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Assessment of Regional Left Ventricular Myocardial Function in Rats after Acute Occlusion of Left Anterior Descending Artery by Two-dimensional Speckle Tracking Imaging 被引量:15
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作者 付倩 谢明星 +5 位作者 王静 王新房 吕清 卢晓芳 方凌云 程龙 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2009年第6期786-790,共5页
This study evaluated the change in regional left ventricular myocardial function in rats following acute occlusion of the left anterior descending coronary artery (LAD) by using two-dimensional speckle tracking imag... This study evaluated the change in regional left ventricular myocardial function in rats following acute occlusion of the left anterior descending coronary artery (LAD) by using two-dimensional speckle tracking imaging (2D-STI). Sixty Wistar rats were randomly divided into two groups, a myocardial infarction (MI) group, in which 50 rats were subjected to LAD occlusion for 30–45 min, and a sham-operated (SHAM) group that contained 10 rats serving as control. Echo-cardiography was performed at baseline and 1, 4 and 8 week(s) after the operation. High frequency two-dimensional images of left ventricular short axis at papillary muscle level were recorded. Peak systolic radial strain (PRS) and circumferential strain (PCS) were measured in the mid-ventricle in short-axis view by using EchoPAC workstation. Left ventricular internal diameter at diastole (LVIDd) and systole (LVIDs), fractional shortening (FS), ejection fraction (EF) and left ventricular mass (LVM) were measured by anatomical M-model echocardiography. Infarct size was measured using triphenyl tetrazolium chloride (TTC) staining 1 week and 8 weeks after the operation. Fibrosis of left ventricu-lar myocardium was displayed using Van Gieson staining 1 week after the infarction. In terms of the TTC staining results, the left ventricle fell into three categories: infarcted, peri-infarcted and remote myocardial regions. Compared with those at baseline and in the SHAM group, (1) PRS and PCS in the infarcted, peri-infarcted and remote myocardial regions were significantly decreased in the MI group within 1 week after the operation (P〈0.05) and the low levels lasted 8 weeks; (2) Compared with those at baseline, LVIDd, LVIDs, FS, EF and LVM in the MI group showed no significant dif-ference 1 week after the operation (P〉0.05). However, LVIDd, LVIDs and LVM were increased sig-nificantly 4 and 8 weeks after the operation (P〈0.05), and FS and EF were decreased substantially (P〈0.05). Van Gieson staining showed that fibrosis developed in all the three myocardial regions to varying degrees. It is concluded that 2D-STI is non-invasive and can be used to assess regional func-tion of myocardium with different blood supply in rats following acute occlusion of the LAD, and can be used as a sensitive and reliable means to follow up the process of left ventricular remodeling. 展开更多
关键词 ECHOCARDIOGRAPHY ventricular function left left ventricular remodeling two-dimensional strain
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Assessment of Myocardial Perfusion and Systolic Function in Patients with Coronary Artery Disease after Coronary Artery Bypass Surgery by Myocardial Contrast Echocardiography and Two-dimensional Strain Echocardiography 被引量:5
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作者 刘蓉 邓又斌 +3 位作者 毕小军 刘娅妮 熊莉 陈刘平 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2009年第5期664-668,共5页
The clinically applied value of myocardial perfusion and systolic function in patients with coronary artery disease after coronary artery bypass surgery using real-time myocardial contrast echocardiography (RT-MCE) ... The clinically applied value of myocardial perfusion and systolic function in patients with coronary artery disease after coronary artery bypass surgery using real-time myocardial contrast echocardiography (RT-MCE) combined with two-dimensional strain echocardiography was assessed. Twenty patients underwent intravenous RT-MCE by intravenous injections of SonoVue before and after coronary artery bypass surgery. Two-dimensional images were recorded from the left ventricular four-chamber view, two-chamber view and the apical view before, and two weeks and three months after coronary artery bypass surgery, and the peak systolic longitudinal strain was measured. The results showed that myocardial perfusion was significantly increased after coronary artery bypass surgery in about 71.6% segments. In the group that myocardial perfusion was improved, the peak systolic longitu- dinal strain three months after bypass surgery was significantly higher than that before operation [(-15.78±5.91)% vs (-10.45±8.31)%, P〈0.05]. However, the parameters did not change in the group without myocardial perfusion improvement [(-10.33±6.53)% vs (-9.41±6.09)%, P〉0.05]. It was concluded that whether or not the improvement of myocardial perfusion can mirror the recovery trend of regional systolic function, two-dimensional strain echocardiography can observe dynamic change of regional systolic function. The combination of myocardial perfusion with two-dimensional strain echocardiography can more accurately assess the curative effectiveness of coronary artery bypass surgery. 展开更多
