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Effect of burden and origin sites of premature ventricular contractions on left ventricular function by 7-day Holter monitor 被引量:4
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作者 Wenhua Xu Mingfang Li +12 位作者 Minglong Chen Bing Yang Daowu Wang Xiangqing Kong Hongwu Chen Weizhu Ju Kai Gu Kejiang Cao Hailei Liu Qi Jiang Jiaojiao Shi Yan Cui Hong Wang 《The Journal of Biomedical Research》 CAS CSCD 2015年第6期465-474,共10页
Recent studies have shown that premature ventricular contractions (PVCs) could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due... Recent studies have shown that premature ventricular contractions (PVCs) could enlarge the heart, but its risk factors are incompletely understood as a single 24-hour recording cannot reflect the true PVC burden due to day-to-day variability. Our purpose was to investigate the effect of burden and origin sites on left ventricular (LV) function in patients with PVCs by 7-day Holter electrocardiography (ECG). From May 2012 to August 2013, 112 consecutive patients with PVCs were recruited from the authors' affiliated hospital. All patients received 2-dimensional transthoracic echocardiography, 12-lead routing ECG and 7-days Holter ECG. Serum N-terminal pro- brain natriuretic peptide (NT-proBNP) levels were measured. A total of 102 participants with PVCs were included in the final analysis. Origin of PVCs from the tricuspid annulus had the highest burden and NT-proBNP level. LV papillary muscle had a higher LV ejection fraction (EF) level and a lower LV end-systolic dimension (ESD) than other PVC foci (P〈0.05). The high burden group had a higher LV end-diastolic dimension (EDD) and LVESD but lower LVEF than the other two groups (P〈0.05). Female, older age, physical work, and history of PVCs had a significantly positive correlation with symptoms. Male, older age, physical work, and high burden were positive predictors of enlarged LVEDD, LVESD and higher serum NT-proBNP level, but lower LVEF. Seven-day dynamic ECG Holter monitor showed the true PVC burden on patients with PVCs. PVCs with a lower burden or origin from the LV papillary muscle and the fascicle were relatively benign, while PVCs with a higher burden or origin from the tricuspid annulus may lead to cardiac dysfunction. 展开更多
关键词 premature ventricular contractions BURDEN origin sites left ventricular function
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Functions and Translation of Nominalization in Business Contracts
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作者 Guifang Wang Shaolong Liu 《经济管理学刊(中英文版)》 2021年第1期46-52,共7页
Nominalization refers to the process of producing a noun from another part of speech or the derivation of a noun phrase from an underlying clause.In order to fulfill the specific analysis of nominalization in business... Nominalization refers to the process of producing a noun from another part of speech or the derivation of a noun phrase from an underlying clause.In order to fulfill the specific analysis of nominalization in business English contract,a corpus has been created with typical contracts.Based on a self-built business contract corpus,aspects of English nominalization,including its frequency of use,meaning selection and discourse position and function,have been examined.This study has found that nominalization is one of the most important characteristics of business contracts,and English nominalization can function mainly to improve the conciseness,formality,objectivity,and cohesiveness of the discourse.Meanwhile,the different characteristics of nominalization require different translation strategies and methods.The findings of this study may have implications for the business English teaching and translation. 展开更多
关键词 NOMINALIZATION Business contract function CORPUS
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Common Fixed Point Results for Quasi-contractions Involving Altering Distance Functions in Ordered Cone Metric Spaces 被引量:1
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作者 SONG Ji-ping WANG Mao-fa 《Chinese Quarterly Journal of Mathematics》 2018年第1期1-16,共16页
