The distance between stapedial footplate and incus in otosclerosis surgery

Background: The measurement of the piston length during stapedotomy is important and it may have significant effects on the surgical outcome.Objective: To determine the piston length in a group of otosclerosis patients who underwent primary stapedotomy.Material and methods: Between Sep 2013 and Sep 2014, 85 patients with diagnosed otosclerosis underwent primary stapedotomy. Teflon prosthesis of 0.6 mm of diameter was used in all patients. The distance between medial surface of the long process of incus and center point of the stapedial footplate measured. The piston length calculated by adding 0.25 mm for the thickness of footplate and 0.50 mm for placement of the prosthesis into the vestibule.Results: The distance between stapedial foot plate and incus ranged from 3.50 to 4.50 mm. The mean distance was 3.95 ± 0.16 mm. In majority of cases(74.1%) piston length was 4.75 mm followed by 4.50 mm in 15.3% and 5.00 mm in 5.9%. Piston length was 4.25 mm in 3.5% and5.25 mm in only 1.2% of patients. There was no significant post-operative complication and air bone gap closure obtained in all patients.Conclusion: The most common distance between foot plate and incus is 4.00 mm. No case needed a piston longer than 5.25 mm or shorter than4.25 mm.

Trend of Storm Surge Induced by Typical Landfall Super Typhoons During 1975–2021 in the Eastern China Sea

Climate change affects the activity of global and regional tropical cyclones(TCs).Among all TCs,typical super typhoons(STYs)are particularly devastating because they maintain their intensity when landing on the coast and thus cause casualties,economic losses,and environmental damage.Using a 3D tidal model,we reconstructed the typhoon(TY)wind field to simulate the storm surge induced by typical STYs.The TY activity was then analyzed using historical data.Results showed a downtrend of varying degrees in the annual frequency of STYs and TCs in the Western North Pacific(WNP)Basin,with a significant trend change observed for TCs from 1949 to 2021.A large difference in the interannual change in frequency was found between STYs and TCs in the WNP and Eastern China Sea(ECS).Along the coast of EC,the frequency of landfall TCs showed a weak downtrend,and the typical STYs showed reverse micro growth with peak activity in August.Zhejiang,Fujian,and Taiwan were highly vulnerable to the frontal hits of typical STYs.Affected by climate change,the average lifetime maximum intensity(LMI)locations and landfall locations of typical STYs in the ECS basin showed a significant poleward migration trend.In addition,the annual average LMI and accumulated cyclone energy showed an uptrend,indicating the increasing severity of the disaster risk.Affected by the typical STY activity in the ECS,the maximum storm surge area also showed poleward migration,and the coast of North China faced potential growth in high storm surge risks.

Exploration of standard dosage for GnRH antagonist protocol and dosage adjustments after premature luteinizing hormone surge

The gonadotropin-releasing hormone (GnRH) antagonist protocol has emerged as an efficacious alternative to the GnRH agonist protocol for controlled ovarian hyperstimulation (COH) during in vitro fertilization (IVF) cycles, and has been demonstrated applicability in infertile female patients with diverse ovarian responses. While the clinical implementation of the antagonist COH protocol has achieved widespread consensus, opportunities for refinement persist. Therefore, this review article focuses on the advantages and disadvantages of GnRH antagonist protocol, the selection of optimal standard doses, and the strategies for adjusting antagonist doses after the premature luteinizing hormone (LH) surge, aiming to provide more reasonable and scientific recommendations for the application of this scheme.

Revision surgery for otosclerosis:An overview

Stapes surgery for otosclerosis has been proved to be a very satisfying procedure. However, the condition is difficult for the patients with no or little hearing gain after surgery and for those who had sudden or gradual hearing loss after a successful air-bone gap closure in the follow-up period. The issue of re-exploring the middle ear is challenging. A general review of this subject from several points of view remains lacking. In this study, articles related with the revision surgery for otosclerosis have been reviewed after a Pub Med research and common and/or contradictory points were documented. The aim of this study is to give an insight to diagnostic and therapeutic approaches forthe clinicians in patients who need a revision surgery. In conclusion, prosthesis problems, loose prosthesis in stapedotomy and migrated prosthesis in stapedectomy are the most common causes for revision surgery. Most important indicators which effect better hearing outcome following revision surgery are those ears with the presence of incus, with no obliteration of oval window, with small fenestra stapedotomy and the experience of surgeon. The risk of neurosensorial hearing loss in revision cases is not high but the hearing gain is limited as compared to primary cases. The rate of 10 d B air-bone gap closure is around 60%-70% at most and even less promising results have been reported. Patient's demands and expectations have to be clarified in a realistic way.

