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Impacts of waveforms on the fluid flow, wall shear stress, and flow distribution in cerebral aneurysms and the development of a universal reduced pressure

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Journal of Biom.d.cal Science and Engineering 2014年第1期7卷 7-14页

作者： Noel m. Naughton Brian d. Plourde John R. Stark Simona Hodis John P. Abraham department of Radiology Mayo Clinic Rochester USA School of Engineering University of St. Thomas St. Paul USA

The hydrodynamics of aneurysm blood flow is thought to be a critical factor in the evolution and potential rupture of blood vessel walls. The ability to predict which aneurysms may grow or rupture has eluded researchers and practicing clinicians. On the other hand, it is expected that local flow patterns, pressures, and wall shear stress play a role in the aneurysm life. In this study, the impact of waveform on these parameters was studied. A baseline waveform, taken from a patient, was applied to an aneurysm geometry. Then the waveform was m.d.fied by increasing and decreasing both the flowrates and the cardiac rate. In total, seven cases were investigated. It was found that there were remarkable similarities in the patterns of flow and wall stresses for the cases. These similarities existed throughout the cardiac cycle. It was also found that there was a reduced pressure variable that provides a universal relationship that characterizes all of the cases. It was seen that the maximum wall shear occurs at the neck of the aneurysm and scales with the peak systolic velocity. Finally, it is shown that the flow distribution to the multiple outlets does not appreciably depend on the details of the inlet waveform. All cases had a flow distribution that was within 2%.

关键词： Aneurysm Hem.d.namics Blood Flow Computational Fluid dynamics

dynamic Flexural m.d.lus and Low-Velocity Impact Response of Supercomposite<sup>Tm</sup>Laminates with Vertical Z-Axis milled Carbon Fiber Reinforcement

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materials Sciences and Applications 2021年第4期12卷 152-170页

作者： Suman Babu Ukyam Raju P. mantena damian L. Stoddard Arunachalam m. Rajendran Robert d. moser department of mechanical Engineering University of Mississippi Mississippi USA materials—US Army ERdC GSL Vicksburg Mississippi USA

In work reported here, the dynamic properties and low-velocity impact response of woven carbon/epoxy laminates incorporating a novel 3d interlaminar reinforcement concept with dense layers of Z-axis oriented milled ca... 详细信息

In work reported here, the dynamic properties and low-velocity impact response of woven carbon/epoxy laminates incorporating a novel 3D interlaminar reinforcement concept with dense layers of Z-axis oriented milled carbon fiber SupercompositeTM prepregs, are presented. Impulse-frequency response vibration technique is used for non-destructive evaluation of the dynamic flexural modulus (stiffness) and loss factor (intrinsic damping) of woven carbon/epoxy control and SupercompositeTM laminates. Low-velocity punch-shear tests were performed on control and SupercompositeTM laminates according to ASTM D3763 Standard using a drop-weight impact test system. Control panels had all layers of 3K plain woven carbon/epoxy prepregs, with a dense interlaminar reinforcement of milled carbon fibers in Z- direction used in designing the SupercompositeTM laminate—both having same areal density. Impulse-frequency response vibration experiments show that with a 50% replacement of woven carbon fabric in control panel with milled carbon fibers in Z direction dynamic flexural modulus reduced 25% - 30% (loss in stiffness) and damping increased by about the same 25% - mily:Verdana;">

关键词： SupercompositeTm damping Ratio dynamic Flexural m.d.lus milled Carbon Fibers Low-Velocity Punch-Shear

The Contribution of the Xpert^® mTB/RIF Assay to the Surveillance of drug-Resistant Tuberculosis in the Central African Republic

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Journal of Tuberculosis Research 2023年第1期11卷 23-32页

作者： Alain Farra Lydie V. danebera Gilles Ngaya Brice m. Yambiyo Alexandre manirakiza Christian d. mossoro-Kpinde National Reference Laboratory for Tuberculosis Institut Pasteur of Bangui Bangui Central African Republic Faculty of Health Sciences University of Bangui Bangui Central African Republic m.d.cal Laboratory Institute Pasteur of Bangui Bangui Central African Republic Epidemiology Unit Institute Pasteur of Bangui Bangui Central African Republic