Some common fixed point results for mappings satisfying a quasi-contractive condition which involves altering distance functions are obtained in partially ordered complete cone metric spaces. A sufficient condition fo... Some common fixed point results for mappings satisfying a quasi-contractive condition which involves altering distance functions are obtained in partially ordered complete cone metric spaces. A sufficient condition for the uniqueness of common fixed point is proved. Also, an example is given to support our results. 展开更多
关键词 partially ordered cone metric space quasi-contraction common fixed point altering distance function
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SOME NEW ITERATED FUNCTION SYSTEMS CONSISTING OF GENERALIZED CONTRACTIVE MAPPINGS
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作者 Shaoyuan Xu Wangbin Xu Dingxing Zhong 《Analysis in Theory and Applications》 2012年第3期269-277,共9页
Iterated function systems (IFS) were introduced by Hutchinson in 1981 as a natural generalization of the well-known Banach contraction principle. In 2010, D. R. Sahu and A. Chakraborty introduced K-Iterated Function... Iterated function systems (IFS) were introduced by Hutchinson in 1981 as a natural generalization of the well-known Banach contraction principle. In 2010, D. R. Sahu and A. Chakraborty introduced K-Iterated Function System using Kannan mapping which would cover a larger range of mappings. In this paper, following Hutchinson, D. R. Sahu and A. Chakraborty, we present some new iterated function systems by using the so-called generalized contractive mappings, which will also cover a large range of mappings. Our purpose is to prove the existence and uniqueness of attractors for such class of iterated function systems by virtue of a Banach-like fixed point theorem concerning generalized contractive mappings. 展开更多
关键词 iterated function system ATTRACTOR generalized contractive mapping completemetric space fixed point
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GENERALIZED WARDOWSKI TYPE FIXED POINT THEOREMS VIA α-ADMISSIBLE FG-CONTRACTIONS IN b-METRIC SPACES 被引量:1
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作者 Vahid PARVANEH Nawab HUSSAIN Zoran KADELBURG 《Acta Mathematica Scientia》 SCIE CSCD 2016年第5期1445-1456,共12页
Recently, Wardowski [Fixed Point Theory Appl., 2012: 94, 2012] introduced and studied a new contraction called F-contraction to prove a fixed point result as a generalization of the Banach contraction principle. In th... Recently, Wardowski [Fixed Point Theory Appl., 2012: 94, 2012] introduced and studied a new contraction called F-contraction to prove a fixed point result as a generalization of the Banach contraction principle. In this paper, we introduce an α-β-FG-contraction and generalize the Wardowski fixed point result in b-metric and ordered b-metric spaces. As an application of our results we deduce Suzuki type fixed point results for β-FG-contractions.Moreover, we discuss some illustrative examples to highlight the realized improvements. 展开更多
关键词 α-admissible mapping F-contraction α-continuous function
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ELXED POINT THEOREM OF COMPOSITION g-CONTRACTION MAPPING AND ITS APPLICATIONS 被引量:1
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作者 YUN Tian-quan(云天铨) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第10期1132-1139,共8页
Any composition sequential mapping, periodic composition mapping of a complete non-empty metric space M into M with geometric mean contraction ratio less than 1 ( simplifying as 'g-contraction mapping' ) has a... Any composition sequential mapping, periodic composition mapping of a complete non-empty metric space M into M with geometric mean contraction ratio less than 1 ( simplifying as 'g-contraction mapping' ) has a unique fixed point in M . Applications of the theorem to the proof of existence and uniqueness of the solutions of a set of non-linear differential equations and a coupled integral equations of symmetric bending of shallow shell of revolution are given. 展开更多