A typhoon-induced storm surge numerical model with GPU acceleration based on an unstructured spherical centroidal Voronoi tessellation grid

Storm surge is often the marine disaster that poses the greatest threat to life and property in coastal areas.Accurate and timely issuance of storm surge warnings to take appropriate countermeasures is an important means to reduce storm surge-related losses.Storm surge numerical models are important for storm surge forecasting.To further improve the performance of the storm surge forecast models,we developed a numerical storm surge forecast model based on an unstructured spherical centroidal Voronoi tessellation(SCVT)grid.The model is based on shallow water equations in vector-invariant form,and is discretized by Arakawa C grid.The SCVT grid can not only better describe the coastline information but also avoid rigid transitions,and it has a better global consistency by generating high-resolution grids in the key areas through transition refinement.In addition,the simulation speed of the model is accelerated by using the openACC-based GPU acceleration technology to meet the timeliness requirements of operational ensemble forecast.It only takes 37 s to simulate a day in the coastal waters of China.The newly developed storm surge model was applied to simulate typhoon-induced storm surges in the coastal waters of China.The hindcast experiments on the selected representative typhoon-induced storm surge processes indicate that the model can reasonably simulate the distribution characteristics of storm surges.The simulated maximum storm surges and their occurrence times are consistent with the observed data at the representative tide gauge stations,and the mean absolute errors are 3.5 cm and 0.6 h respectively,showing high accuracy and application prospects.

Metaverse Upsurge Drives Virtual Human Industry to Upgrade

The concept of a virtual human is rapidly fermenting with the boom of the metaverse in 2020.In March 2021,Roblox,a game company focusing on the socialization of teenagers’games and the free realization of UGC,went public.In its prospectus,Roblox is defined as the concept of the metaverse.Under this background,as the direct embodiment of“virtual identity”and“virtual reality coexisting”under the concept of the metaverse,the emerging definition of virtual human and its representative virtual image has gradually caught the attention of the public.

Diagnostic performance of high resolution computed tomography in otosclerosis

AIM To determine the sensitivity and specificity of high resolution computed tomography(HRCT) in the diagnosis of otosclerosis.METHODS A systematic literature review was undertaken to include Level I-III studies(Oxford Centre for Evidenced based Medicine) that utilised HRCT to detect histology confirmed otosclerosis.Quantitative synthesis was then performed.RESULTS Based on available level III literature,HRCT has a relatively low sensitivity of 58%(95%CI: 49.4-66.9),a high specificity,95%(95%CI: 89.9-98.0) and a positive predictive value of 92%(95%CI: 84.1-95.8).HRCT is better at diagnosing the more prevalent fenestral form of otosclerosis but remains vulnerable to inframillimetre,retrofenestral and dense sclerotic lesions,despite the advent of more advanced CT scanners with improved collimation.CONCLUSION Whilst the diagnosis of otosclerosis remains largely clinical,HRCT remains the gold standard imaging of choice for the middle ear and serves as a useful adjunct to the clinician,helping to delineate extent of disease and exclude other causes.

