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Calcar-guided short-stem total hip arthroplasty: Will it be the future standard? Review and perspectives

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World Journal of Orthopedics 2021年第8期12卷 534-547页

作者： karl Philipp Kutzner Department of Orthopaedic Surgery St Josefs Hospital WiesbadenGermanyWiesbaden 65189Germany Department of Hip Surgery Gelenkzentrum Rhein-MainWiesbaden 65183Germany Center of Orthopedics and Traumatology Johannes Gutenberg-University of MainzMainz 55131Germany

Short stems in total hip arthroplasty(THA)are becoming increasingly *** Germany,already 10.4%of all primary THAs are performed using a cementless short *** concept of modern,calcar-guided,short stems aims for an individualized reconstruction of the hip anatomy by following the calcar of the femoral neck,a bone-and soft-tissue-sparing implantation technique,and physiological *** stem design uses either metaphyseal fixation alone or additional diaphyseal anchoring,depending on the stem alignment and *** individualized anchorage types increase the potential indications for the safe use of a short *** design features may account for potential advantages of current short stem implants compared with earlier shortstem designs,particularly in cases of reduced bone quality or osteonecrosis of the femoral head and femoral neck *** implantation technique,however,requires distinct knowledge regarding the characteristics of varus and valgus positioning,with the potential for clinical consequences.A learning curve for surgeons new to this technique must be taken into *** contact with the distal lateral cortex appears to be crucial to provide sufficient primary stability,and the use of intraoperative imaging to identify“undersizing”is highly *** results of several national registries indicate that calcarguided short stems are among the most successful implants in terms of mid-term ***,long-term data remain *** review introduces the characteristics of calcar-guided short-stem THA and summarizes the current evidence.

关键词： Total hip arthroplasty Short stem Calcar-guided Classification Indications Anchorage Optimys

Non-invasive diagnosis of alcoholic liver disease

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World Journal of Gastroenterology 2014年第40期20卷 14626-14641页

作者： Sebastian Mueller Helmut karl Seitz Vanessa Rausch Department of Internal Medicine Salem Medical Center University of Heidelberg 69121 Heidelberg Germany Center for Alcohol Research University of Heidelberg 69121 Heidelberg Germany

Alcoholic liver disease(ALD)is the most common liver disease in the Western *** many reasons,it isunderestimated and *** early diagnosis is absolutely essential since it(1)helps to identify patients at genetic risk for ALD;(2)can trigger efficient abstinence namely in non-addicted patients;and(3)initiate screening programs to prevent life-threateningcomplications such as bleeding from varices,spontaneous bacterial peritonitis or hepatocellular *** two major end points of ALD are alcoholic liver cirrhosis and the rare and clinically-defined alcoholic hepatitis(AH).The prediction and early diagnosis of both entities is still insufficiently solved and usually relies on acombination of laboratory,clinical and imaging *** is not widely conceived that conventional screeningtools for ALD such as ultrasound imaging or routine laboratory testing can easily overlook ca.40%of manifest alcoholic liver ***-invasive methods such as transient elastography(Fibroscan),acoustic radiation force impulse imaging or shear wave elastography have significantly improved the early diagnosis of *** algorithms allow either the exclusion or the exact definition of advanced fibrosis stages in ca.95%of *** correct interpretation of liver stiffness requires a timely abdominal ultrasound and actual transaminase *** non-invasive methods such as controlled attenuation parameter,serum levels of M30 or M65,susceptometry or breath tests are under current evaluation to assess the degree of steatosis,apoptosis and iron overload in these *** biopsy still remains an important option to rule out comorbidities and to confirm the prognosis namely for patients with AH.

关键词： Alcoholic hepatitis Alcoholic steatohepatitis Alcoholic liver disease Non-invasive Liver stiffness Serum marker Steatosis

In Vitro transformation of LW13 rat liver epithelial cells

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Cell Research 1992年第2期2卷 139-152页

作者： karl LETNANSKY Shanghai Institute of Cell Biology Academia Sinica Shanghai China Institute of Applied and Experimental Oncology University of Vienna Vienna Austria

A rat liver epithelial cell line designated LW13 was es-tablished using a sequential sedimentation *** cellline retained many normal properties of liver epithelial cellsand showed some structural and functional features resem-bling those of liver parenchymal ***3 cells becamemalignant after the introduction of exogenous transformingEJ Ha ras *** produced by inoculation of thetransformed cells into baby rats contained areas of poorlydifferentiated hepatocellular *** situ hybridizationanalysis confirmed the random rather than specific integra-tion of exogenous ras gene into host ***-more,an at least tenfold increase in the expression of theendogenous c myc gene was detected among transformedcell lines,suggesting the involvement of the c myc protooncogene in the in vitro transformation of rat liver epithelialcells by EJ Ha ras oncogene.