Introduction: The Central African Republic is one of the 30 high Tuberculosis burden countries in the world, with an incidence of 540 cases per 100,000 population and a mortality of 91 deaths per 100,000 population. Since 2020, following WHO recommendations, the National Reference Laboratory for Tuberculosis has been using the Xpert® mTB/RIF assay as a first-line diagnostic test for the early detection of drug Resistance Tuberculosis. The goal of this study was to evaluate the contribution of the Xpert® mTB/RIF assay to the surveillance of rifampicin resistance in new and previously treated tuberculosis cases. materials and methods: The data relative to the Xpert® mTB/RIF assay carried out on various categories of tuberculosis patients registered at the National Reference Laboratory for Tuberculosis in 2020 were analyzed retrospectively. The categories of tuberculosis patients were new cases, failed treatment cases, relapse cases, lost-to-follow-up cases and multidrug-resistant tuberculosis contact cases. Results: A total of 1404 tuberculosis patients were registered at the NRL-TB in 2020;the mean age was 39.2 years (2 - 90 years) and the male-to-female sex ratio was 1.16:1. Overall, 32.7% (454/1404) proved infected with tuberculosis, of which 22.5% (102/454) cases showed resistance to rifampicin. The primary resistance rate was 9.1% (27/298) and the secondary resistance rate was 46.6% (75/161). Treatment failures and relapsed cases were significantly associated with rifampicin resistance (p 0.005). Conclusion: Large-scale use of Xpert® mTB/RIF, especially in the provinces of the Central African Republic, will help the ministry of Health to better control drug Resistance Tuberculosis in the country.

关键词： Xpert® mTB/RIF Assay Rifampicin Surveillance CAR

China under Uncertainty： Outlook, Counterfactual and Policy Simulations, and Reform Implementation--A Summary of Annual Report （2016-2017）

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2017年第2期12卷 167-187页

作者： Kevin X. d. Huang Guoqiang Tian Yibo Yang department of Economics Vanderbilt University Nashville TN 37235 USA Institute for Advanced Research Shanghai University of Finance and Economics Shanghai 200433 China School of Economics and Institute for Advanced Research Shanghai University of Finance and Economics Shanghai 200433 China department of Economics Texas A&M University College Station TX 77843-1372 USA

China＇s macroeconomy is surrounded by increased uncertainties while facing persistent downward pressures entering year 2017. major external challenges are imposed by the chaotic political climate and disorderly retreat from globalization of the US accompanied with the impending FEd rate hikes, which may trigger a destructive trade war and exert pressures on RmB depreciation and capital flight. Remaining ingrained in major internal challenges are the gridlock risks accumulated from excessive financialization of real estate sector and swelling housing market bubbles am.d.escalating debt levels, and more fundamentally, the continued off-real-to-virtual movement in the general economy and ascendancy of government over market in resource *** on IAR-Cmm m.d.l, which takes into account both cyclical and secular factors, the baseline real GdP growth rate is projected to be 6.5% in 2017 （6.13% using more reliable instead of official data）. Counterfactual analyses and policy simulations are also conducted to highlight the convoluted uncertainties surrounding China＇s macroeconomy. Through the lens of these analyses, we identify a root cause of the weak outlook as the persistently distorted economic structure due to procrastination in reforms of the institutions and governance, which not only impairs China＇s growth potential but also limits the power of its recent stimulating policies while exacerbating their side effects. Key to successful economic restructuring in the face of adversely evolving demographics are market-oriented reforms, with well-designed strategies to balance short-term stabilization and long-run development. Such reforms should hold center stage in China＇s transition towards a m.d.rn free market economy and regulatory state.

关键词： macroeconomic outlook uncertainty alternative scenarios policysimulation reform development governance

2nd Far Eastern Conference on m.d.cal and Biological Engineering,1993

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Chinese Journal of Biom.d.cal Engineering(English Edition) 1993年第2期2卷 47-49页

作者： Fangzhou Gu Ph.d.Honorary President of 2nd FECmBE Beijing,China Zibin Yang m.d.President of 2nd FECmBE Beijing,China

ForewordIt is our honor and pleasure to welcome you to the 2nd Far Eastern Conference on m.d.caland Biological Engineering (2nd FECmBE) in Beijing,China,*** 1987,Far Eastern Society of Biom.d.cal Engineering(China,Jap... 详细信息

关键词： Far affiliated welcome honor pleasure Eastern behalf mankind Australia Finland

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榴辉岩相剪切带是地壳深部的反映

地震地质译丛 1995年第3期17卷 59-64页

作者： d.m.Fountain 沈稿

1.引言在增厚的大陆地壳底部附近或大陆下的地幔中,榴辉岩的形成是地质界和地球物理界日益兴趣的一种过程。当碰撞造山运动,如阿尔卑斯造山运动时,大陆地壳某些部分受迫进入地幔,这时地壳物质会转变为榴辉岩。Laubscher(1990)列举了熟... 详细信息

1.引言在增厚的大陆地壳底部附近或大陆下的地幔中,榴辉岩的形成是地质界和地球物理界日益兴趣的一种过程。当碰撞造山运动,如阿尔卑斯造山运动时,大陆地壳某些部分受迫进入地幔,这时地壳物质会转变为榴辉岩。Laubscher(1990)列举了熟知的阿尔卑斯显生宙造山带、加里东褶皱带的大陆地壳中产生的榴辉岩。其他人推测,从各种理由上说,大陆下地壳及其下伏的地幔岩石圈,是由下地壳分层出并沉入地幔中的。在这两种情况下。

