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Biomechanical Effects of Tibial Stems with Different Structures on Human Knee Joint after Total Knee Arthroplasty: A Finite Element Analysis

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Journal of Bionic Engineering 2022年第1期19卷 197-208页

作者： Meng Zhang Kaiwen zhang He Gong Department of Engineering Mechanics Nanling CampusJilin UniversityChangchun130025China

Porous structure in orthopedic prosthesis may reduce micromotion and increase the service life of implants.The purposes of this study were to compare the influence of the tibial stems with solid and porous structures in Total Knee Arthroplasty(TKA)on knee joint and prostheses,and to improve the mechanical stability of the host bone by seeking favorable structure for the tibial stem.The Finite Element(FE)models of TKA knee with four different structures in the middle segment of the tibial stem(i.e.,solid,cubic,truncated cubic,and octahedral structures)were constructed.The distributions of von Mises stress in the knee joint,tibial prosthesis and proximal tibia,and the compressive stresses of the tibial prosthesis and ultra-high-molecular-weight polyethylene for the four FE models were analyzed.The results showed that the tibial stem filled with the octahedral structure has the best mechanical performance among the above four types of tibial stems.It could effectively reduce the stress concentration and stress shielding effects,and provide an improved mechanical environment for knee joint after TKA.This study would shed some lights on the design and fabrication of porous implants targeted to biomedical applications.

关键词： Total knee arthroplasty Tibial stem Porous structure Finite element analysis Mechanical performance

Flex Ethernet Technology and Application in 5G Mobile Transport Network

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China Communications 2021年第2期18卷 250-258页

作者： Meng Zhang Research Institute of Telecommunications Transmission(RITT) China Academy of Information Communications Technology(CAICT)MIITBeijing 100191China

With the advent of 5G era,the rise of cloud services,virtual reality/virtual reality(AR/VR),vehicle networking and other technologies has put forward new requirements for the bandwidth and delay of the bearer network.Traditional Ethernet technology cannot meet the new requirements very well.Flex Ethernet(FlexE)technology has emerged as the times require.This paper introduces the background,standardization process,functional principle,application mode and technical advantages of FlexE technology,and finally analyses its application prospects and shortcomings in 5G mobile transport network.

关键词： Flex Ethernet(FlexE) 5G mobile transport network network slicing

Vascular macrophages sense octanal and drive athero-inflammation

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Cellular & Molecular Immunology 2022年第10期19卷 1077-1078页

作者： Lei Qiao Meng Zhang Cheng zhang The Key Laboratory of Cardiovascular Remodeling and Function Research Chinese Ministry of EducationChinese National Health Commission and Chinese Academy of Medical SciencesThe State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineDepartment of CardiologyQilu HospitalCheeloo College of MedicineShandong UniversityJinanChina Cardiovascular Disease Research Center of Shandong First Medical University Central Hospital Affiliated to Shandong First Medical UniversityJinanChina

In a recent paper in Science,Orecchioni et al.identified the expression of olfactory receptor 2(OLFR2)and its human ortholog olfactory receptor 6A2(OR6A2)in vascular macrophages,which detects the compound octanal and activates the NLRP3 inflammasome,driving vascular inflammation and atherosclerosis progression[1].Their work provides new insights into the pathogenesis of atherosclerosis and suggests that inhibiting OR6A2 may represent a promising anti-inflammatory strategy to preventand treatat herosclerosis(Fig.1).

关键词： NLRP3 inflammation

Myelin-associated glycoprotein combined with chitin conduit inhibits painful neuroma formation after sciatic nerve transection

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Neural Regeneration Research 2022年第6期17卷 1343-1347页

作者： Wei Pi Ci Li Meng Zhang Wei zhang Pei-Xun zhang Department of Orthopedics and Trauma Peking University People’s HospitalPeking UniversityBeijingChina Key Laboratory of Trauma and Neural Regeneration Peking UniversityBeijingChina National Center for Trauma Medicine BeijingChina