关键词： LW13-cell line in vitro transformation EJ Ha ras integration c myc expression.

Effective depth-of-penetration range due to hardness variation for different lots of nominally identical target material

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Defence Technology（防务技术） 2016年第2期12卷 171-176页

作者： Patrick FRUEH Andreas HEINE karl Ernst WEBER Matthias WICKERT fraunhofer EMI Eckerstrasse 479104 FreiburgGermany

The effect of small variations of target hardness on the depth of penetration for nominally identical target material has not been addressed systematically in publications yet and is often neglected. An investigation of this issue for laboratory-scale long rod projectiles penetrating into semi-infinite rolled-homogeneous-armor steel targets was conducted. The tungsten-heavy-alloy penetrators were of length 90 mm and diameter6 mm. Five lots of armor steel with a nominal hardness range of 280–330 BHN provided material for the targets. The pursued approach consisted of hardness testing of the targets, in total 17 ballistic experiments at velocities in between 1250 m/s and 1780 m/s and data analysis.A linear regression analysis of penetration vs. hardness shows that a target hardness increase within the given range of 280–330 BHN may result in a reduction of penetration depth of about 5.8 mm at constant velocity. This is equal to a change of-12% at an impact velocity of 1250 m/s. A multiple linear regression analysis included also the influence of yaw angle and impact velocity. It shows that small yaw angles and slight variations of impact velocities provide a smaller variation of the semi-infinite penetration depths than a variation of target hardness within a typical specification span of 50 BHN. For such a span a change in penetration of approximately-4.8 mm due to hardness variation is found, whereas 1°of yaw angle or-10 m/s of velocity variation gives a change of about-1.0 mm respectively-0.9 mm. For the given example, the overwhelming part of the variation is to be attributed to hardness effects – 4.8 mm out of 5.8 mm(83%). For nominally identical target material the target hardness thus influences the ballistic test results more severely than the typical scatter in impact conditions.

关键词：硬度变化渗透深度靶材料一元线性回归分析多元线性回归分析地段穿透深度冲击速度

Distributed non-cooperative robust MPC based on reduced-order models

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Control Theory and Technology 2016年第1期14卷 11-20页

作者： Yushen LONG Shuai LIU Lihua XIE karl Henrik JOHANSSON School of Electrical and Electronic Engineering Nanyang Technological University 639798 Singapore ACCESS Linnaeus Center School of Electrical Engineering Royal Institute of Technology SE-100 44 Stockholm Sweden

In this paper, a non-cooperative distributed MPC algorithm based on reduced order model is proposed to stabilize large-scale systems. The large-scale system consists of a group of interconnected subsystems. Each subsystem can be partitioned into two parts： measurable part, whose states can be directly measured by sensors, and the unmeasurable part. In the online computation phase, only the measurable dynamics of the corresponding subsystem and neighbour-to-neighbour communication are necessary for the local controller design. Satisfaction of the state constraints and the practical stability are guaranteed while the complexity of the optimization problem is reduced. Numerical examples are given to show the effectiveness of this algorithm.

关键词： Model predictive control distributed control building energy efficiency

Fatigue of 0.55C-1.72Si Steel with Tempered Martensitic and Carbide-Free Bainitic Microstructures

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Acta Metallurgica Sinica(English Letters) 2014年第1期27卷 55-62页

作者： Alejandro Leiro Arash Roshan karl-Gustaf Sundin Esa Vuorinen Braham Prakash Department of Engineering Sciences and Mathematics Lule University of Technology

High-Si spring steel was heat treated in three different ways： Quenching and tempering at 460 ℃ to obtain a tempered martensite microstructure, and austempering at 300 and 350 ℃, respectively, to obtain two different carbide-free bainitic microstructures. In the steel austempered at 350 ℃, both the bainite lath thickness and retained austenite content were higher than those of the steel austempered at 300 ℃. Rotating-bending fatigue tests were done in order to evaluate the effect of each heat treatment on the high-cycle fatigue behavior of the steel. When the austempering temperature was 300 ℃, the endurance limit was increased by 25% despite a 5% reduction in tensile strength when compared with that of the quenched and tempered steel. The relationship between endurance limit [Rfat （50~）] and ultimate tensile strength （Rm） was higher for the austempered samples in comparison with that of the quenched and tempered material. Therefore, it is believed that the presence of retained austenite affects the relationship between endurance limit and tensile strength.

