall, this study provided an efficient approach for enhancing biobutanol production by integration of bioprocess optimization and model interpretation.

Surgical management of mucosal contact headache.

BACKGROUND: Most research on mucosal contact headache has focused on mucosal contact between the nasal septum and middle or inferior turbinate. However, rarely have any studies explored how headache is related to the only one contact point between superior turbinate and nasal septum. OBJECTIVE: To explore how headache is related to the only one contact point between superior turbinate and nasal septum. METHODS: 80 patients with headache were selected. The mucosal contact between superior turbinate and nasal septum was removed to study the relationship between the contact point and headache, with a follow-up of 12 months. RESULTS: Headache symptoms in 56 cases disappeared entirely. Significant relief was observed in 20 patients, and unsatisfactory results in only 4 patients, with the success rate being 95%. CONCLUSION: Some patients with headaches who had intranasal mucosal contact areas benefitted from the surgery. Satisfactory results were achieved by endonasal surgery in 95% of our patients in whom intranasal contact points were believed to be the cause of their headaches who had a mucosal contact point between the superior turbinate and the septum.

The rice terpene synthase gene OsTPS19 functions as an (S)-limonene synthase in planta, and its overexpression leads to enhanced resistance to the blast fungus Magnaporthe oryzae.

Rice blast disease, caused by the fungus Magnaporthe oryzae, is the most devastating disease of rice. In our ongoing characterization of the defence mechanisms of rice plants against M. oryzae, a terpene synthase gene OsTPS19 was identified as a candidate defence gene. Here, we report the functional characterization of OsTPS19, which is up-regulated by M. oryzae infection. Overexpression of OsTPS19 in rice plants enhanced resistance against M. oryzae, while OsTPS19 RNAi lines were more susceptible to the pathogen. Metabolic analysis revealed that the production of a monoterpene (S)-limonene was increased and decreased in OsTPS19 overexpression and RNAi lines, respectively, suggesting that OsTPS19 functions as a limonene synthase in planta. This notion was further supported by in vitro enzyme assays with recombinant OsTPS19, in which OsTPS19 had both sesquiterpene activity and monoterpene synthase activity, with limonene as a major product. Furthermore, in a subcellular localization experiment, OsTPS19 was localized in plastids. OsTPS19 has a highly homologous paralog, OsTPS20, which likely resulted from a recent gene duplication event. We found that the variation in OsTPS19 and OsTPS20 enzyme activities was determined by a single amino acid in the active site cavity. The expression of OsTPS20 was not affected by M. oryzae infection. This indicates functional divergence of OsTPS19 and OsTPS20. Lastly, (S)-limonene inhibited the germination of M. oryzae spores in vitro. OsTPS19 was determined to function as an (S)-limonene synthase in rice and plays a role in defence against M. oryzae, at least partly, by inhibiting spore germination.

Fast Batch Production of High-Quality Graphene Films in a Sealed Thermal Molecular Movement System.

Chemical vapor deposition (CVD) growth of high-quality graphene has emerged as the most promising technique in terms of its integrated manufacturing. However, there lacks a controllable growth method for producing high-quality and a large-quantity graphene films, simultaneously, at a fast growth rate, regardless of roll-to-roll (R2R) or batch-to-batch (B2B) methods. Here, a stationary-atmospheric-pressure CVD (SAPCVD) system based on thermal molecular movement, which enables fast B2B growth of continuous and uniform graphene films on tens of stacked Cu(111) foils, with a growth rate of 1.5 µm s-1 , is demonstrated. The monolayer graphene of batch production is found to nucleate from arrays of well-aligned domains, and the films possess few defects and exhibit high carrier mobility up to 6944 cm2 V-1 s-1 at room temperature. The results indicate that the SAPCVD system combined with single-domain Cu(111) substrates makes it possible to realize fast batch-growth of high-quality graphene films, which opens up enormous opportunities to use this unique 2D material for industrial device applications.

