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Pelvic fractures in blunt trauma patients:A comparative study
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作者 Alexander A Fokin Joanna Wycech Knight +5 位作者 Madison E Tharp Kyler C Brinton Phoebe K Gallagher Justin Fengyuan Xie Russell D Weisz Ivan Puente 《World Journal of Orthopedics》 2024年第5期418-434,共17页
BACKGROUND Pelvic fractures(PF)with concomitant injuries are on the rise due to an increase of high-energy trauma.Increase of the elderly population with age related comorbidities further complicates the management.Ab... BACKGROUND Pelvic fractures(PF)with concomitant injuries are on the rise due to an increase of high-energy trauma.Increase of the elderly population with age related comorbidities further complicates the management.Abdominal organ injuries are kindred with PF due to the proximity to pelvic bones.Presence of contrast blush(CB)on computed tomography in patients with PF is considered a sign of active bleeding,however,its clinical significance and association with outcomes is debatable.AIM To analyze polytrauma patients with PF with a focus on the geriatric population,co-injuries and the value of contrast blush.METHODS This retrospective cohort study included 558 patients with PF admitted to level 1 trauma center(01/2017-01/2023).Analyzed variables included:Age,sex,mechanism of injury(MOI),injury severity score(ISS),Glasgow coma scale(GCS),abbreviated injury scale(AIS),co-injuries,transfusion requirements,pelvic angiography,embolization,laparotomy,orthopedic pelvic surgery,intensive care unit and hospital lengths of stay,discharge disposition and mortality.The study compared geriatric and non-geriatric patients,patients with and without CB and abdominal co-injuries.Propensity score matching was implemented in comparison groups.RESULTS PF comprised 4%of all trauma admissions.89 patients had CB.286(52%)patients had concomitant injuries including 93(17%)patients with abdominal co-injuries.Geriatric patients compared to non-geriatric had more falls as MOI,lower ISS and AIS pelvis,higher GCS,less abdominal co-injuries,similar CB and angio-embolization rates,less orthopedic pelvic surgeries,shorter lengths of stay and higher mortality.After propensity matching,orthopedic pelvic surgery rates remained lower(8%vs 19%,P<0.001),hospital length of stay shorter,and mortality higher(13%vs 4%,P<0.001)in geriatric patients.Out of 89 patients with CB,45(51%)were embolized.After propensity matching,patients with CB compared to without CB had more pelvic angiography(71%vs 12%,P<0.001),higher embolization rates(64%vs 22%,P=0.02)and comparable mortality.CONCLUSION Half of the patients with PF had concomitant co-injuries,including abdominal co-injuries in 17%.Similarly injured geriatric patients had higher mortality.Half of the patients with CB required an embolization. 展开更多
关键词 Pelvic fractures Geriatric trauma patients Abdominal co-injuries Contrast blush Contrast extravasation ANGIOEMBOLIZATION Polytrauma patients Surgical interventions Blunt trauma External and internal fixation for pelvic stabilization
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On the Kenney-Lau Approach to Internal Stability Evaluation of Soils 被引量:1
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作者 Hans Ronnqvist Peter Viklander 《Geomaterials》 2014年第4期129-140,共12页
A commonly used approach to evaluating the potential for internal instability in soils is that of Kenney and Lau. This method involves a shape analysis of the grain size curve over a length of the soil’s finer part. ... A commonly used approach to evaluating the potential for internal instability in soils is that of Kenney and Lau. This method involves a shape analysis of the grain size curve over a length of the soil’s finer part. A soil that is internally unstable has a particle size distribution with a finer fraction less than the coarser fraction;therefore, the coarser fraction makes up the primary fabric of the material. Thus, the fine-grained particles are loose (non-structural) in between fixed (structural) coarser grains, and these loose fine particles are permitted to migrate through the constrictions of the fabric of the coarser fraction. This paper discusses the evolution of the Kenney-Lau method and its boundary relations, and furthermore, a discussion on adaptations of the method, which touches on field experience and engineering practice, is given. 展开更多
关键词 Internal stability Internal Erosion Granular Soils FILTERS Kenney-Lau Method
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Applying Empirical Methods to Assess the Internal Stability of Embankment Dam Cores of Glacial Till
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作者 Hans Ronnqvist Peter Viklander 《Geomaterials》 2015年第1期1-18,共18页
This paper presents a database of glacial till gradations that are compiled from laboratory internal stability tests from the literature and from core soils of existing dams, some of which have experienced internal er... This paper presents a database of glacial till gradations that are compiled from laboratory internal stability tests from the literature and from core soils of existing dams, some of which have experienced internal erosion. The potential internal instability of these gradations is assessed using empirical methods. Two approaches of evaluation are used: the Kenney-Lau method, which analyzes the shape of the gradation curve;and the Burenkova method, which uses factors of uniformity of the slope of the gradation. Although they include some uncertainties in terms of soils with fines, these methods, which are primarily developed from laboratory studies of sand and gravels, are used in engineering practice to evaluate widely graded soils that include fines, such as glacial tills. This study evaluates the glacial till gradations of the database using these approaches and discusses their applicability and relative predictive success. This study indicates that both the Kenney-Lau method and the Burenkova method have merit, but a closer analysis indicates that the Kenney-Lau approach has relatively better predictive ability based on the glacial till gradations analyzed in this study. 展开更多
关键词 Internal stability Internal Erosion CORES Glacial Tills Embankment Dams
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Stability of Tokamak Equilibrium with Internal Transport Barrier against High n MHD Ballooning Mode
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作者 SHI Bingren QU Wenxiao DONG Jiaqi 《Southwestern Institute of Physics Annual Report》 2005年第1期121-124,共4页