Otosclerosis: Contribution of Computed Tomography and Radio-Anatomical Correlations

Otosclerosis is an osteodystrophia of the otic capsule, responsible for hearing loss by blocking of the stapes footplate. The purpose of this study was to evaluate the reliability of computed tomography (CT) in the positive diagnosis of otosclerosis, to compare the radiological findings to those intraoperatively, and to seek a correlation between imaging data and postoperative audiometric results. This is a retrospective study of 60 patients having otosclerosis, treated in our department between 2009 and 2011. All patients underwent an otoscopic examination, pure tone and vocal audiometry, impedancemetry and petrous CT scan. At petrous CT scan, a footplate thickening was found in 9 cases. Labyrinthine bone hypodensity was noted in 51 cases. Sensitivity of CT in the diagnosis of otosclerosis was 100%. Regarding the operative findings and their correlation with imaging, we found that among the 7 facial canal procidences reported intraoperatively, CT had identified 6, with a sensitivity of 86%. Of the 53 facial nerve in normal position intraoperatively, CT had only identified 34, with a specificity of 64%. Regarding the ossicles, there were 6 cases of abnormalities of the incus, among them 3 were identified on CT, with a sensitivity of 50%. The 54 patients with normal ossicular chain intraoperatively were all identified as such on CT, with a specificity of 100% (p = 0.001). For correlation between imaging and postoperative results, it was found that patients with extended otosclerosis had lower postoperative audiometric improvement than those having localized disease (p < 0.05). Computed tomography is necessary for the diagnosis of otosclerosis. It also helps, with good sensitivity and specificity, seeking for anatomical variants that the surgeon could possibly encounter during surgical procedure. Finally, there is a statistically significant correlation between imaging data and postoperative audiometric results, allowing establishing a functional prognosis even before surgery.

Does bilateral otosclerosis make pre-operative bone conduction more inaccurate?

Objectives:To assess whether bilateral otosclerosis renders pre-operative bone conduction more inaccurate by increasing the Carhart effect.Methods:Retrospective review of a database of pre and post-operative audiograms of 745 ears with otosclerosis treated with stapedectomy from 2013 to 2020 in a tertiary centre.Main outcome measures:Change in bone conduction after stapedectomy for otosclerosis in:unilateral otosclerosis(U1);bilateral otosclerosis undergoing first side surgery(B1);bilateral otosclerosis undergoing second side surgery(B2).The magnitude of change in bone conduction post-operatively within and between each group.Results:The average difference in pre and post-operative bone conduction was significant within in all groups(T-stat>2 and P-value<0.05)with the greatest change observed in the U1 group.Analysis of average change in bone conduction between groups did not reach statistical significance(Pvalue=0.37).Analysis of change per frequency demonstrated the greatest change in bone conduction post-operatively at 2000 Hz in all groups.The magnitude of change at 2000 Hz was the greatest in the bilateral groups;however,it did not reach statistical significance when compared to the unilateral group(P-value=0.36).Conclusions:This is the first study in the literature to assess the accuracy of pre-operative bone conduction in bilateral versus unilateral otosclerosis.There is no evidence that pre-operative bone conduction in bilateral otosclerosis is more inaccurate than in unilateral disease.In order to assess accuracy of pre-operative bone conduction in otosclerosis a reliable method of assessing post-operative bone conduction is required,without assumption of its equivalence to cochlear reserve.

Measuring the density of the fissula antefenestram and the section of the basal turn of the cochlea:Are they useful in the radiological diagnosis of otosclerosis?

Introduction:The role of objective parameters in terms of improvement of the accuracy of highresolution computed tomography(HRCT)of the temporal bone in the diagnosis of otosclerosis remains unclear.Objectives:To investigate the relationship between the density of the fissula antefenestram(FAF)and of the width of the transversal section of the basal turn of the cochlea(BTC),and the diagnosis of otosclerosis.Methods:This is a retrospective study in which preoperative HRCT data from ears of patients submitted to stapedotomy due to otosclerosis(case group)were evaluated.For the control group,normal hearing ears having undergone HRCT for other purposes were included.Case and control HRCT images were objectively assessed by an experienced blinded radiologist.During this evaluation,measurements of the relative radiological density of the FAF and of the transversal section of the BTC were obtained.The results were compared between the groups.Also,a receiver operating characteristic curve was created and the area under the curve(AUC)was calculated for each variable.Significance level was set at.05.Results:40 ears were included in each group.Case ears presented reduced values for the relative radiological density on the FAF(p-value<0.0001).Moreover,ears with otosclerosis(p-value:0.022)presented lower transversal section of the BTC.The AUC for these variables reached 0.929 and 0.646,respectively.Conclusions:Otosclerotic ears present reduced radiological density on the FAF and narrower BTC.The relative density of the FAF also shows a great diagnostic power in the context of this disease.

