Electronic nose(eNose) is a modern bioelectronic sensor for monitoring biological processes that convert CO_(2) into valueadded products, such as products formed during photosynthesis and microbial fermentation. eNose...Electronic nose(eNose) is a modern bioelectronic sensor for monitoring biological processes that convert CO_(2) into valueadded products, such as products formed during photosynthesis and microbial fermentation. eNose technology uses an array of sensors to detect and quantify gases, including CO_(2), in the air. This study briefly introduces the concept of eNose technology and potential applications thereof in monitoring CO_(2) conversion processes. It also provides background information on biological CO_(2) conversion processes. Furthermore, the working principles of eNose technology vis-à-vis gas detection are discussed along with its advantages and limitations versus traditional monitoring methods. This study also provides case studies that have used this technology for monitoring biological CO_(2) conversion processes. eNose-predicted measurements were observed to be completely aligned with biological parameters for R~2 values of 0.864, 0.808, 0.802, and 0.948. We test eNose technology in a variety of biological settings, such as algae farms or bioreactors, to determine its effectiveness in monitoring CO_(2) conversion processes. We also explore the potential benefits of employing this technology vis-à-vis monitoring biological CO_(2) conversion processes, such as increased reaction efficiency and reduced costs versus traditional monitoring methods. Moreover, future directions and challenges of using this technology in CO_(2) capture and conversion have been discussed. Overall, we believe this study would contribute to developing new and innovative methods for monitoring biological CO_(2) conversion processes and mitigating climate change.展开更多
The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 mm.This study aims to fill the gap in the experimental and analytic...The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 mm.This study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic penetration.In the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/s.Severe erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered projectiles.By examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration tests.Furthermore,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation mechanism.Finally,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present study.Depending upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or hemispherical.Due to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.展开更多
The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual...The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.展开更多
Shimmy can reduce the service life of the nose landing gear, affect ride comfort, and even cause fuselage damage leading to aircraft crashes. Taking a light aircraft as the research object, the torsional freedom of la...Shimmy can reduce the service life of the nose landing gear, affect ride comfort, and even cause fuselage damage leading to aircraft crashes. Taking a light aircraft as the research object, the torsional freedom of landing gear around strut axis and lateral deformation of tire are considered. Since the landing gear shimmy is a nonlinear system, a nonlinear mechanical model of the front landing gear shimmy is established. Sobol index method is proposed to analyze the influence of structural parameters on the stability region of the nose landing gear, and Routh-Huritz criterion is used to verify the reliability of the analysis results of Sobol index method. We analyse the effect of torsional stiffness of strut, caster length, rated initial tire inflation pressure, rake angle, and vertical force on the stability region of theront landing gear. And the research shows that the optimization of the torsional stiffness of the strut and the caster length of the nose landing gear should be emphasized, and the influence of vertical force on the stability region of the nose landing gear should be paid attention to.展开更多
目的:探讨在(疾病)诊断相关分类(diagnosis related groups,DRGs)形势下,腹腔镜结直肠癌经自然腔道取标本(NOSES)手术方式改进及其可行性。方法:回顾性分析安阳市肿瘤医院2019年2月至2021年2月实施DRGs的42例改进后的腹腔镜结直肠癌NOSE...目的:探讨在(疾病)诊断相关分类(diagnosis related groups,DRGs)形势下,腹腔镜结直肠癌经自然腔道取标本(NOSES)手术方式改进及其可行性。方法:回顾性分析安阳市肿瘤医院2019年2月至2021年2月实施DRGs的42例改进后的腹腔镜结直肠癌NOSES术,并与同期进行常规腹腔镜结直肠癌手术的238例患者在费用、治疗结果、并发症等方面相比较。结果:NOSES改进组42例患者DRGs控费成功率为95.2%(40/42),与常规腹腔镜组在DRGs费用及近期并发症发生率方面无显著性差异(P>0.05)。结论:腹腔镜结直肠癌NOSES改进手术可以达到DRGs费用标准,手术安全可靠,应用双7号丝线代替部分直线切割闭合器是可行的。展开更多