Studies have shown that myelin-associated glycoprotein(MAG)can inhibit axon regeneration after nerve injury.However,the effects of MAG on neuroma formation after peripheral nerve injury remain poorly understood.In this study,local injection of MAG combined with nerve cap made of chitin conduit was used to intervene with the formation of painful neuroma after sciatic nerve transfection in rats.After 8 weeks of combined treatment,the autotomy behaviors were reduced in rats subjected to sciatic nerve transfection,the mRNA expression of nerve growth factor,a pain marker,in the proximal nerve stump was decreased,the density of regenerated axons was decreased,the thickness of the myelin sheath was increased,and the ratio of unmyelinated to myelinated axons was reduced.Moereover,the percentage of collagen fiber area and the percentage of fibrosis marker alpha-smooth muscle actin positive staining area in the proximal nerve stump were decreased.The combined treatment exhibited superior effects in these measures to chitin conduit treatment alone.These findings suggest that MAG combined with chitin conduit synergistically inhibits the formation of painful neuroma after sciatic nerve transection and alleviates neuropathic pain.This study was approved by the Animal Ethics Committee of Peking University People’s Hospital(approval No.2019PHE027)on December 5,2019.

关键词： autotomy axon chitin conduit fibrosis myelin-associated glycoprotein painful neuroma peripheral nerve regeneration

Yield sustainability of winter wheat under three limited-irrigation schemes based on a 28-year field experiment

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The Crop Journal 2022年第6期10卷 1774-1783页

作者： Yanmei Gao Meng Zhang Zhimin Wang Yinghua zhang College of Agronomy and Biotechnology China Agricultural UniversityBeijing 100193China School of Life Science Shanxi Normal UniversityTaiyuan 030031ShanxiChina Ministerial and Provincial Co-Innovation Centre for Endemic Crops Production with High-quality and Efficiency in Loess Plateau Shanxi Agricultural UniversityTaigu 030801ShanxiChina

Sustainable intensification is an agricultural development direction internationally.However,little is known about the yield sustainability of winter wheat(Triticum aestivum L.)under limited irrigation schemes on the North China Plain(NCP).A 28-year field experiment from 1991 to 2018 at Wuqiao Experimental Station was used to characterize long-term yield,evapotranspiration(ET),and water use efficiency(WUE)trends under three irrigation treatments(W1,irrigation just before sowing;W2,irrigation before sowing and at jointing stage;W3,irrigation before sowing,at jointing stage,and at anthesis).Yield gaps and the effects of genetic improvement,climate change,and climate variables on wheat yield and key phenological stages were estimated using the Agricultural Production Systems Simulator(APSIM)model.Grain yield and WUE of winter wheat increased during the 28 years under the three irrigation treatments,and the upward trend of WUE followed a saturation curve pattern.ET increased slightly.Simulation results showed that genetic improvement dramatically prolonged the phenological stages of vegetative growth period and contributed to yield increase by 0.03%-15.6%.The rapid increase in yield with lower water use was associated mainly with an increase in biomass with genetic improvement and partly with an increase in harvest index.A curvilinear relationship between WUE and yield emphasized the importance of obtaining high yields for high WUE.The yield gaps between potential yield and yield under W1 treatment increased from 1991 to 2018 but were relatively constant for the W2 and W3 treatments.Elevated atmospheric CO_(2) concentration offset the negative effects of temperature increase on yield,leading to minor(-2.3%to 0.3%)changes in yield under climate change.Thus,genetic improvement played a dominant role in yield increase,and limited-irrigation schemes(W2 and W3)can increase wheat yield and promote sustainability of crop production on the NCP.

关键词： Yield Sustainability Cultivars Climate change Phenology

An electroencephalography-based human-machine interface combined with contralateral C7 transfer in the treatment of brachial plexus injury

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Neural Regeneration Research 2022年第12期17卷 2600-2605页

作者： Meng Zhang Ci Li Song-Yang Liu Feng-Shi zhang Pei-Xun zhang Department of Orthopedics and Trauma Peking University People’s HospitalBeijingChina Key Laboratory of Trauma and Neural Regeneration Peking UniversityBeijingChina National Center for Trauma Medicine BeijingChina