Malleostapedotomy for otosclerosis,our experience of nitinol piston on twelve patients

Objective:Malleostapedotomy allows to completely by-pass the incus in otosclerosis surgery.Recently its use has been rivaled by hydroxyapatite cement for cases of mild and moderate necrosis of the incus.However,it remains gold standard for cases of extensive necrosis,incus dislocation,or epitympanic fixation.Modern heat-crimping pistons make surgery easier and safer.This study focuses on our experience with this technique.Methods:Retrospective analysis of patient’s files and pre-and post-operative audiograms,for cases of surgically treated otosclerosis with malleostapedotomy.Results:Twelve patients underwent malleostapedotomy for otosclerosis between 2011 and 2019.Amongst them there were 10 revision surgeries and 2 primary cases.75%had incus long-process necrosis,17%had epitympanic fixation and one had a history of incus transposition.Nine patients(75%)had closure of air-bone gap(ABG)of<10 dB(p<0.001)and 11(92%)had a threshold of 20 dB(p<0.001).Mean pre-operative ABG was 31 dB(15 dBe55 dB),and mean post-operative ABG was 7 dB(0 dBe21 dB;p<0.001).There was no sensorineural hearing loss nor any other post-operative complication.Conclusions:Malleostapedotomy is a safe and reliable technique,allowing an ABG closure comparable to conventional incus to vestibule prosthesis.It remains the preferred technique whenever the incus cannot be used.

Stability of computed tomography densitometry in patients with otosclerosis:a two-year follow-up

Objectives:To quantify the progression of otosclerosis in the unoperated ear between two stapedotomy procedures for patients with bilateral otosclerosis which can help to determine whether a HRCT scan should be re-performed before the second surgery for patients who already received HRCT imaging before the initial surgery.Methods:35 patients who underwent bilateral stapedotomy were included.Two rounds of HRCT examination and audiometry were performed at the time of the first surgery and second surgery on the ear that was not operated on during the initial surgery.The relationship between the changes in HRCT densitometry and audiometry over time was analyzed.Results:The second round of HRCT did not add significant information about the changes to the otosclerosis lesions in either the imaging diagnosis or the HRCT density values except for small changes in the HRCT densitometry readings at the area anterior to the inner auditory(P=0.01).While the changes in HRCT manifestation are small,changes near the fissula ante fenestram(FAF)were still positively correlated with the air bone gap(ABG)of patients(p=0.031,r=0.388).Conclusions:The progression of lesions in otosclerosis is slow resulting in small and insignificant changes to the HRCT features.Therefore,a repeat HRCT evaluations prior to surgery is not necessary for patients who have had a previous HRCT evaluation within 2 years of the operation.The small changes in HRCT manifestation near the FAF were still correlated with negative effects on the ABG which could cause worsened hearing thresholds over this timeframe。

A REVOLUTIONARY PATH IN TREATMENT OF OTOSCLEROSIS AND ITS RELEVANCE IN CHINA

Otosclerosis was first discovered by Valsalva in 1704[1], and the term was first used by Anton von Troltsch in 1872 to differentiate from tympanosclerosis[2].Normallythe otic cyst in human remains stationary after full development and contains no visible activated osteoblasts or

Novel layout design of 4H-SiC merged PiN Schottky diodes leading to improved surge robustness

A method to improve the surge current capability of silicon carbide(SiC)merged PiN Schottky(MPS)diodes is presented and investigated via three-dimensional electro-thermal simulations.When compared with a conventional MPS diode,the proposed structure has a more uniform current distribution during bipolar conduction due to the help of the continuous P+surface,which can avoid the formation of local hotspots during the surge process.The Silvaco simulation results show that the proposed structure has a 20.29%higher surge capability and a 15.06%higher surge energy compared with a conventional MPS diode.The bipolar on-state voltage of the proposed structure is 4.69 V,which is 56.29%lower than that of a conventional MPS diode,enabling the device to enter the bipolar mode earlier during the surge process.Furthermore,the proposed structure can suppress the occurrence of‘snapback'phenomena when switching from the unipolar to the bipolar operation mode.In addition,an analysis of the surge process of MPS diodes is carried out in detail.