Wide-Range Strain Sensors Based on Highly Transparent and Supremely Stretchable Graphene/Ag-Nanowires Hybrid Structures.

The increasing demand of electronic devices for physical motion detection has encouraged the development of highly elastic strain sensors. Especially, to capture wide-range physical movements, supremely stretchable and wide-range strain sensors are required. Here, a novel transparent, bendable, stretchable, and wide-range strain sensor based on a sandwich-like stacked graphene and Ag-nanowires hybrid structures is reported. The hybrid structures on 200% pre-stretched polyacrylate (PAC) are patterned which possess good bendability up to 2 mm radius, impressive stretchability up to 200% and comparatively low sheet resistance ≈200 Ω sq-1 with transparency 85%. Pre-stretched PAC technique enables the sensor to work well at extremely high strains and to sense the multidirectional strains efficiently. The Ag-nanowires pattern on PAC is fabricated via the bubble-template method, by which a uniform distribution of Ag-nanowires is achieved with significant connectivity throughout the surface. This not only decreases the power consumption but also enhances the sensitivity of the strain sensor. The demonstrated strain sensor is capable to sense strains between 5% and 200%, and the response time for this sensation is <1 ms.

A rapid method for simultaneous multi-gene mutation screening in children with nonsyndromic hearing loss.

Hearing loss (HL) is a common genetically heterogeneous sensory disorder, occurring in 1 to 3 per 1000 live births. In spite of the extraordinary genetic heterogeneity, variants in GJB2, MT-RNR1, and SLC26A4 genes have been considered as the main reasons of nonsyndromic hearing loss in Chinese population. We developed a rapid multiplex genetic screening system called the SNPscan assay technique which could detect the 115 mutations of the above three genes. This technique is a high-throughput and cost-saving SNP genotyping method. We found that the carrier rate of mutations in the GJB2 gene, MT-RNR1 gene, and SLC26A4 gene was 26.21%, 1.86%, and 25.46% of the patients with nonsyndromic hearing loss, respectively. Using this method, up to 50% of the patients in our study were identified to have hereditary HL caused by mutations in the three genes. It is applicable to not only genetic diagnosis of HL, but also molecular screening of other inherited diseases.

Powder, paper and foam of few-layer graphene prepared in high yield by electrochemical intercalation exfoliation of expanded graphite.

A facile and high-yield approach to the preparation of few-layer graphene (FLG) by electrochemical intercalation exfoliation (EIE) of expanded graphite in sulfuric acid electrolyte is reported. Stage-1 H2SO4-graphite intercalation compound is used as a key intermediate in EIE to realize the efficient exfoliation. The yield of the FLG sheets (<7 layers) with large lateral sizes (tens of microns) is more than 75% relative to the total amount of starting expanded graphite. A low degree of oxygen functionalization existing in the prepared FLG flakes enables them to disperse effectively, which contributes to the film-forming characteristics of the FLG flakes. These electrochemically exfoliated FLG flakes are integrated into several kinds of macroscopic graphene structures. Flexible and freestanding graphene papers made of the FLG flakes retain excellent conductivity (≈24,500 S m(-1)). Three-dimensional (3D) graphene foams with light weight are fabricated from the FLG flakes by the use of Ni foams as self-sacrifice templates. Furthermore, 3D graphene/Ni foams without any binders, which are used as supercapacitor electrodes in aqueous electrolyte, provide the specific capacitance of 113.2 F g(-1) at a current density of 0.5 A g(-1), retaining 90% capacitance after 1000 cycles.

Comparison of complications of the suprameatal approach and mastoidectomy with posterior tympanotomy approach in cochlear implantation: a meta-analysis.