关键词 two-dimensional strain myocardial contrast echocardiography myocardial perfusion ventricular function coronary artery disease
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GREEN FUNCTION ON TWO-PHASE SATURATED MEDIUM BY CONCENTRATED FORCE IN TWO-DIMENSIONAL DISPLACEMENT FIELD 被引量:3
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作者 丁伯阳 丁翠红 +1 位作者 陈禹 陶海冰 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2004年第8期951-956,共6页
The Green function on two-phase saturated medium by concentrated force has a broad and important use In seismology, seismic engineering, soil mechanics, geophysics, dynamic foundation theory and so on. According to th... The Green function on two-phase saturated medium by concentrated force has a broad and important use In seismology, seismic engineering, soil mechanics, geophysics, dynamic foundation theory and so on. According to the Green function on two-phase saturated medium by concentrated force in three-dimentional displacement field obtained by Ding Bo-yang et al., it gives out the Green function in two-dimensional displacement field by infinite integral method along x(3)-direction derived by De Hoop and Manolis. The method adopted in the thesis is simpler. The result will be simplified to the boundary element method of dynamic problem. 展开更多
关键词 concentrated force two-phase saturated medium two-dimensional Green function
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Green's functions of two-dimensional piezoelectric quasicrystal in half-space and bimaterials 被引量:1
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作者 Xiaoyu FU Xiang MU +2 位作者 Jinming ZHANG Liangliang ZHANG Yang GAO 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第2期237-254,共18页
In this paper,we obtain Green’s functions of two-dimensional(2D)piezoelectric quasicrystal(PQC)in half-space and bimaterials.Based on the elastic theory of QCs,the Stroh formalism is used to derive the general soluti... In this paper,we obtain Green’s functions of two-dimensional(2D)piezoelectric quasicrystal(PQC)in half-space and bimaterials.Based on the elastic theory of QCs,the Stroh formalism is used to derive the general solutions of displacements and stresses.Then,we obtain the analytical solutions of half-space and bimaterial Green’s functions.Besides,the interfacial Green’s function for bimaterials is also obtained in the analytical form.Before numerical studies,a comparative study is carried out to validate the present solutions.Typical numerical examples are performed to investigate the effects of multi-physics loadings such as the line force,the line dislocation,the line charge,and the phason line force.As a result,the coupling effect among the phonon field,the phason field,and the electric field is prominent,and the butterfly-shaped contours are characteristic in 2D PQCs.In addition,the changes of material parameters cause variations in physical quantities to a certain degree. 展开更多
关键词 Green’s function two-dimensional(2D)piezoelectric quasicrystal(PQC) Stroh formalism HALF-SPACE bimaterial
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Band gaps structure and semi-Dirac point of two-dimensional function photonic crystals 被引量:1
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作者 Si-Qi Zhang Jing-Bin Lu +6 位作者 Yu Liang Ji Ma Hong Li Xue Li Xiao-Jing Liu Xiang-Yao Wu Xiang-Dong Meng 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第2期242-249,共8页
Two-dimensional function photonic crystals, in which the dielectric constants of medium columns are the functions of space coordinates , are proposed and studied numerically. The band gaps structures of the photonic c... Two-dimensional function photonic crystals, in which the dielectric constants of medium columns are the functions of space coordinates , are proposed and studied numerically. The band gaps structures of the photonic crystals for TE and TM waves are different from the two-dimensional conventional photonic crystals. Some absolute band gaps and semiDirac points are found. When the medium column radius and the function form of the dielectric constant are modulated, the numbers, width, and position of band gaps are changed, and the semi-Dirac point can either occur or disappear. Therefore,the special band gaps structures and semi-Dirac points can be achieved through the modulation on the two-dimensional function photonic crystals. The results will provide a new design method of optical devices based on the two-dimensional function photonic crystals. 展开更多
关键词 two-dimensional photonic crystals function dielectric constants band gaps structures
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Modulated synthesis of stoichiometric and sub-stoichiometric two-dimensional covalent organic frameworks for enhanced ethylene purification