Assessment of Storm Surge and Flood Inundation in Chittagong City of Bangladesh Based on ADCIRC and GIS

Coastal flooding caused by tropical cyclones has long been a major threat to life,property,and infrastructure in coastal zones.This study assessed the risk of flooding in Chittagong,southeastern Bangladesh,under extreme sea level scenarios caused by high astronomical tides and storm surges.The Jelesnianski typhoon model and the ADvanced CIRCulation hydrodynamic model were used to simulate 91 typhoons that occurred in the Bay of Bengal between 1981 and 2017,and observational data were used for model validation.The inundation model was based on a digital elevation model and a seed spread algorithm,and a geographical information system was used to visualize the flood risk.Under four scenarios,the changes in flood levels caused by sea level rise had no signifi-cant influence on the extent of flooding in Chittagong.At flood levels of 8.82m(50-year storm surge without sea level rise)and 8.89 m(50-year storm surge with sea level rise),the maximum estimated area of inundation was 11.35 km^(2).The western coastal and southeastern river coastal plain areas of Chittagong have the highest risk of inundation due to their low-lying terrain.At flood levels of 9.83m(100-year storm surge without sea level rise)and 9.97m(100-year storm surge with sea level rise),the maximum simulated flood extent was 36.44km^(2).Simulated floodwaters propagated in a south–north direction,and most of the northern areas of the city are at risk of inundation under these scenarios.

Numerical Study on Aerodynamic Performance of Floating Dual-Rotor Wind Turbines in Heave and Surge Motions

Compared with the traditional wind turbine of a single rotor,dual-rotor wind turbines(DRWTs)have higher wind energy capture efficiency and a more complex structure.Therefore,the aerodynamic performance of the DRWT installed on the floating platform will be greatly affected by the motion caused by wind and wave loads.In this paper,5 MW and 750 kW single rotor wind turbines(SRWTs)are combined into a 5 MW-5 MW DRWT and a 5 MW-750 kW DRWT,and their power output and wake field characteristics in different motions are studied.The flow field is obtained by solving the Reynolds-averaged Navier–Stokes equation(RANS).The overset grid technique is employed to achieve the large-amplitude multiple-degree-of-freedom motion of the DRWT.The overall performance of the 5 MW single rotor wind turbine is determined by a numerical method.For the DRWTs,numerical results show that the surge motion and heave motion both have a negative effect on the power output of the DRWT.The surge motion is a critical factor that causes the power output of the DRWT to periodically change with motion.The average power output of the DRWT influenced by motion is lower than that of a DRWT with a fixed bottom.The surge motion significantly disturbs the wake of the DRWT due to the mutual interference between the upstream and downstream rotors.Under the influence of heave motion,low-velocity regions downstream of the blade tip are enhanced.This study indicates that attenuating the surge and heave motion of offshore DRWT is very significant for improving its efficiency and should be taken into consideration during the design procedure.

Assessment of typhoon storm surge disaster scale based on expansion model

The South China Sea suffers strongly from the typhoon storm surge disasters in China,and its northern coastal areas are facing severe risks.Therefore,it is necessary and urgent to establish an assessment system for rating typhoon storm surge disaster.We constructed an effective and reliable rating assessment system for typhoon storm surge disaster based on the theories of over-threshold,distribution function family,and composite extreme value.The over-threshold sample was used as the basis of data analysis,the composite extreme value expansion model was used to derive the design water increment,and then the disaster level was delineated based on the return period level.The results of the extreme value model comparison show that the Weibull-Pareto distribution is more suitable than the classical extreme value distribution for fitting the over-threshold samples.The results of the return period projection are relatively stable based on different analysis samples.Taking the 10 typhoon storm surges as examples,they caused landfall in the Guangdong area in the past 10 years.The results of the assessment ranking indicate that the risk levels based on the return period levels obtained from different distributions are generally consistent.When classifying low-risk areas,the classification criteria of the State Oceanic Administration,China(SOA,2012)are more conservative.In the high-risk areas,the results of the assessment ranking based on return period are more consistent with those of the SOA.