BACKGROUND: Cochlear implantation (CI) is a popular procedure to preserve hearing in patients with severe-to-profound hearing loss. Evidence shows that the suprameatal approach (SMA) may help reducing the risk of the incidence of complications and shortening the surgery time, but there is still dispute. OBJECTIVES: The aim of this study was to compare the incidence of complications of SMA and the mastoidectomy with posterior tympanotomy approach (MPTA), and to find whether SMA yields better outcomes than MPTA. METHODS: We searched PubMed, the Cochrane Library, the Web of Science and Chinese Biomedical Literature databases, Chinese National Knowledge Infrastructure, the Chinese Science and Technology Journal Full-Text database, and Wangfang database. The latest data was accessed in March 2013. Review Manager 5.1 software was used for comprehensive quantification data analysis. RESULTS: Three studies were included in the meta-analysis, composed of 799 participants and reporting major and minor complications. The meta-analysis indicated no statistically significant difference in major and minor complications between the two approaches, except for facial nerve and chorda tympani injuries (OR = 0.13; 95% CI: 0.02, 0.67; p = 0.02; I(2) = 0%). CONCLUSIONS: Current evidence suggests that SMA may be clearly a good alternative to the classical surgery technique for CI in terms of reducing the incidence of facial nerve injury and chorda tympani sacrifice.

A Comparative Study of Hearing Handicap Inventory and Pure-Tone Audiometry Scores in Unilateral Hearing Impaired Patients.

Objective: To investigate the consistency between the hearing handicap inventory (HHI) and pure-tone audiometry (PTA) scores in assessing hearing status to provide valuable insights for clinical application. Methods: Retrospective analysis of clinical data and the HHI reporting status of 6540 patients admitted between April 2020 and July 2022 for self-reported unilateral hearing loss who met the study inclusion and exclusion criteria. The kappa coefficient was used to evaluate the consistency of HHI and PTA in assessing the hearing status of the participants. Results: The PTA results showed that among the 6540 participants, 3895 exhibited normal hearing, 1434 showed mild hearing loss, 809 presented with moderate hearing loss, and 402 showed severe hearing loss. The mean hearing thresholds from 0.5 to 4 kHz in healthy ears ranged from 3.65 to 18.45 dB HL, with a mean of 10.83 ± 5.29 dB HL; in ears affected by hearing loss, this ranged from 35 to 125 dB HL, with a mean of 69.63 ± 28.45 dB HL. The HHI scores showed that 4820 people had normal hearing, 1245 had mild-to-moderate hearing loss, and 475 had severe hearing loss. The kappa coefficients of normal, mild-to-moderate, and severe hearing loss were 0.312, 0.223, and 0.716, respectively (P = .001). The consistency between the 2 groups was particularly significant in the assessment of severe hearing loss. Using the PTA results as a benchmark, the sensitivity, specificity, positive predictive value, and negative predictive value of the HHI were found to be 73.08%, 87.83%, 95.60%, and 70.98%, respectively. Conclusion: The HHI and PTA results were consistent in the assessment of hearing status, particularly in the assessment of severe hearing loss, and the level of consistency between the 2 methods was high. The combined use of these tools can facilitate a comprehensive assessment of the auditory status of patients with hearing loss.

A novel intronic variant causing aberrant splicing identified in two deaf Chinese siblings with enlarged vestibular aqueducts.

OBJECTIVE: We aimed to evaluate the genotype-phenotype relationship in two Chinese family members with enlarged vestibular aqueduct (EVA). METHODS: We collected blood samples and clinical data from each pedigree family member. Genomic DNA was isolated from peripheral leukocytes using standard methods. Targeted next-generation sequencing and Sanger sequencing were performed to find the pathogenic mutation in this family. Minigene assays were used to verify whether the novel intronic mutation SLC26A4c.765+4A>G influenced mRNA splicing. RESULTS: Hearing loss in the patients with EVA was diagnosed using auditory tests and imaging examinations. Two pathogenic mutations, c.765+4A>G and c.919-2A>G were detected in SLC26A4. In vitro minigene analysis confirmed that c.765+4A>G variant could cause aberrant splicing, resulting in skipping over exon 6. CONCLUSIONS: The SLC26A4c.765+4A>G mutation is the causative variant in the Chinese family with EVA. Particular attention should be paid to intronic variants.