Traditionally fermented shrimp paste has a long fermentation period and is susceptible of external factors,which leads to unstable quality and limits its development and application.Therefore,the purpose of this study...Traditionally fermented shrimp paste has a long fermentation period and is susceptible of external factors,which leads to unstable quality and limits its development and application.Therefore,the purpose of this study is to analyze the flavor changes in the shrimp paste fermentation process and screen out the key volatile aroma components in the shrimp paste to control the flavor quality of the shrimp paste products.The overall odor profile was detected by the electronic nose.A total of 106 volatile flavor compounds in the shrimp paste samples at different fermentation stages were identified by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)and headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS).The main aroma components alcohols,aldehydes,pyrazines and other substances in the fermentation process showed an overall upward trend.A total of 17 key volatile aroma components in shrimp paste at different fermentation stages were identified by the relative aroma activity value(ROAV)method.The combination of electronic nose,SPME-GC-MS and HS-GC-IMS could comprehensively reflect the changes of volatile components in shrimp paste at different fermentation stages,which helps to further understand the mechanism of shrimp paste flavor formation and provides a basis for the regulation of the flavor quality of shrimp paste products.展开更多
Background:This study aimed to review treatments and evaluate the aesthetic outcomes,complications,and reoperation rates regarding surgical correction for a postoperative contracted nose.Methods:PubMed,MEDLINE,and Emb...Background:This study aimed to review treatments and evaluate the aesthetic outcomes,complications,and reoperation rates regarding surgical correction for a postoperative contracted nose.Methods:PubMed,MEDLINE,and Embase databases were searched for studies detailing aesthetic outcomes and complications of surgical correction of a contracted nose.Surgical procedures,adjuvant treatment,outcomes,and complications were synthesized and analyzed.Results:Nine articles encompassing 376 patients were included in the systematic review,and six articles(198 participants)were included in the meta-analysis.The most frequently used graft material was the autologous rib cartilage(61.1%).Surgical procedures were heterogeneous in these studies.The nasolabial angle reduced by 9.52°(95%confidence interval(CI):(-11.95,-7.09),P<0.0001),and the nasal length increased significantly(standardized mean difference(SMD)=2.25,95%CI:(1.26,2.23),P<0.00001).However,the evidence was insufficient to determine a significant change in the columellar-labial angle(SMD=-0.95,95%CI:(-2.19,0.29),P=0.13)and columellar-lobular angle(SMD=2.39,95%CI:(-1.20,5.97),P=0.19).Aesthetic dissatisfaction(12.5%)and infection(4.5%)were the most commonly reported complications.Reoperation was performed in 5.3%of patients.Conclusion:Surgical correction can increase the nasal length,reduce the nasolabial angle,and have a low reoperation rate.No significant improvement in the columellar-labial or columellar-lobular angle was observed.展开更多
Introduction: Acute mastoiditis is the most common complication of Acute Otitis Media (AOM) and it’s the cause of serious morbidity. There is no standard universally agreed-upon management approach to acute mastoidit...Introduction: Acute mastoiditis is the most common complication of Acute Otitis Media (AOM) and it’s the cause of serious morbidity. There is no standard universally agreed-upon management approach to acute mastoiditis. This study aims to view the clinical presentation and management approaches in Khartoum Ear, Nose and Throat Hospital. Methodology: This is a prospective case series and a hospital-based study conducted at Khartoum Ear, Nose and Throat Hospital during the period from November 2017 to November 2019. A total of 61 patients were included in the study. Results: The median age at presentation is 5 years old, males are more affected than females with a ratio of 1.35:1, and the mean duration of symptoms prior to hospital admission was 9.6 days. The most common presenting symptoms were otalgia (83.3%), ear discharge (83.3%) and post-auricular swelling (83.3%), and the most common signs at admission were tenderness over the mastoid (95.1%), retroauricular swelling and protrusion of the auricle (82%), and redness over the mastoid (77%). The abnormal tympanic membrane was found in all patients with central perforation being the commonest finding (73.8%), and bulging tympanic membrane (21.3%). 