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Otitis media with effusion in children: Pathophysiology, diagnosis, and treatment.A review

Journal of Otology 2019年第2期14卷 33-39页

作者： Pauline Vanneste Cyril Page Department of Otorhinolaryngology and Head & Neck Surgery Amiens University Hospital

Otitis media with effusion(OME)is a frequent paediatric disorder.The condition is often asymptomatic,and so can easily be missed.However,OME can lead to hearing loss that impairs the child's language and behavioural development.The diagnosis is essentially clinical,and is based on otoscopy and(in some cases)tympanometry.Nasal endoscopy is only indicated in cases of unilateral OME or when obstructive adenoid hypertrophy is suspected.Otitis media with effusion is defined as the observation of middle-ear effusion at consultations three months apart.Hearing must be evaluated(using an age-appropriate audiometry technique)before and after treatment,so as not to miss another underlying cause of deafness(e.***.perception deafness).Craniofacial dysmorphism,respiratory allergy and gastro-oesophageal reflux all favour the development of OME.Although a certain number of medications(antibiotics,corticoids,antihistamines,mucokinetic agents,and nasal decongestants)can be used to treat OME,they are not reliably effective and rarely provide long-term relief.The benchmark treatment for OME is placement of tympanostomy tubes(TTs)and(in some cases)adjunct adenoidectomy.The TTs rapidly normalize hearing and effectively prevent the development of cholesteatoma in the middle ear.In contrast,TTs do not prevent progression towards tympanic atrophy or a retraction pocket.Adenoidectomy enhances the effectiveness of TTs.In children with adenoid hypertrophy,adenoidectomy is indicated before the age of 4 but can be performed later when OME is identified by nasal endoscopy.Children must be followed up until OME has disappeared completely,so that any complications are not missed.

关键词： Otitis media with effusion Tympanostomy tube Ventilation tube Grommet Child

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Plastic wrinkling model and characteristics of shear enforced Ti-alloy thin-walled tubes under combination die constraints and differential temperature fields

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Chinese Journal of Aeronautics 2016年第6期29卷 1815-1829页

作者： Yan Jing Aeronautical Key Laboratory for Plastic Forming Technology Beijing 100024China Beijing Key Laboratory of Digital Plastic Forming Technology and Equipment Beijing 100024China Beijing Aeronautical Manufacturing Technology Research Institute Beijing 100024China

Plastic wrinkling predictions and shear enforced wrinkling characteristics of Ti-alloy thin-walled tubes under combination die constraints have become key problems urgently in need of solutions in order to improve forming quality in their shear bending processes under differential temperature fields. To address this, a wrinkling wave function was developed by considering their shear bend deformation characteristics. Based on this wave function and the thin shell theory, an energy prediction model for this type of wrinkling was established. This model enables consideration of the effects of shear deformation zone ranges, material parameters, loading modes, and friction coefficients between tube and dies on the minimum wrinkling energy. tube wrinkling sensitive zones(WSZs) can be revealed by combining this wrinkling prediction model with a thermalmechanical coupled finite element model for simulating these bending processes. The reliability of this wrinkling prediction model was verified, and an investigation into the tube wrinkling characteristics was carried out based on the experimental conditions. This found that the WSZs are located on either a single side or both sides of the maximum shear stress zone. When the friction coefficients between the tube and the various dies coincide, the WSZs are located on both sides.The larger the value of the tube inner corner radius and/or the smaller the value of the outer cornerradius, the smaller the wrinkling probability. With an increase in the value of the moving die displacement, the wrinkling probability increases at first, and then decreases.

关键词： Combination die constraint Differential temperature field Energy method Finite element Shear bending Ti-alloy thin-walled tube Wrinkling

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Time amplifying techniques towards atomic time resolution

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Science China(Technological Sciences) 2009年第12期52卷 3425-3446页

作者： LI JingZhen Institute of Photonic Engineering,College of Electron Science&Technology,Shenzhen University,and Shenzhen Key Laboratory of Micro·Nano Photonic Information,Shenzhen 518060,China Institute of Photonic Engineering College of Electron Science & Technology Shenzhen University and Shenzhen Key Laboratory of Micro-Nano Photonic Information Shenzhen China

High speed imaging technology has opened applications in many fields,such as collision,detonating, high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,at the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10 8 ―5×10 9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10 7 ―10 14 fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polari- zation and wavelength,and even quantum properties of photon.In the cascaded system of electro- magnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

关键词： time amplification image converter tube imaging tubeless imaging ultra-high speed imaging extremely-high speed imaging holog- raphic coherent shutter optical acceleration

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Effect of 2,5-dimethylfuran addition on ignition delay times of n-heptane at high temperatures

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Frontiers in Energy 2019年第3期13卷 464-473页

作者： Zhenhua GAO Erjiang HU Zhaohua XU Geyuan YIN Zuohua HUANG State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China