[Extranodal NK/T cell lymphoma, nasal type involving the larynx and digestive tract: a case report and literature review].

Extranodal NK/T cell lymphoma, nasal type（ENKTL） is a highly aggressive malignant tumor derived from NK cells. This article reports a case of ENKTL invading the larynx and digestive tract. The clinical clinical manifestations include hoarseness and intranasal masses.

The effect of SLC26A4 gene mutations on long-term rehabilitative outcomes in cochlear implant patients.

BACKGROUND: SLC26A4 gene mutations related to hearing loss patients can obtain good hearing and speech rehabilitation effects after cochlear implantation (CI). OBJECTIVE: To explore the long-term rehabilitative outcomes of CI in patients with different SLC26A4 mutation groups. MATERIAL AND METHODS: Clinical data of 71 patients with SLC26A4 gene mutations who received CI in the Second Hospital of Lanzhou University from 2012 to 2015 were retrospectively reviewed. According to the genetic test results, use One-way ANOVA analysis to compare the differences in auditory results, categories of auditory performance (CAP) and speech intelligibility rating (SIR) index questionnaire scores and speech recognition rates among different groups in 4-5 years after CI. RESULT: Compared with other genotypes of SLC26A4, the patients with homozygous mutation of c.919-2A > G in SLC26A4 had better hearing aid threshold at 500 Hz and better recognition rates of Yangyang words than other monoallelic mutation groups after CI (p < .05). CONCLUSIONS AND SIGNIFICANCE: The most common hot spot mutation of SLC26A4 gene is c.919-2A > G. The patients with homozygous mutation of c.919-2A > G in SLC26A4 gene had partly better hearing and speech rehabilitation than other monoallelic mutation groups after CI.

The value of nonverbal intelligence in cochlear implant.

BACKGROUND: Congenital sensorineural hearing loss is a common congenital condition. OBJECTIVES: The purpose of this study was to assess the correlation between nonverbal mental development and the effect of post-cochlear implant in children. MATERIAL AND METHODS: The study is a retrospective analysis of the CI program implemented at the ENT in the Lanzhou University Second Hospital (China). We reviewed data of 225 children who received CI between 2015 and 2018. Finally, 115 children met the inclusion criteria. Our hospital used The Griffith mental development scales to evaluate the preoperative non-verbal intelligence. The outcome of CI was evaluated using the categories of IT-MAIS, MUSS, CAP and SIR at 2 years after surgery. The associations between the preoperative non-verbal development quotient (DQ) and the postoperative outcomes were analyzed. RESULTS: Preoperative non-verbal DQ correlates with the long-term postoperative result, especially the Eye-hand co-ordination and Performance DQ. CONCLUSIONS AND SIGNIFICANCE: Preoperative non-verbal intelligence would predict postoperative effect. The single postoperative scale does not fully reflect the postoperative result.

Research on congenital severe-to-profound sensorineural hearing loss associated with central lucency of the bony island of the lateral semicircular canal.

BACKGROUND: Central lucency of the bony island of the lateral semicircular canal (LSCC) is commonly found in patients with congenital severe-to-profound sensorineural hearing loss (SNHL). OBJECTIVE: Exploring the significance of bony island lucency of LSCC in congenital severe-to-profound SNHL patients. MATERIAL AND METHODS: Retrospective measurements of the inner ear structures were made on axial temporal bone CT scans from 182 (364 ears) congenital severe-to-profound SNHL patients and 50 (100 ears) tympanic membrane perforation (TMP) patients. RESULTS: The incidence of bony island lucency of LSCC was 46.7% in the congenital severe-to-profound SNHL group and 0% in the TMP group. There was a statistically significant difference in inner ear structures among congenital severe-to-profound SNHL patients with normal inner ear structure and bony island lucency of LSCC, congenital severe-to-profound SNHL patients with normal inner ear structure and no bony island lucency of LSCC, and TMP patients. The importance of the bony island lucency of LSCC was further confirmed through multiple linear regression analysis. CONCLUSIONS AND SIGNIFICANCE: Bony island lucency may have significance in congenital severe-to-profound SNHL and may be a manifestation of largely overlooked SCC malformation or hypoplasia of the inner ear.