34.4% of patients received oral antibiotics before admission and the mean duration of symptoms prior to admission increased significantly in those who received antibiotics 12.7 days in comparison to those who didn’t 8.3 days. Only 52.5% of patients had a past history of recurrent acute otitis media, and 8.2% had a past history of acute mastoiditis. All the patients with recurrent mastoiditis had a past history of recurrent acute otitis media. Computed Tomography (CT) scans were obtained for 50.8% and 83.9% of those scans showed coalescent mastoiditis. Further evidence of intracranial extension was found in 6.5% and Magnetic Resonance Imaging (MRI) was obtained for them. Of the study group, 67.2% presented with subperiosteal abscess, 4.9% with facial nerve palsy and 3.3% with brain abscess. Thirteen patients with no complications were managed initially with injectable and topical antibiotics and were successful in only 6 of them (46%), abscess incisions and drainages were needed in 46 patients and were successful in 34 of them (73.9%). Eighteen patients (29.5%) needed mastoidectomy and all of them were managed successfully (100%). One patient (1.6%) was referred for intracranial abscess drainage in a specialized hospital, also one patient (1.6%) initially presented with intracranial abscess died on the second day of admission and 96.8% were discharged in good condition. The mean duration of hospital stay was 7.5 days. Conclusion: Patients present to the hospital after a prolonged period with a higher rate of complications, and the delayed presentation increased significantly in patients who received oral antibiotics prior to admission. Conservative medical treatment in non-complicated acute mastoiditis was ineffective in more than half of the patients and abscess incision and drainage and/or mastoidectomy are often necessary for the management.展开更多
目的探讨在加速康复外科(enhanced recovery after surgery concept,ERAS)理念下经自然腔道取标本手术(natural orifice specimen extraction surgery,NOSES)对左半结肠癌患者术后应激指标及恢复的影响。方法选取2019年10月~2020年8月...目的探讨在加速康复外科(enhanced recovery after surgery concept,ERAS)理念下经自然腔道取标本手术(natural orifice specimen extraction surgery,NOSES)对左半结肠癌患者术后应激指标及恢复的影响。方法选取2019年10月~2020年8月大连大学附属中山医院收治的60例左半结肠癌患者,采用随机数字表法将其分为NOSES+ERAS组(n=31)和ERAS组(n=29)。NOSES+ERAS组患者采用在ERAS理念下的NOSES,ERAS组患者采用在ERAS理念下的腹腔镜结肠癌根治术。比较两组患者的术后临床恢复指标(术后首次排气时间、进流食时间、首次排便时间、术后住院时间),实验室检查指标[白细胞计数(white blood cell,WBC)、C反应蛋白(C-reactive protein,CRP)、白细胞介素-6(interleukin-6,IL-6)、血清淀粉样蛋白A(serum amyloid A protein,SAA)],术后并发症的发生情况以及术后疼痛数字分级评分(numerical rating scale,NRS)。结果与ERAS组比较,NOSES+ERAS组患者的术后首次排气时间、进流食时间、首次排便时间及住院时间均缩短(P均<0.05);术后第3天的WBC降低(P<0.05),术后第1、3、5天的CRP、IL-6、SAA水平降低(P<0.05);术后并发症发生率降低(P<0.05);术后12、24、48h的疼痛NRS评分降低(P<0.05)。结论NOSES在ERAS理念下可以有效减少左半结肠癌患者术后疼痛、住院时间、首次排气时间、首次排便时间、进流食时间,降低机体炎症,减少瘢痕,促进患者恢复。展开更多
基金supported by the National Key Technologies R & D Program of China during the 14th Five-Year Plan period (No. 2021YFD1700904)Henan Provincial Important Project (No. 221100320200)+1 种基金State Key Laboratory of Wheat and Maize Crap Science (No. SKL2023ZZ09)the Henan Center for Outstanding Overseas Scientists (No. GZS2021007)。
文摘Electronic nose(eNose) is a modern bioelectronic sensor for monitoring biological processes that convert CO_(2) into valueadded products, such as products formed during photosynthesis and microbial fermentation. eNose technology uses an array of sensors to detect and quantify gases, including CO_(2), in the air. This study briefly introduces the concept of eNose technology and potential applications thereof in monitoring CO_(2) conversion processes. It also provides background information on biological CO_(2) conversion processes. Furthermore, the working principles of eNose technology vis-à-vis gas detection are discussed along with its advantages and limitations versus traditional monitoring methods. This study also provides case studies that have used this technology for monitoring biological CO_(2) conversion processes. eNose-predicted measurements were observed to be completely aligned with biological parameters for R~2 values of 0.864, 0.808, 0.802, and 0.948. We test eNose technology in a variety of biological settings, such as algae farms or bioreactors, to determine its effectiveness in monitoring CO_(2) conversion processes. We also explore the potential benefits of employing this technology vis-à-vis monitoring biological CO_(2) conversion processes, such as increased reaction efficiency and reduced costs versus traditional monitoring methods. Moreover, future directions and challenges of using this technology in CO_(2) capture and conversion have been discussed. Overall, we believe this study would contribute to developing new and innovative methods for monitoring biological CO_(2) conversion processes and mitigating climate change.