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作者 Jiahao Li Guinan Chen +5 位作者 Chunhong Chen Yuanyuan Lou Zhihao Xing Tao Zhang Chengtao Gong Yongwu Peng 《Chinese Chemical Letters》 2025年第1期272-276,共5页
Controlled synthesis of two-dimensional covalent organic frameworks(2D COFs),including stoichiometric and sub-stoichiometric variations,is a topic of growing interest due to its potential in gas separation application... Controlled synthesis of two-dimensional covalent organic frameworks(2D COFs),including stoichiometric and sub-stoichiometric variations,is a topic of growing interest due to its potential in gas separation applications.In this study,we successfully synthesized three distinct 2D COFs by carefully adjusting solvent compositions and monomer ratios during the synthesis of[4+4]type COFs.These included a stoichiometric[4+4]type COF and two sub-stoichiometric[4+2]type COFs,featuring unreacted amino or formyl groups.The resulting COFs exhibit different gas adsorption and separation properties.Specifically,sub-stoichiometric COF-DA with residual amino groups shows comparable adsorption capacity for C_(2)H_(2),C_(2)H_(4),and CO_(2)to stoichiometric COF-DAPy.In contrast,sub-stoichiometric COF-Py with residual formyl groups displays enhanced adsorption selectivity for C_(2)H_(2)/C_(2)H_(4)and C_(2)H_(2)/CO_(2)separation,with the C_(2)H_(2)/C_(2)H_(4)selectivity being the highest among reported COFs,attributed to increased pore polarity resulting from the presence of formyl groups.This study not only offers an additional example of substoichiometric COF synthesis but also advocates for further exploration of sub-stoichiometric COF materials,particularly in the field of gas adsorption and separation. 展开更多
关键词 two-dimensional covalent organic frameworks Stoichiometric and sub-stoichiometric Residual functional groups Ethylene purification
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GENERALIZED COUNTING FUNCTIONS AND COMPOSITION OPERATORS ON WEIGHTED BERGMAN SPACES OF DIRICHLET SERIES
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作者 Min HE Maofa WANG Jiale CHEN 《Acta Mathematica Scientia》 2025年第2期291-309,共19页
In this paper,we study composition operators on weighted Bergman spaces of Dirichlet series.We first establish some Littlewood-type inequalities for generalized mean counting functions.Then we give sufficient conditio... In this paper,we study composition operators on weighted Bergman spaces of Dirichlet series.We first establish some Littlewood-type inequalities for generalized mean counting functions.Then we give sufficient conditions for a composition operator with zero characteristic to be bounded or compact on weighted Bergman spaces of Dirichlet series.The corresponding sufficient condition for compactness in the case of positive characteristics is also obtained. 展开更多
关键词 generalized counting function Dirichlet series composition operator weighted Bergman space
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Two-dimensional Pt_(2)P_(3)monolayer:A promising bifunctional electrocatalyst with different active sites for hydrogen evolution and CO_(2)reduction
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作者 Yuting Sun Shuang Wang +6 位作者 Dongxu Jiao Fengyu Li Siyao Qiu Zhongxu Wang Qinghai Cai Jingxiang Zhao Chenghua Sun 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第8期3987-3992,共6页
Green hydrogen production and CO_(2) fixation have been identified as the fundamental techniques for sustainable economy.The open challenge is to develop high performance catalysts for hydrogen evolution reaction(HER)... Green hydrogen production and CO_(2) fixation have been identified as the fundamental techniques for sustainable economy.The open challenge is to develop high performance catalysts for hydrogen evolution reaction(HER)and CO_(2) electroreduction(CO_(2)ER)to valuable chemicals.Under such context,this work reported computational efforts to design promising electrocatalyst for HER and CO_(2)ER based on the swarm-intelligence algorithm.Among the family of transition-metal phosphides(TMPs),Pt_(2)P_(3) monolayer has been identified as excellent bifunctional catalysts due to high stability,excellent conductivity and superior catalytic performance.Different from typical d-block catalysts,p-band center presented by P atoms within Pt_(2)P_(3) monolayer plays the essential role for its reactivity towards HER and CO_(2)ER,underlining the key value of p-electrons in advanced catalyst design and thus providing a promising strategy to further develop novel catalysts made of p-block elements for various energy applications. 展开更多
关键词 Bifunctional electrocatalysts HER/CO_(2)ER Swarm-intelligence structure search Density functional theory two-dimensional Monolayer
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Comment on “Band gaps structure and semi-Dirac point of two-dimensional function photonic crystals” by Si-Qi Zhang et al.