The mental health of paediatric cochlear implant recipients.

OBJECTIVES: To evaluate the mental health of paediatric cochlear implant users and analyse the relationship between six dimensions (movements, cognitive ability, emotion and will, sociality, living habits and language) and hearing and speech rehabilitation. METHODS: Eighty-two cochlear implant users were assessed using the Mental Health Survey Questionnaire. Age at implantation, time of implant use and listening modes were investigated. Categories of Auditory Performance and the Speech Intelligibility Rating Scale were used to score hearing and speech abilities. RESULTS: More recipients scored lower in cognitive ability and language. Age at implantation was statistically significant (p < 0.05) for movements, cognitive ability, emotion and will, and language. The time of implant usage and listening mode indicated statistical significance (p < 0.05) in cognitive ability, sociality and language. CONCLUSION: Timely attention should be paid to the mental health of paediatric cochlear implant users, and corresponding psychological interventions should be implemented to make personalised rehabilitation plans.

[Clinical research progress of bonebridge implantation].

Implantable bonebridge（BB） is suitable for patients over 5 years with conductive/mixed hearing loss and unilateral deafness, and the surgical approach depends on the anatomical structure of the patient's ear. Recent studies have shown that compared with other implantable hearing devices, implantable BB have more efficient hearing gain and lower incidence of complications. However, the postoperative effect of implantable BB on unilateral deafness patients and the poor compensation of low-frequency hearing threshold need to be further studied. This article reviews the clinical research on implantable BB, so as to provide some reference for clinicians to select hearing devices for patients individually.

[Scanning electron microscope of the human nasal septum].

Objective:Explore the significance of ultrastructural differences in tissue engineering, 3D printing, and rhinoplasty. Methods: 32 specimens （8 vomers, 8 perpendicular plates of ethmoid bone, 8 maxillary nasal crests, and 8 septal cartilage） of the nasal septum from patients with a nasal deviated septum and chronic sinusitis undergoing septoplasty were selected and examined using scanning electron microscopy. Results: The nasal septum of patients of different ages behaves similarly under the scanning electron microscope, and the bones of different parts of the nasal septum have similarities and differences. Conclusion:By observing the scanning electron micrograph of the nasal septum and analyzing the surface ultrastructure, it provides important information for the development of tissue engineering, assists in the refined modeling of 3D printing technology, and provides more ideal restoration materials for clinical operations.

A giant pyogenic granuloma gravidarum in the nasal cavity: A case report.

Pyogenic granuloma (PG) is a benign fibrovascular proliferative lesion on the skin and mucous membranes, but its pathogenesis remains unclear. PG usually occurs on the head and neck region, fingers and toes. The oral gingiva is the most common location for pregnant patients, while it is rarely found in the nasal cavity. This case is notable not only for its uncommon site and size but also for its gradual growth after delivery. Endoscopic surgery can achieve the desired cosmetic effect and a satisfactory airway. A rapidly growing hemorrhagic lesion in the nasal cavity should be considered as a differential diagnosis.

Verification of an iPSC line (LZUi002-A) from a patient with a novel mutation in the TBL1X gene.

More than 120 genes have been reported to be associated with deafness, and deletion of the TBL1X gene may cause deafness in humans. In this study, we generated an induced pluripotent stem cell (iPSC) line from dermal fibroblasts of a 34-year-old deaf person with a novel variant c.342_343insGCGGCG in the TBL1X gene. The induced patient-specific iPSC line with a normal karyotype and expressed pluripotent markers, it also shows differentiation totipotency and tridermogenesis in vivo. It may be a good model for studying hearing loss in vitro and it will benefit to the development of new therapies for deafness.