关键词 contractION MAPPING g-contraction MAPPING BANACH contractION MAPPING THEOREM functional analysis differential EQUATION integral EQUATION SHALLOW shell
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Uniqueness of Common Fixed Points for a Family of Mappings with <i>Φ</i>-Contractive Condition in 2-Metric Spaces 被引量:9
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作者 Yong-Jie Piao 《Applied Mathematics》 2012年第1期73-77,共5页
In this paper, we will introduce a class of 5-dimensional functions Φ and prove that a family of self-mappings {Ti,j} iεN in 2-metric space have an unique common fixed point if 1) {Ti,j} iεN satisfies Φj-contracti... In this paper, we will introduce a class of 5-dimensional functions Φ and prove that a family of self-mappings {Ti,j} iεN in 2-metric space have an unique common fixed point if 1) {Ti,j} iεN satisfies Φj-contractive condition, where ΦjεΦ, for each jεN;2) Tm,μ n,v for all m,n,μ,vεN with μ ≠ v . Our main result generalizes and unifies many known unique common fixed point theorems in 2-metric spaces. 展开更多
关键词 2-Metric Space 5-Dimensional functions Φ Φ-contractive CONDITION CAUCHY Sequence Common Fixed Point
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COMMON FIXED POINT OF GENERALIZED WEAKLY CONTRACTIVE MAPS IN PARTIAL METRIC SPACES 被引量:5
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作者 Vesna COJBAIC RAJIC Stojan RADENOVIC Sunny CHAUHAN 《Acta Mathematica Scientia》 SCIE CSCD 2014年第4期1345-1356,共12页
In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized (ψ, Ф)-weak contractive conditions are obtained. Our results generalize, ext... In this paper, using the context of complete partial metric spaces, some common fixed point results of maps that satisfy the generalized (ψ, Ф)-weak contractive conditions are obtained. Our results generalize, extend, unify, enrich and complement many existing results in the literature. Example are given showing the validaty of our results. 展开更多
关键词 Common fixed point lower semi-continuous function weak (ψ Ф)-contraction partial metric space
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CARATHEODORY INEQUALITY FOR ANALYTIC OPERATOR FUNCTION
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作者 Yang Changsenof Math., Henan Normal Univ., Xinxiang 453002. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2001年第3期285-289,共5页
Suppose H is a complex Hilbert space, A H(Δ) denotes the set of all analytic operator functions on Δ, and the set N H(Δ)={f(z)|f(z) is an analytic operator function on the open uint disk Δ, f(z)f(w)=f(w)f(z),f... Suppose H is a complex Hilbert space, A H(Δ) denotes the set of all analytic operator functions on Δ, and the set N H(Δ)={f(z)|f(z) is an analytic operator function on the open uint disk Δ, f(z)f(w)=f(w)f(z),f *(z)f(z)=f(z)f *(z),z,w∈Δ}. The note proves that if f(z)∈N H(Δ),(or A H(Δ))‖f(z)‖≤1,z∈Δ then‖f′(T)‖≤(1-‖T‖ 2) -1 ‖I-f *(T)f(T)‖ 12 ‖I-f(T)f *(T)‖ 12 , where T∈L(H)(orT *T=TT *,respectively),‖T‖<1,Tf=fT. 展开更多
关键词 Analytic operator function proper contraction resolution of identity.
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MEAN VALUE OF ANALYTIC OPERATOR FUNCTIONS
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作者 喻小培 蹇明 《Acta Mathematica Scientia》 SCIE CSCD 1995年第4期468-473,共6页
In this paper, it is proved that if A is a normal proper contraction on Hilbert space H and F(z) = U(z) + iV(z) is operator-valued analytic on the unit disc Delta and 0 < p < 1, then parallel to F(A)parallel to(... In this paper, it is proved that if A is a normal proper contraction on Hilbert space H and F(z) = U(z) + iV(z) is operator-valued analytic on the unit disc Delta and 0 < p < 1, then parallel to F(A)parallel to(p) less than or equal to parallel to F(0)parallel to(p) + C-p (1 - parallel to A parallel to)(-2) [GRAPHICS] 展开更多
关键词 Hilbert space OPERATOR operator-valued function proper contraction
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A Family of Non-Self Maps Satisfying <i>Φ</i><sub>i</sub>-Contractive Condition and Having Unique Common Fixed Point in Metrically Convex Spaces 被引量:1
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作者 Yongjie Piao Dongzhe Piao 《Advances in Pure Mathematics》 2012年第4期280-284,共5页