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作者 章海锋 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第1期618-622,共5页
Recently, Zhang et al. (Chin. Phys. B 26 024208 (2017)) investigated the band gap structures and semi-Dirac point of two-dimensional function photonic crystals, and the equations for the plane wave expansion metho... Recently, Zhang et al. (Chin. Phys. B 26 024208 (2017)) investigated the band gap structures and semi-Dirac point of two-dimensional function photonic crystals, and the equations for the plane wave expansion method were induced to obtain the band structures. That report shows the band diagrams with the effects of function coefficient k and medium column ra under TE and TM waves. The proposed results look correct at first glance, but the authors made some mistakes in their report. Thus, the calculated results in their paper are incorrect. According to our calculations, the errors in their report are corrected, and the correct band structures also are presented in this paper. 展开更多
关键词 two-dimensional function photonic crystals photonic band gaps plane wave expansion method Monte Carlo method
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Static response of functionally graded multilayered two-dimensional quasicrystal plates with mixed boundary conditions
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作者 Xin FENG Liangliang ZHANG +3 位作者 Yuxuan WANG Jinming ZHANG Han ZHANG Yang GAO 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第11期1599-1618,共20页
The unusual properties of quasicrystals(QCs)have attracted tremendous attention from researchers.In this paper,a semi-analytical solution is presented for the static response of a functionally graded(FG)multilayered t... The unusual properties of quasicrystals(QCs)have attracted tremendous attention from researchers.In this paper,a semi-analytical solution is presented for the static response of a functionally graded(FG)multilayered two-dimensional(2 D)decagonal QC rectangular plate with mixed boundary conditions.Based on the elastic theory of FG 2 D QCs,the state-space method is used to derive the state equations composed of partial differential along the thickness direction.Besides,the Fourier series expansion and the differential quadrature technique are utilized to simulate the simply supported boundary conditions and the mixed boundary conditions,respectively.Then,the propagator matrix which connects the field variables at the upper interface to those at the lower interface of any homogeneous layer can be derived based on the state equations.Combined with the interface continuity condition,the static response can be obtained by imposing the sinusoidal load on the top surfaces of laminates.Finally,the numerical examples are presented to verify the effectiveness of this method,and the results are very useful for the design and understanding of the characterization of FG QC materials in their applications to multilayered systems. 展开更多
关键词 two-dimensional(2D)quasicrystal(QC)laminate functionally graded material(FGM) mixed boundary condition static response differential quadrature technique
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Value of myocardial function in children with Kawasaki disease by two-dimensional and three-dimensional ultrasound speckle tracking
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作者 Ya-Mei Shen Tao-Min Bai +4 位作者 Xue-Mei Zhang Chun-Miao Kang Xiao-Ni Chang Yan-Hua Gao Xiao-Hua Yan 《Journal of Hainan Medical University》 2019年第21期58-61,共4页
Objective:To investigate the value of two-dimensional ultrasound speckle tracking(2D-STI)and three-dimensional ultrasound speckle tracking(3D-STI)in evaluating myocardial function in children with Kawasaki disease.Met... Objective:To investigate the value of two-dimensional ultrasound speckle tracking(2D-STI)and three-dimensional ultrasound speckle tracking(3D-STI)in evaluating myocardial function in children with Kawasaki disease.Methods 92 children with Kawasaki disease admitted to our hospital from February 2017 to February 2019 were retrospectively analyzed.50 children who underwent 3D-STI examination were taken as observation group and 42 children who underwent 2D-STI examination were taken as control group.The left ventricular systolic function index,storage time and analysis time of the image,the diameter of coronary artery,the strain difference of left ventricular basal segment,middle segment,apical segment and whole segment were observed.Results The levels of left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricular myocardial mass(LVMI)in the observation group were higher than those in the control group(P<0.05),but there was no statistical difference in left ventricular ejection fraction(LVEF)between the two groups(P>0.05).The storage time and analysis time of the image in the observation group were significantly lower than those in the control group(P<0.05).The left coronary artery(LCA)and right coronary artery(RCA)in the observation group were higher than those in the control group(P<0.05).There was no statistical difference between left anterior descending(LAD)in the two groups(P>0.05).The longitudinal peak systolic strain(LS),circumferential peak systolic strain(CS)and radial peak systolic strain(RS)in the observation group were higher than those in the control group(P<0.05).The global longitudinal peak strain(GLS),global circumferential peak strain(GCS)and global radial peak strain(GRS)in the observation group were higher than those in the control group(P<0.05).LS and CS in the middle segment of the observation group were higher than those in the control group(P<0.05).Conclusions Compared with 2D-STI,3D-STI can objectively and accurately reflect the myocardial function of children with Kawasaki disease. 展开更多