基金the National Natural Science Foundation of China(Grant No.12102050)the Open Fund of State Key Laboratory of Explosion Science and Technology(Grant No.SKLEST-ZZ-21-18).
文摘The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 mm.This study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic penetration.In the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/s.Severe erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered projectiles.By examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration tests.Furthermore,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation mechanism.Finally,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present study.Depending upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or hemispherical.Due to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.
基金supported by China Agriculture Research System of MOF and MARA(CARS-41)Wens Fifth Five R&D Major Project(WENS-2020-1-ZDZX-007)。
文摘The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.
文摘Shimmy can reduce the service life of the nose landing gear, affect ride comfort, and even cause fuselage damage leading to aircraft crashes. Taking a light aircraft as the research object, the torsional freedom of landing gear around strut axis and lateral deformation of tire are considered. Since the landing gear shimmy is a nonlinear system, a nonlinear mechanical model of the front landing gear shimmy is established. Sobol index method is proposed to analyze the influence of structural parameters on the stability region of the nose landing gear, and Routh-Huritz criterion is used to verify the reliability of the analysis results of Sobol index method. We analyse the effect of torsional stiffness of strut, caster length, rated initial tire inflation pressure, rake angle, and vertical force on the stability region of theront landing gear. And the research shows that the optimization of the torsional stiffness of the strut and the caster length of the nose landing gear should be emphasized, and the influence of vertical force on the stability region of the nose landing gear should be paid attention to.
文摘目的:探讨在(疾病)诊断相关分类(diagnosis related groups,DRGs)形势下,腹腔镜结直肠癌经自然腔道取标本(NOSES)手术方式改进及其可行性。方法:回顾性分析安阳市肿瘤医院2019年2月至2021年2月实施DRGs的42例改进后的腹腔镜结直肠癌NOSES术,并与同期进行常规腹腔镜结直肠癌手术的238例患者在费用、治疗结果、并发症等方面相比较。结果:NOSES改进组42例患者DRGs控费成功率为95.2%(40/42),与常规腹腔镜组在DRGs费用及近期并发症发生率方面无显著性差异(P>0.05)。结论:腹腔镜结直肠癌NOSES改进手术可以达到DRGs费用标准,手术安全可靠,应用双7号丝线代替部分直线切割闭合器是可行的。
基金support from the National Key R&D Program of China (2019YFD0901903)the Innovation Team Project of Hebei (Province) Modern Agricultural Industry Technology System (HBCT2018170207)the Postgraduate Research & Practice Innovation Program of Jiangsu Province (SJCX20_1426)
文摘Traditionally fermented shrimp paste has a long fermentation period and is susceptible of external factors,which leads to unstable quality and limits its development and application.Therefore,the purpose of this study is to analyze the flavor changes in the shrimp paste fermentation process and screen out the key volatile aroma components in the shrimp paste to control the flavor quality of the shrimp paste products.The overall odor profile was detected by the electronic nose.A total of 106 volatile flavor compounds in the shrimp paste samples at different fermentation stages were identified by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)and headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS).The main aroma components alcohols,aldehydes,pyrazines and other substances in the fermentation process showed an overall upward trend.A total of 17 key volatile aroma components in shrimp paste at different fermentation stages were identified by the relative aroma activity value(ROAV)method.The combination of electronic nose,SPME-GC-MS and HS-GC-IMS could comprehensively reflect the changes of volatile components in shrimp paste at different fermentation stages,which helps to further understand the mechanism of shrimp paste flavor formation and provides a basis for the regulation of the flavor quality of shrimp paste products.