耳内镜下微钻和三棱针镫骨底板开窗人工镫骨植入术治疗耳硬化疗效比较

目的比较耳内镜下使用微钻和三棱针二种工具行镫骨底板开窗人工镫骨植入术治疗耳硬化的听力效果、并发症。方法2018年3月—2023年2月本院收治的接受耳内镜下镫骨手术的耳硬化患者38例(48耳),48耳均在耳内镜下行镫骨底板开窗人工镫骨植入术,术中分别采用微钻(微钻组,26耳)和三棱针(三棱针组,22耳)进行镫骨底板开窗,植入纯钛质人工镫骨假体Piston。比较2组患者的术后听力效果,以及眩晕、面瘫、感音神经性耳聋、术中镫骨意外等并发症情况。结果48耳术后气导(AC)、骨导(BC)、气骨导差(ABG)均较术前改善,差异具有统计学意义(P值均<0.05)。其中微钻组AC改善(23.5±12.6)dB HL,BC改善(3.4±6.6)dB,ABG缩小(20.1±5.6)dB HL;三棱针组AC改善(21.4±11.8)dB HL,BC改善(3.3±6.8)dB HL,ABG缩小(18.1±4.3)dB HL,2组间差异无统计学意义(P>0.05)。术后2组均未发生面瘫和感音神经性耳聋,2组在术后眩晕和术中镫骨意外方面,差异也没有统计学意义(P值均>0.05)。结论耳内镜下人工镫骨植入术中使用微钻和三棱针行镫骨底板开窗疗效相似,二者都需要依赖精细的手术技巧和经验,微钻比三棱针更方便、更安全。

航天供配电系统舵机负载浪涌抑制策略研究

随着航天器供配电系统的快速发展,大功率机电负载的使用逐渐增多,对其负载供电品质的要求也日益严格。针对高压大功率舵机负载工作状态变化大、要求响应快、动态指标高,导致机电舵机负载在工作过程中会频繁出现换向、加减速的工作特点,对电动舵机高速制动过程中产生的反灌能量进行供配电系统影响分析,提出供配电系统反灌浪涌抑制策略,提升供配电系统供电可靠性,确保航天器飞行任务中舵机负载的全程可靠运行。

1300—2019年江苏沿海风暴潮灾害时空分布特征

历史上江苏沿海曾频发2类风暴潮灾害,给当地带来了巨大损失。建立该地区长时间尺度的风暴潮灾害序列对了解过去与预测未来意义重大。以历史文献、地方志、海洋灾害公报等记载的风暴潮资料为基础,建立了风暴潮灾害识别体系,重建了1300—2019年江苏沿海风暴潮灾害序列,分析了风暴潮灾害时空变化规律,探究了其与气候异常和黄河、长江入海口变迁之间的关系。结果表明:江苏沿海地区主要受台风风暴潮灾害的影响,1300—2019年间共发生246次风暴潮灾害,平均周期为2.9年,且近100年来发生频率有增大的趋势;小波分析结果显示,风暴潮灾害年际变化存在17年、61年和115年的时间尺度周期,其中115年周期最为明显。海气相互作用影响下,厄尔尼诺活跃年江苏沿海台风风暴潮灾害偏少;气温与台风风暴潮灾害频次有一定的正相关性,但其影响机制尚不明确。盐城、南通和苏州为风暴潮灾害高发地区,常州和无锡发生频率较小。在气候变暖与江苏海岸冲淤变化的作用下,1855年后盐城和南通地区风暴潮灾害发生频率增加,连云港地区明显增加;随着海岸线的变迁与长江河口的演变,镇江、扬州、泰州与苏锡常地区受风暴潮灾害影响减少。