The shock tube autoignition of 2,5-dimethylfuran (DMF)/n-heptane blends (DMF)/n-100%, by mole fraction) with equivalence ratios of 0.5, 1.0, and 2.0 over the temperature range of 1200-1800 K and pressures of 2.0 atm and 10.0 atm were investigated. A detailed blend chemical kinetic model resulting from the merging of validated kinetic models for the components of the fuel blends was developed. The experimental observations indicate that the ignition delay times nonlinearly increase with an increase in the DMF addition level. Chemical kinetic analysis including radical pool analysis and flux analysis were conducted to explain the DMF addition effects. The kinetic analysis shows that at lower DMF blending levels, the two fuels have negligible impacts on the consumption pathways of each other.As the DMF addition increases to relatively higher levels, the consumption path of n-heptane is significantly changed due to the competition of small radicals, which primarily leads to the nonlinear increase in the ignition delay times of DMF/n-heptane blends.

关键词： ignition delay time shock tube kinetic model 2,5-dimethylfuran (DMF) n-heptane

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Comparison of decompression tubes with metallic stents for the management of right-sided malignant colonic obstruction

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World Journal of Gastroenterology 2019年第16期25卷 1975-1985页

作者： Yoshiyuki Suzuki Konosuke Moritani Yuki Seo Takayuki Takahashi Department of Surgery Ashikaga Red Cross HospitalTochigi 326-0843Japan

BACKGROUND Emergency surgical resection is a standard treatment for right-sided malignant colonic obstruction; however, the procedure is associated with high rates of mortality and morbidity. Although a bridge to surgery can be created to obviate the need for emergency surgery, its effects on long-term outcomes and the most practical management strategies for right-sided malignant colonic obstruction remain unclear.AIM To determine the appropriate management approach for right-sided malignant colonic obstruction.METHODS Forty patients with right-sided malignant colonic obstruction who underwent curative resection from January 2007 to April 2017 were included in the study.We compared the perioperative and long-term outcomes of patients who received bridges to surgery established using decompression tubes and those created using self-expandable metallic stents(SEMS). The primary outcome was the overall survival duration(OS) and the secondary endpoints were the diseasefree survival(DFS) duration and the preoperative and postoperative morbidity rates. Analysis was performed on an intention-to-treat basis.RESULTS There were 21 patients in the decompression tube group and 19 in the SEMS group. There were no significant differences in the perioperative morbidity rates of the two groups. The OS rate was significantly higher in the decompression tube group than in the SEMS group(5-year OS rate; decompression tube 79.5%,SEMS 32%, P = 0.043). Multivariate analysis revealed that the bridge to surgery using a decompression tube was significantly associated with the OS(hazard ratio, 17.41; P = 0.004). The 3-year DFS rate was significantly higher in thedecompression tube group than in the SEMS group(68.9% vs 45.9%; log-rank test,P = 0.032). A propensity score–adjusted analysis also demonstrated that the prognosis was significantly better in the decompression tube group than in the SEMS group.CONCLUSION The bridge to surgery using trans-nasal and trans-anal decompression tubes for right-sided malignant colonic obstruction is saf

关键词： Right-sided colon cancer Large bowel obstruction Self-expandable metallic stent Trans-anal tube Trans-nasal tube

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Effect of Non-Equilibrium Condensation of Moist Air on Flow Field in Ludwieg tube

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Journal of Thermal Science 2002年第2期11卷 104-113页

作者： ShigeruMatsuo MasanoriTanaka ToshiakiSetoguchi Department of Mechanical Engineering Saga University Saga Japan

The time-dependent behavior of non-equilibrium condensation of moist air through a Ludwieg tube with a diaphragm downstream is investigated by using a computational fluid dynamics work. The two-dimensional, compressible, Navier-Stokes equations, fully coupled with the condensate droplet growth equations, are numerically solved by a third-order MUSCL type TVD finite-difference scheme with a second-order fractional time step. Baldwin-Lomax turbulence model is employed to close the governing equations. The present computations represent the experimental flows well. The results obtained show that for an initial relative humidity over 40 %, the periodic excursions of the condensation shock occurs in the Ludwieg tube, and the frequency increases with the initial relative humidity. It is also found that total pressure loss due to non-equilibrium condensation in the Ludwieg tube should not be ignored even for a very low initial relative humidity. Furthermore, the variations of condensation properties are also

关键词： Ludwieg tube compressible flow condensation shock wave periodic flow non-equilibrium condensation supersonic nozzle.