Internal transport barriers (ITBs) are phenomena associated with improved confinement mode of tokamak plasmas. Within the region where the ITB locates, the plasma pressure has a large gradient while the magnetic she... Internal transport barriers (ITBs) are phenomena associated with improved confinement mode of tokamak plasmas. Within the region where the ITB locates, the plasma pressure has a large gradient while the magnetic shear s has a minimum so that within and near the ITB, the absolute value of the shear is very low. Physics involved is plentiful, from the macroscopic ( MHD ) stability, to the suppression of microscopic instabilities thought to be responsible for anomalous transport. The treatment of very low shear also poses some theoretical difficulties. 展开更多
关键词 Internal transport barrier Ballooning stability Low shear stabilizing channel
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Disturbance Attenuation State-Feedback Control for Uncertain Interconnected Systems 被引量:1
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作者 Chen Qi, Bai Jingfeng & Chen Yazhu Biomedical Instrument Institute, Shanghai Jiaotong University, Shanghai 200030, P. R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2002年第4期66-72,共7页
This paper studies the problem of robust H∞ control design for a class of uncertain interconnected systems via state feedback. This class of systems are described by a state space model, which contains unknown nonlin... This paper studies the problem of robust H∞ control design for a class of uncertain interconnected systems via state feedback. This class of systems are described by a state space model, which contains unknown nonlinear interaction and time-varying norm-bounded parametric uncertainties in state equation. Using the Riccati-equation-based approach we design state feedback control laws, which guarantee the decentralized stability with disturbance attenuation for the interconnected uncertain systems. A simple example of an interconnected uncertain linear system is presented to illustrate the results. 展开更多
关键词 Interconnected system State feedback Internal stability H~∞ control.
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ALMOST DISTURBANCE DECOUPLING FOR A CLASS OF MINIMUM-PHASE HIGHER-ORDER CASCADE NONLINEAR SYSTEMS
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作者 毕卫萍 慕小武 林澜 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第4期441-448,共8页
The problem of almost disturbance decoupling (ADD) with internal stability is discussed, for a class of high_order cascade nonlinear systems having zero dynamics. Using adding power integrator techniques, the ADD prob... The problem of almost disturbance decoupling (ADD) with internal stability is discussed, for a class of high_order cascade nonlinear systems having zero dynamics. Using adding power integrator techniques, the ADD problems via a smooth static state feedback is solved. 展开更多
关键词 almost disturbance decoupling internal stability nonlinear gain
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On the Existence, Uniqueness and Stability of Solutions for Semi-linear Generalized Elasticity Equation with General Damping Term
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作者 Abita RAHMOUNE 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2017年第11期1549-1564,共16页
In this paper, we consider a semi-linear generalized hyperbolic boundary value problem associated to the linear elastic equations with general damping term and nonlinearities of variable exponent type. Under suitable ... In this paper, we consider a semi-linear generalized hyperbolic boundary value problem associated to the linear elastic equations with general damping term and nonlinearities of variable exponent type. Under suitable conditions, local and global existence theorems are proved. The uniqueness of the solution have been gotten by eliminating some hypotheses that have been imposed by other authors for different particular problems. We show that any solution with nontrivial initial datum becomes stable. 展开更多
关键词 Generalized semi-linear elasticity equation nonlinear internal stabilization generalized Lebesgue space Sobolev spaces with variable exponents
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ROBUST H∞ CONTROL FOR UNCERTAIN NONLINEAR SYSTEMS 被引量:2
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作者 Weiping BI 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2007年第4期545-553,共9页
This paper studies the robust H∞ disturbance attenuation with internal stability for uncertain nonlinear control systems. By adding one power integrator technique, this paper designs a explicit smooth robust dynamic ... This paper studies the robust H∞ disturbance attenuation with internal stability for uncertain nonlinear control systems. By adding one power integrator technique, this paper designs a explicit smooth robust dynamic feedback law while rejecting the disturbance to any specified degree of accuracy. Further, the example and simulation results show the effectiveness of the proposed schemes. 展开更多
关键词 Internal stability robust dynamic feedback specified degree.
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A dynamic two-zone model of continuous fluidized bed layering granulation with internal product classification 被引量:1
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作者 C. Neugebauer S. Palis +3 位作者 A. Buck E. Tsotsas S. Heinrich A. Kienle 《Particuology》 SCIE EI CAS CSCD 2017年第2期8-14,共7页
A dynamic two-zone model is proposed to address the formation of granulation and drying zones in fluidized bed layering granulation processes with internal product classification. The model assumes a constant volume f... A dynamic two-zone model is proposed to address the formation of granulation and drying zones in fluidized bed layering granulation processes with internal product classification. The model assumes a constant volume for the granulation zone, but a variable overall volume for the fluidized bed to account for classified product removal. The model is used to study the effect of various process parameters on dynamics and process stability. Stability is shown to depend on the separation diameter of product removal and the flow rate of the injected liquid. A lower and upper range of separation diameters with stable process behavior are found. In an intermediate range instability in the form of self-sustained oscillations is observed. The lower stability boundary is in qualitative agreement with recent experimental observations (Schmidt, Bück, & Tsotsas, 2015); the upper boundary was reported in a theoretical paper by Vreman, Van Lare, and Hounslow (2009) based on a single zone model. 展开更多
关键词 Layering granulation Zone formation Internal product classification Population balance modeling stability analysis
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