Class of 5-dimensional functions Φ was introduced and a convergent sequence determined by non-self mappings satisfying certain Φi-contractive condition was constructed, and then that the limit of the sequence is the... Class of 5-dimensional functions Φ was introduced and a convergent sequence determined by non-self mappings satisfying certain Φi-contractive condition was constructed, and then that the limit of the sequence is the unique com-mon fixed point of the mappings was proved. Finally, several more general forms were given. Our main results gener-alize and unify many same type fixed point theorems in references. 展开更多
关键词 Metrically Convex Space 5-Dimensional functions Φ Φi-contractive CONDITION Common Fixed Point Complete
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Fixed Point Theorems of the Iterated Function Systems
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作者 Ji You-qing Liu Zhi Ri Song-il 《Communications in Mathematical Research》 CSCD 2016年第2期142-150,共9页
In this paper, we present some fixed point theorems of iterated function systems consisting of α-ψ-contractive type mappings in Fractal space constituted by the compact subset of metric space and iterated function s... In this paper, we present some fixed point theorems of iterated function systems consisting of α-ψ-contractive type mappings in Fractal space constituted by the compact subset of metric space and iterated function systems consisting of Banach contractive mappings in Fractal space constituted by the compact subset of generalized metric space, which is Mso extensively applied in topological dynamic system. 展开更多
关键词 fixed point α-ψ-contractive mapping iterated function system gener-alized metric space
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DIFFERENTIAL INEQUALITIES OF OPERATOR-VALUED ANALYTIC FUNCTIONS
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作者 蹇明 《Acta Mathematica Scientia》 SCIE CSCD 2001年第2期166-170,共5页
Some differential inequalities and integral inequalities for operator-valued an- alytic functions are investigated.
关键词 Proper contraction operator-valued analytic function differential inequality integral inequality
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具有状态时滞的Kirchhoff型吊桥方程解的渐近行为
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作者 王素萍 马巧珍 +1 位作者 齐渊 赵花妮 《兰州理工大学学报》 CAS 北大核心 2024年第6期157-163,共7页
考虑了具有状态依赖时滞Kirchhoff型吊桥方程解的渐近行为.应用Banach不动点定理得到了该方程存在局部唯一的温和解,运用压缩函数证明演化算子是渐近紧的,得到全局吸引子的存在性.
关键词 Kirchhoff型吊桥方程 状态时滞 压缩函数 全局吸引子
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川芎嗪抑制ROCK的表达降低模拟失重大鼠血管Ca^(2+)敏感性
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作者 王慧平 白晓镯 +4 位作者 赵晶 赵省心 刘朕印 党凯 高云芳 《西北大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第5期919-928,共10页
研究失重条件下血管平滑肌收缩性、Ca^(2+)敏感性及其调控通路RhoA-ROCK蛋白表达的变化,以及川芎嗪干预对其的影响。大鼠尾部悬吊模拟失重,在机体前、后部分别选取颈总动脉和肠系膜上动脉。在模拟失重大鼠颈总动脉中,由苯肾上腺素(PHE)... 研究失重条件下血管平滑肌收缩性、Ca^(2+)敏感性及其调控通路RhoA-ROCK蛋白表达的变化,以及川芎嗪干预对其的影响。大鼠尾部悬吊模拟失重,在机体前、后部分别选取颈总动脉和肠系膜上动脉。在模拟失重大鼠颈总动脉中,由苯肾上腺素(PHE)或KCl诱发的血管收缩性和Ca^(2+)敏感性增强,RhoA激酶2(ROCK II)的表达、肌球蛋白磷酸酶靶亚基1(MYPT1)和肌球蛋白调节轻链(MLC)的磷酸化水平均上升,血管孵育Y-27632(ROCK特异性抑制剂)后可降低以上变化。模拟失重大鼠灌饲川芎嗪亦可降低以上变化。模拟失重后,大鼠肠系膜上动脉的收缩性和Ca^(2+)敏感性、ROCK II的表达、MYPT1和MLC的磷酸化水平降低,血管孵育Y-27632对以上变化无明显作用。模拟失重大鼠灌饲川芎嗪亦对以上变化无明显作用。结果表明,由RhoA-ROCK调控的血管平滑肌Ca^(2+)敏感性的变化可能是失重条件下机体前后部血管收缩性发生区域性重塑的关键因素。川芎嗪可抑制ROCK蛋白的表达,降低血管平滑肌升高的Ca^(2+)敏感性,从而纠正失重条件下机体前部血管收缩性的增强,但对失重条件下机体后部血管收缩性的减弱无恢复作用。 展开更多
关键词 Ca^(2+)敏感性 RhoA-ROCK 血管收缩性 模拟失重 川芎嗪
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THE EXISTENCE AND UNIQUENESS OF SOLUTION FOR A CLASS OF STOCHASTIC FUNCTIONAL EQUAFIONS ON S.P.SPACE 被引量:10
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作者 刘坤会 秦明达 陆传赉 《Acta Mathematica Scientia》 SCIE CSCD 2001年第3期391-400,共10页
This paper is concerned with the existence and uniqueness of solution for a class of stochastic functional equation: X =φ(X), where φ: B → B and B is a Banach space consisted of all left-continuous, (■_t)-adapted ... This paper is concerned with the existence and uniqueness of solution for a class of stochastic functional equation: X =φ(X), where φ: B → B and B is a Banach space consisted of all left-continuous, (■_t)-adapted processes. Also, the main result is applied to some S.D.E (or S.I.E.). And the authors adopted some of the results in current research in the models of stochastic control recently. This paper proves the ekistence and uniquence and uniqueness of solution for stochastic functional equation. A series of corollaries are deduced from the special examples of the theorems in this paper. 展开更多