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An Experimental Study of Porous Surface tubes for Enhancement of Binary Liquid Mixture Pool Boiling Heat Transfer

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Chinese Journal of Chemical Engineering 1998年第4期6卷 77-82页

作者：朱冬生童子龙谭盈科 Research Institute of Chemical Engineering South China University of Technology Guangzhou 510641 China

Experiments have been conducted on the pool boiling of binary mixtures in JK tubeswith porous surface and ribbed channels,attempting to enhace the boiling heat transfer coefficientsinvolved.The binary mixtures used in this study are R113 and R11.The results show that the boilingfi1m heat transfer coefficients for the R113 and R11 binary mixtures in JK2 and JK1 tubes are 2—8tirnes and 2—5 times greater than those in smooth tubes respectively.Based on this experimentaldata and simple theoretical analysis,a correlation has been proposed to predict the boiling heattransfer coefficients for R113/R11 mixtures in a horizontal JK tube with a relative error of less than16%.

关键词： porous surface tube pool boiling heat transfer enhancement binary mixture

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Study on buffering performance of thin-walled metal tube with different angles

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Defence Technology（防务技术） 2018年第6期14卷 702-708页

作者： Qun Liu Wen-tao Wang Wen-feng Zhang Beijing Institute of Space Mechanics and Electricity BeijingChina

High frequency shock load is often generated during pyrotechnic device working, which is detrimental to spacecraft structures and electric devices. Therefore, it is valuable to reduce the shock load in pyrotechnic device design. Actually, there are several ways to decrease pyroshock loads, such as reduction of powder,installation of buffering structure, insulation of damageable devices, and so on. Considered assuring the function of pyrotechnic device and minimum of structure modification, shock absorbing structure is more propitious to be introduced in pyrotechnic device. In this paper, based on the method of thinwalled metal tube diameter-expanding, a thin-walled tube shock buffering structure was designed on a separate bolt. Built on the simplified structure of a separate bolt, the model of cone piston impacting thin-walled tube absorber was established, and the thin-walled tube shock absorbing characteristics and the relation between cone angles and absorber performance were analyzed. The results showed that the change of buffering force of thin-walled tube could be divided into four phases, and each phase was correspondent to the cone piston structure. In addition, as the cone angle increases, the max shock acceleration changes in the style of decrease-increase-decrease-increase, which is the result of coupled effects of cone piston max enter depth, buffering force and energy loss. In short, these results could establish the relationships between thin-walled tube absorbing performance and its structure, which is of significance to develop low-shock pyrotechnic device.

关键词： Pyroshock Shock absorbing Thin-walled metal tube

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Novel approach for analysis of deformation behavior of thin-walled tube in free hydro-bulging process

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中国有色金属学会会刊：英文版 2005年第S3期15卷 299-304页

作者：杨连发郭成 School of Mechanical Engineering Xi'an Jiaotong University Xi'an 710049 ChinaDepartment of Electronic Machinery and Traffic Engineering Guilin University of Electronic Technology Guilin 541004 China School of Mechanical Engineering Xi'an Jiaotong University Xi'an 710049 China

Based on the assumption that profile of thin walled tube in free hydro-bulging process is a quadratic curve and any point on the profile moves vertically to the profile, mathematical models were deduced for analyzing the deformation behavior. The critical pressure and the maximum bulge coefficient(height) at bursting can be determined based on the models, in which a shape factor a is introduced to tightly communicate the material property and geometric parameters to plastic deformation. Free hydro-bulging experiments of stainless steel and low carbon steel tubes were conducted to validate the models, and the experimental data indicate that the theoretical predictions are reliable and accurate. The results display that the profile, dependent on the material and geometric parameters, can be hyperbola, parabola, arc and ellipse or alternative among them; moreover, the forming pressure and forming limit are both closely connected with material and geometric parameters.

关键词： hydro-bulging thin-walled tube deformation forming pressure formability

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Torsion Instability of Anisotropic Cylindrical Tissues with Growth

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Acta Mechanica Solida Sinica 2019年第5期32卷 621-632页

作者： Sang Ye Si-Fan Yin Bo Li Xi-Qiao Feng Institute of Biomechanics and Medical Engineering AMLDepartment of Engineering MechanicsTsinghua UniversityBeijing 100084China

Growth shapes soft tissues not only through mass addition or volume expansion but also through deformation instabilities and consequent morphological evolution.In this paper,we probe the torsion instability of an anisotropically growing tube with fiber reinforcement,which mimics many tubular organs in animals or plants.We derive the Stroh formulation for the incremental boundary value problem and numerically solve it using the surface impedance method.A linear st ability analysis is conducted to investigate the critical condition for the onset of wrinkling.The thresholds of helical wrinkling are calculated in terms of growth ratio and external load.The effect of fibers on the critical state under axial stretching is examined.It is found that the tangential growth tends to enhance the critical torsion angle but has a weak influence on the critical longitudinal mode of wrinkling,which,however,can be remarkably affected by the axial growth.Our study can help understand the formation of helical morphologies in biological mat erials and provide cues for engineering desired st ruc tu res or devices.

关键词： Biological material tube Growth Instability Stroh formulation

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