关键词：榴辉岩岩相剪切带地壳深部

management of Pediatric Abdominal Surgical Emergencies in Northern Benin

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Open Journal of Pediatrics 2020年第2期10卷 314-319页

作者： m. G. Yassegoungbe B. Tamou Sambo d. m. Seto m. A. Hodonou S. B. Noukpozounkou B. R. Assan S. A. Allode Pediatric Surgery National Teaching Hospital Hubert Koutoukou Maga Cotonou Benin General Surgery Teaching Hospital of Parakou Parakou Benin University Clinic of Visceral Surgery National Teaching Hospital Hubert Koutoukou Maga Cotonou Benin

Background: Pediatric abdominal surgical emergencies are major causes of morbidity and mortality. The goal was to identify the main determinants of their management and access to assess their evolution. Patients and methods: This is a prospective, descriptive and analytical study performed at Parakou teaching hospital and Tanguieta district hospital. It has been conducted from January 1st to July 31st 2016. All children were included aged 0 to 15 years and admitted for an abdominal surgical emergency with a Clinical Classification of Emergency Patients listed from 3 to 5. Results: Pediatric abdominal surgical emergencies accounted for 42.8% of pediatric surgical emergencies. The average age was 9.3 ± 3.5 years old. The sex ratio was 1.7. The most encountered etiologies were peritonitis (36.76%), abdominal trauma (16.17%) and anorectal malformations (14.71%). The comparison of the delay in operative treatment with the World Society of Emergency Surgery shows a delay in 82.35% of cases. Mortality was high preoperatively and was related to the neonatal period (p = 0.027) and to a resuscitation length of stay higher than 36 hours (p = 0.035). Conclusion: Surgical care was delayed, mainly due to the lack of technical capacities. Morbidity and mortality were relatively low.

关键词： Abdominal Surgical Emergency Pediatrics Peritonitis delay in Surgery

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频率域约束条件下的最小熵反褶积

石油物探译丛 1995年第1期 10-18页

作者： m.d.Sacchi 戴成泰

这里提出一种运用最小熵准则重新建立反射系数谱的方法。此种算法(Fm.d.可与传统的最小熵反褶积(m.d.以及线性规划(LP)、自回归(AR)方法相比较,就与地震道反褶积的线性算子的系数而言,m.d.法是通过使一个熵达到极大来进行。通过比较,... 详细信息

这里提出一种运用最小熵准则重新建立反射系数谱的方法。此种算法(Fm.d.可与传统的最小熵反褶积(m.d.以及线性规划(LP)、自回归(AR)方法相比较,就与地震道反褶积的线性算子的系数而言,m.d.法是通过使一个熵达到极大来进行。通过比较,这里提出的算法可使与反射系数系列谱的频率损失有关的范数达到极大。此方法可简化为一种非线性算法,即能进行有限频带数据的反褶积,避免了线性算子的固有限制。这里提出的方法通过各种合成例子来说明。为检查此种算法的正确性,还运用了野外数据。结果表明,此种方法是处理有限频带数据行之有效的方式。 Fm.d.LP方法的原理相类似。在频率约束条件下,这两种方法都是寻找一个特殊范数的极值。在LP方法中,线性规划问题采用了十分昂贵的单纯形法来解决。Fm.d.在每次迭代中仅用了两次快速富氏变换,减少了反演计算成本。

关键词：最小熵反褶积频率域约束地震勘探反射波

Torsional postbuckling characteristics of functionally graded graphene enhanced laminated truncated conical shell with temperature dependent material properties

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Theoretical & Applied mechanics Letters 2023年第4期13卷 272-279页

作者： Ham.d.m.Hasan Saad S.Alkhfaji Sattar A.mutlag department of mechanical Engineering University of AnbarRamadi 31001Iraq department of m.d.cal Instrumentation Engineering Ashur University CollegeBaghdad 10044Iraq

Buckling and postbuckling characteristics of laminated graphene-enhanced composite(GEC)truncated conical shells exposed to torsion under temperature conditions using finite element method(FEm)simulation are presented in this *** the thickness direction,the GEC layers of the conical shell are ordered in a piece-wise arrangement of functionally graded(FG)distribution,with each layer containing a variable volume fraction for graphene *** calculate the properties of temperaturedependent material of GEC layers,the extended Halpin-Tsai micromechanical framework is *** FEm m.d.l is verified via comparing the current results obtained with the theoretical estimates for homogeneous,laminated cylindrical,and conical shells,the FEm m.d.l is *** computational results show that a piece-wise FG graphene volume fraction distribution can improve the torque of critical buckling and torsional postbuckling ***,the geometric parameters have a critical impact on the stability of the conical ***,a temperature rise can reduce the crucial torsional buckling torque as well as the GEC laminated truncated conical shell’s postbuckling strength.

关键词： Torsional postbuckling Graphene enhanced composite Functionally graded graphene Finite element method Conical shell