关键词 Stochastic functional equation stochastic differential (integral) equation principle of contraction mapping
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Mechanism of change in cardiac function after mitral valve replacement
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作者 钱伟 张宝仁 +4 位作者 朱家麟 陈如坤 郝家骅 蔡凯华 刘振华 《Journal of Medical Colleges of PLA(China)》 CAS 1992年第3期256-260,共5页
Left ventricular contractility was measured using Doppler echocardiography in 37 pa-tients with rheumatic mitral valve disease.Myocardial pathological lesions were studied quanti-tatively by means of the image analysi... Left ventricular contractility was measured using Doppler echocardiography in 37 pa-tients with rheumatic mitral valve disease.Myocardial pathological lesions were studied quanti-tatively by means of the image analysis system and light microscopic examination.The resultsshowed that attenuated cardiac function is due to pathological change of the mitral valve andpathological lesions of the left ventrieular myocardium including increased interstitial fibrosis,thickened intramyocardial arterial wall leading to concentric narrowing of the lumen,hyper-trophic myocardial fiber and endocardial proliferation.Since mitral valve replacement can notcorrect the irreversible myocardial pathological lesions,perioperative protection of the my-ocardium should be emphasized,and intraoperative injury to the myocardium should be mini-mized as far as possible. 展开更多
关键词 HEART valve PROSTHESIS PHYSIOPATHOLOGY PATHOLOGY HEART function tests MYOCARDIAL contractION human
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Common Fixed Points for Two Mappings with Implicit-linear Contractions on Partially Ordered 2-metric Spaces
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作者 PIAO YONG-JIE 《Communications in Mathematical Research》 CSCD 2019年第3期225-234,共10页
In this paper, we introduce a new class U of 3-dimensional real functions, use U and a 2-dimensional real function ? to construct a new implicit-linear contractive condition and obtain some existence theorems of commo... In this paper, we introduce a new class U of 3-dimensional real functions, use U and a 2-dimensional real function ? to construct a new implicit-linear contractive condition and obtain some existence theorems of common fixed points for two mappings on partially ordered 2-metric spaces and give a sufficient condition under which there exists a unique common fixed point. The obtained results goodly generalize and improve the corresponding conclusions in references. 展开更多
关键词 2-metric space class U of functions implicit-linear contractION common fixed point
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Unique Common Fixed Point for a Family of Mappings with a Nonlinear Quasi-Contractive Type Condition in Metrically Convex Spaces
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作者 Yongjie Piao 《Analysis in Theory and Applications》 CSCD 2015年第2期167-175,共9页
A class Ф of 5-dimensional functions was introduced and an existence and uniqueness of common fixed points for a family of non-self mappings satisfying a Фi- quasi-contractive condition and a certain boundary condit... A class Ф of 5-dimensional functions was introduced and an existence and uniqueness of common fixed points for a family of non-self mappings satisfying a Фi- quasi-contractive condition and a certain boundary condition was given on complete metrically convex metric spaces, and from which, more general unique common fixed point theorems were obtained. Our main results generalize and improve many same type common fixed point theorems in references. 展开更多
关键词 Metrically convex space a class Ф of 5-dimensional functions Фi-quasi-contraction common fixed point complete.