基金supported by the Key Clinical Projects of Peking University Third Hospital(grant no.BYSYZD2019013)。
文摘Background:This study aimed to review treatments and evaluate the aesthetic outcomes,complications,and reoperation rates regarding surgical correction for a postoperative contracted nose.Methods:PubMed,MEDLINE,and Embase databases were searched for studies detailing aesthetic outcomes and complications of surgical correction of a contracted nose.Surgical procedures,adjuvant treatment,outcomes,and complications were synthesized and analyzed.Results:Nine articles encompassing 376 patients were included in the systematic review,and six articles(198 participants)were included in the meta-analysis.The most frequently used graft material was the autologous rib cartilage(61.1%).Surgical procedures were heterogeneous in these studies.The nasolabial angle reduced by 9.52°(95%confidence interval(CI):(-11.95,-7.09),P<0.0001),and the nasal length increased significantly(standardized mean difference(SMD)=2.25,95%CI:(1.26,2.23),P<0.00001).However,the evidence was insufficient to determine a significant change in the columellar-labial angle(SMD=-0.95,95%CI:(-2.19,0.29),P=0.13)and columellar-lobular angle(SMD=2.39,95%CI:(-1.20,5.97),P=0.19).Aesthetic dissatisfaction(12.5%)and infection(4.5%)were the most commonly reported complications.Reoperation was performed in 5.3%of patients.Conclusion:Surgical correction can increase the nasal length,reduce the nasolabial angle,and have a low reoperation rate.No significant improvement in the columellar-labial or columellar-lobular angle was observed.
文摘Introduction: Acute mastoiditis is the most common complication of Acute Otitis Media (AOM) and it’s the cause of serious morbidity. There is no standard universally agreed-upon management approach to acute mastoiditis. This study aims to view the clinical presentation and management approaches in Khartoum Ear, Nose and Throat Hospital. Methodology: This is a prospective case series and a hospital-based study conducted at Khartoum Ear, Nose and Throat Hospital during the period from November 2017 to November 2019. A total of 61 patients were included in the study. Results: The median age at presentation is 5 years old, males are more affected than females with a ratio of 1.35:1, and the mean duration of symptoms prior to hospital admission was 9.6 days. The most common presenting symptoms were otalgia (83.3%), ear discharge (83.3%) and post-auricular swelling (83.3%), and the most common signs at admission were tenderness over the mastoid (95.1%), retroauricular swelling and protrusion of the auricle (82%), and redness over the mastoid (77%). The abnormal tympanic membrane was found in all patients with central perforation being the commonest finding (73.8%), and bulging tympanic membrane (21.3%). 34.4% of patients received oral antibiotics before admission and the mean duration of symptoms prior to admission increased significantly in those who received antibiotics 12.7 days in comparison to those who didn’t 8.3 days. Only 52.5% of patients had a past history of recurrent acute otitis media, and 8.2% had a past history of acute mastoiditis. All the patients with recurrent mastoiditis had a past history of recurrent acute otitis media. Computed Tomography (CT) scans were obtained for 50.8% and 83.9% of those scans showed coalescent mastoiditis. Further evidence of intracranial extension was found in 6.5% and Magnetic Resonance Imaging (MRI) was obtained for them. Of the study group, 67.2% presented with subperiosteal abscess, 4.9% with facial nerve palsy and 3.3% with brain abscess. Thirteen patients with no complications were managed initially with injectable and topical antibiotics and were successful in only 6 of them (46%), abscess incisions and drainages were needed in 46 patients and were successful in 34 of them (73.9%). Eighteen patients (29.5%) needed mastoidectomy and all of them were managed successfully (100%). One patient (1.6%) was referred for intracranial abscess drainage in a specialized hospital, also one patient (1.6%) initially presented with intracranial abscess died on the second day of admission and 96.8% were discharged in good condition. The mean duration of hospital stay was 7.5 days. Conclusion: Patients present to the hospital after a prolonged period with a higher rate of complications, and the delayed presentation increased significantly in patients who received oral antibiotics prior to admission. Conservative medical treatment in non-complicated acute mastoiditis was ineffective in more than half of the patients and abscess incision and drainage and/or mastoidectomy are often necessary for the management.