关键词： Steels Fatigue Carbide-free bainite TRIP effect

Compliant Mechanism Synthesis by Using Elastic Similitude

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Chinese Journal of Mechanical Engineering 2015年第4期28卷 769-775页

作者： HANKE Uwe HAMPEL Peter COMSA Andrei MODLER Niels MODLER karl-Heinz Institute of Solid Mechanics TU Dresden 01069 Dresden Germany Institute of Lightweight Engineering and Polymer Technology TU Dresden 01307 Dresden Germany

Compliant mechanisms have several advantages, especially smaller number of elements and therefore less movable joints. The flexural members furthermore allow an integration of special functions like balancing or locking. Especially fiber reinforced materials exhibit a wide range of function integration considering their compliance in passive as well active applications. To take advantage of compliant elements in applications a robust synthesis tool is needed. The synthesis based on topology optimization method or the pseudo rigid body approach leads to complex structures. Considering the use of fiber reinforced material a synthesis approach which leads to less complex structures is more suitable. For building up simple structures, with only one cantilever beam as compliant element（B） a graphical approach using the elastic similitude is the most efficient method. A step-by-step synthesis procedure is presented to synthesize compliant mechanisms with rotatory joints（R） and prismatic joints（P） to develop RRB/PRB- and RPB-linkages. Using the elastic similitude to implement these results into a graphical synthesis algorithm is the innovation part of this paper. It can be shown that this approach leads to a comfortable handling of beam elements during the synthesis, where the two free parameters can be directly coupled to scale and fix the orientation of the beam element. This advantage inherently shortens the development process. In giving an example the focus lies of the experimental approach, which also shows that the simple BERNOULLI beam model is valid and so the synthesis by using the elastic similitude. The method is presented and discussed by using an application for a cup holder mechanism made of fiber reinforced material.

关键词： Compliant mechanism synthesis elastic similitude

Design of an innovative multi-stage forming process for a complex aeronautical thin-walled part with very small radii

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Chinese Journal of Aeronautics 2018年第11期31卷 2165-2175页

作者： Yao WANG Lihui LANG Ehsan SHERKATGHANAD karl Brian NIELSEN Chun ZHANG School of Mechanical Engineering and Automation Beihang University Department of Materials and Production Aalborg University Tianjin Tianduan Press Co. LTD

In this paper, an aeronautical thin-walled part with a complex geometry which has several sharp bends and curvatures in different directions was investigated. This kind of part is difficult to be manufactured only in one stage. Therefore, an innovative multi-stage active hydroforming process assisted by the rigid forming method was designed. In addition, an optimized blank geometry is obtained. In fact, the main focused point of this paper is to propose a new small radius rounded corner forming technique and analyze the mechanism. Two kinds of forming modes of changing a big rounded corner into a small one, which are related to different tangential positions of the die in the process of calibration, are analyzed theoretically. Meanwhile, the stress and strain states of the deformation region are compared. The relationships between the minimum relative radii of rounded corners I and II in the first stage and the hydraulic pressure are calculated by the bending theory. Finally, the influences of the tensile-bulging effect and the interface condition of the double-layer sheet on the forming quality of the specimen are investigated. The achieved results can make a foundation for utilizing the proposed method in forming of thin-walled parts with very small radii.

关键词： Double-layer sheet Hydroforming Multi-stage forming Small rounded corner Tensile-bulging effect

Recycling of magnesium drive train components

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Science China(Technological Sciences) 2009年第1期52卷 148-154页

作者： Daniel FECHNER Carsten BLAWERT Norbert HORT karl Ulrich KAINER MagIC-Magnesium Innovation Centre GKSS Research Centre Max-Planck-Straβe 1

With the development of new heat resistant magnesium alloys, the automotive industry has introduced several parts to the drive train. The rising number of large magnesium components will result in a higher quantity of automotive post consumer scrap. It was the aim of this work to find a reasonable alloy system for the recycling of these magnesium drive train components. A matrix of potential recy-cling alloys based on the magnesium alloy AM50 was prepared via permanent mould casting. The materials were investigated via tensile testing, creep tests and salt spray tests. Three alloys were selected for processing via high pressure die casting and the tests were repeated on the new materials. A promising system for recycling has been isolated and will be investigated more deeply for the influence of impurities.

关键词： magnesium recycling end-of-life vehicles recycling alloy post consumer scrap