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前交叉韧带重建后肌肉等长发力率及与功能表现的关系 被引量:1
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作者 李奇 高明威 +4 位作者 李世浩 褚晓蕾 李亚杰 丁宁 刘敏琦 《中国组织工程研究》 CAS 北大核心 2024年第34期5536-5543,共8页
背景:前交叉韧带重建后肌肉功能的恢复通常评估肌肉的最大力量,最近的研究认为还应考虑神经肌肉功能,比如肌肉等长发力率,即在肌肉等长收缩条件下测量不同时间间隔的力-时间曲线斜率。目的:阐述前交叉韧带重建后患者肌肉等长发力率的研... 背景:前交叉韧带重建后肌肉功能的恢复通常评估肌肉的最大力量,最近的研究认为还应考虑神经肌肉功能,比如肌肉等长发力率,即在肌肉等长收缩条件下测量不同时间间隔的力-时间曲线斜率。目的:阐述前交叉韧带重建后患者肌肉等长发力率的研究现状与不足,分析术后不同时间内股四头肌和腘绳肌等长发力率的缺陷程度;等长发力率对术后患者功能表现的影响,为优化前交叉韧带重建后康复、减少患者二次损伤以及降低膝骨关节炎发生率提供重要信息。方法:检索中国知网、维普、万方和PubMed数据库,以“前交叉韧带,发力率”为中文检索词,以“anterior cruciate ligament,rate of force development,rate of torque development”为英文检索词,按照纳入和排除标准最终纳入69篇文献。结果与结论:(1)大多数研究发现前交叉韧带重建后半年内患者双侧肌肉等长发力率存在缺陷,双侧腘绳肌早期等长发力率(即肌肉收缩100 ms时间段内任意时间间隔的力-时间曲线斜率)在半年后有显著改善,但双侧股四头肌早期等长发力率长期缺陷,表明术后股四头肌神经肌肉功能长期受损。(2)有关晚期等长发力率(肌肉收缩100 ms后时间段内任意时间间隔的力-时间曲线斜率)的相关研究较少,无法得出确切结论。(3)关于着陆运动(跳跃落地和侧切等)和日常生活活动(走、跑),股四头肌早期等长发力率比等长峰值力矩相关性更强,运动过程中生物力学的异常改变被认为是患者二次损伤以及创伤性膝骨关节炎发生的重要风险因素,积极改善股四头肌早期等长发力率可能会降低二次损伤以及创伤性膝骨关节炎的发生率。(4)目前仅有很少的证据表明,全身振动训练能改善前交叉韧带重建后患者股四头肌早期等长发力率,建议今后在术后早期阶段应用神经肌肉电刺激干预股四头肌和腘绳肌,而在术后晚期阶段实施爆发力、高阻力训练,这可能会改善患者等长发力率。(5)短时间产生足够的肌肉力量才能有效保护前交叉韧带,而腘绳肌等长发力率与功能表现的关系尚不清楚,这可能会提供有关预防患者二次损伤的信息。(6)作者建议将等长发力率作为指导康复以及恢复运动的评估指标之一,除了关注对称性的改善以及与正常人的差异,还要考虑腘绳肌与股四头肌力量的比值,合适的比值范围才能保证肌肉快速发力时的平衡,这可能会降低再次损伤的发生,但比值的正常范围尚不清楚。(7)未来研究要考虑移植物类型和膝关节屈曲角度对等长发力率的影响,以尽可能找出患者存在的神经肌肉功能障碍,帮助患者更好地康复。 展开更多
关键词 发力率 等长收缩 前交叉韧带重建 神经肌肉功能 功能表现 二次损伤 股四头肌 综述
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