Transferring the contralateral C7 nerve root to the median or radial nerve has become an important means of repairing brachial plexus nerve injury.However,outcomes have been disappointing.Electroencephalography(EEG)-based human-machine interfaces have achieved promising results in promoting neurological recovery by controlling a distal exoskeleton to perform functional limb exercises early after nerve injury,which maintains target muscle activity and promotes the neurological rehabilitation effect.This review summarizes the progress of research in EEG-based human-machine interface combined with contralateral C7 transfer repair of brachial plexus nerve injury.Nerve transfer may result in loss of nerve function in the donor area,so only nerves with minimal impact on the donor area,such as the C7 nerve,should be selected as the donor.Single tendon transfer does not fully restore optimal joint function,so multiple functions often need to be reestablished simultaneously.Compared with traditional manual rehabilitation,EEG-based human-machine interfaces have the potential to maximize patient initiative and promote nerve regeneration and cortical remodeling,which facilitates neurological recovery.In the early stages of brachial plexus injury treatment,the use of an EEG-based human-machine interface combined with contralateral C7 transfer can facilitate postoperative neurological recovery by making full use of the brain’s computational capabilities and actively controlling functional exercise with the aid of external machinery.It can also prevent disuse atrophy of muscles and target organs and maintain neuromuscular junction effectiveness.Promoting cortical remodeling is also particularly important for neurological recovery after contralateral C7 transfer.Future studies are needed to investigate the mechanism by which early movement delays neuromuscular junction damage and promotes cortical remodeling.Understanding this mechanism should help guide the development of neurological rehabilitation strategies for patients with

关键词： arm injuries brachial plexus brain-computer interfaces nerve transfer nerve regeneration nerve tissue neurofeedback neurological rehabilitation user-computer interface

Fundamental Trackability Problems for Iterative Learning Control

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自动化学报:英文版 2023年第10期10卷 1933-1950页

作者： Deyuan meng Jingyao zhang Seventh Research Division Beihang University(BUAA)Beijing 100191China School of Automation Science and Electrical Engineering Beihang University(BUAA)Beijing 100191China

Generally, the classic iterative learning control(ILC)methods focus on finding design conditions for repetitive systems to achieve the perfect tracking of any specified trajectory,whereas they ignore a fundamental problem of ILC: whether the specified trajectory is trackable, or equivalently, whether there exist some inputs for the repetitive systems under consideration to generate the specified trajectory? The current paper contributes to dealing with this problem. Not only is a concept of trackability introduced formally for any specified trajectory in ILC, but also some related trackability criteria are established. Further, the relation between the trackability and the perfect tracking tasks for ILC is bridged, based on which a new convergence analysis approach is developed for ILC by leveraging properties of a functional Cauchy sequence(FCS). Simulation examples are given to verify the effectiveness of the presented trackability criteria and FCS-induced convergence analysis method for ILC.

关键词： Convergence functional Cauchy sequence(FCS) iterative learning control(ILC) trackability

Nomogram for predicting disease-specific survival in osteosarcoma

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Chinese Medical Journal 2022年第9期135卷 1126-1128页

作者： Xia Yang Yajie Yang Xin Weng Meng Zhang Department of Pathology Sir Run Run Shaw hospital of Zhejiang UniversityZhejiang 310020China Department of Pathology Shenzhen Second People's HospitalShenzhenChina

To the Editor:Osteosarcoma(OS)is the most common malignant primary bone tumor majorly affecting children,adolescents,and young adults.Statistic studies showed that up to 20%of OS patients have clinically detectable metastatic tumor at presentation,and>85%of metastases occurs in the lung.Thus,identifying risk factors that reflect the biological characteristics and survival of OS could lead to better interventions for patients.

关键词： lung osteosarcoma patients

Optical remote sensing image characteristics of large amplitude convex mode-2 internal solitary waves:an experimental study

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Acta Oceanologica Sinica 2023年第6期42卷 16-23页

作者： Zhixin Li Meng Zhang Keda Liang Jing Wang College of Physics and Optoelectronic Engineering Ocean University of ChinaQingdao 266100China

A series of experiments are designed to propose a new method to study the characteristics of convex mode-2internal solitary waves(ISWs)in optical remote sensing images using a laboratory-based optical remote sensing simulation platform.The corresponding wave parameters of large-amplitude convex mode-2 ISWs under smooth surfaces are investigated along with the optical remote sensing characteristic parameters.The mode-2 ISWs in the experimentally obtained optical remote sensing image are produced by their overall modulation effect on the water surface,and the extreme points of the gray value of the profile curve of bright-dark stripes appear at the same location as the real optical remote sensing image.The present data extend to a larger range than previous studies,and for the characteristics of large amplitude convex mode-2 ISWs,the experimental results show a second-order dependence of wavelength on amplitude.There is a close relationship between optical remote sensing characteristic parameters and wave parameters of mode-2 ISWs,in which there is a positive linear relationship between the bright-dark spacing and wavelength and a nonlinear relationship with the amplitude,especially when the amplitude is very large,there is a significant increase in bright-dark spacing.

关键词： mode-2 internal solitary waves optical remote sensing characteristic parameter wave characteristic