关键词 KAWASAKI disease two-dimensional ULTRASOUND SPECKLE TRACKING three-dimensional ULTRASOUND SPECKLE TRACKING myocardial function left ventricular systolic function
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Evaluation of the Effect of Sigmoid-Shaped Interventricular Septum on Left Ventricular Systolic Function in Patients with Essential Hypertension by Two-Dimensional Speckle Tracking Echocardiography
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作者 Zhifan Zhang Wei Xu +2 位作者 Yudong Peng Hong Zhang Qi Zhang 《Yangtze Medicine》 2020年第1期62-69,共8页
Objective: To evaluate left ventricular regional and global systolic function by measuring left ventricular longitudinal strain (LS) in hypertensive patients with sigmoid-shaped interventricular septum (SIS) by two-di... Objective: To evaluate left ventricular regional and global systolic function by measuring left ventricular longitudinal strain (LS) in hypertensive patients with sigmoid-shaped interventricular septum (SIS) by two-dimensional speckle tracking (2D-STE);in order to explore whether the sigmoid-shaped interventricular septum affects the left ventricular systolic function in patients with hypertension. Methods: Routine echocardiographic parameters were measured in 30 hypertensive patients with SIS (SIS group) and 30 hypertensive patients without SIS (non-SIS group). The left ventricular segments and global LS were measured by 2D-STE, and the two sets of parameters were compared. Results: The value of the thickness of the basal segment of the interventricular septum (IVSBT), the thickness of the middle segment of the interventricular septum (IVSMT) and the ratio of the basal segment of the ventricular septum to the middle segment of the interventricular septum (IVSBT/IVSMT) in SIS group was higher than that in non-SIS group. However, the value of left ventricular outflow tract diameter (LVOTD) in SIS group was lower than that in non-SIS group. There was a significant difference between the two groups (all P Conclusion: SIS affects left ventricular regional systolic function of patients with hypertension. 2D-STE can early evaluate left ventricular longitudinal systolic function in hypertensive patients with SIS. 展开更多
关键词 Sigmoid-Shaped INTERVENTRICULAR SEPTUM Hypertension Left Ventricular SYSTOLIC function two-dimensional Speckle Tracking ECHOCARDIOGRAPHY ECHOCARDIOGRAPHY
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Value of two-dimensional speckle tracking imaging in quantitative assessment of left ventricular function in patients with OSAS
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作者 Guo-Ping Xie Qing-Shan Lin Chao Yu 《Journal of Hainan Medical University》 2019年第10期75-78,共4页
Objective: To research the clinical application of two-dimensional speckle tracking imaging (2D-STI) in quantitative assessment of left ventricular function in patients with obstructive sleep apnea-hypopnea syndrome (... Objective: To research the clinical application of two-dimensional speckle tracking imaging (2D-STI) in quantitative assessment of left ventricular function in patients with obstructive sleep apnea-hypopnea syndrome (OSAS). Method: From July 2016 to December 2018, 86 patients with OSAS were selected as OSAS group. According to sleep apnea hypopnea index (AHI), they were divided into mild OSAS group (24 cases), moderate OSAS group (29 cases) and severe OSAS group (33 cases). Another 50 healthy volunteers who underwent physical examination in our hospital during the same period were selected as the control group. The left ventricular function of all patients was quantitatively assessed by 2D-STI. The left ventricular function of all patients was quantitatively assessed by 2D-STI. The results of routine echocardiography and left ventricular global strain parameters of the OSAS group, the control group and the OSAS patients with different severity were compared and analyzed. Result: There were no significant differences in the levels of left ventricular ejection fraction (LVEF), left ventricular end diastolic diameter (LVEDd), left ventricular end systolic diameter (LVESd) between the two groups and OSAS patients with different severity (P>0.05). The levels of IVST, LVPW and LVMI in the OSAS group were significantly higher than those in the control group, the levels of end-diastolic interventricular septal thickness (IVS), left ventricular posterior wall thickness (LVPW), left ventricular mass index (LVMI) in the severe OSAS group were significantly higher than those in the mild and moderate OSAS group, and the levels of IVST, LVPW and LVMI in the moderate OSAS group were significantly higher than those in the mild OSAS group, there were significant differences between groups (P<0.05). The levels of GLS, GRS and GCS in the OSAS group were significantly lower than those in the control group (P<0.05). GLS, GRS and GCS levels in the severe OSAS group were significantly lower than those in the mild OSAS group and the moderate OSAS group, while the levels of global longitudinal strain (GLS), global radial strain (GRS) and global circumferential strain (GCS) in the moderate OSAS group were significantly lower than those in the mild OSAS group (P<0.05). Conclusion: The left ventricular systolic function of OSAS patients is obviously impaired. Left ventricular function in OSAS patients can be assessed timely and accurately by two-dimensional speckle tracking imaging. 展开更多
关键词 OBSTRUCTIVE sleep APNEA HYPOPNEA syndrome Echocardiography LEFT VENTRICULAR global strain parameters two-dimensional speckle tracking imaging LEFT VENTRICULAR function
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Beneficial effects of antidepressant mirtazapine in functional dyspepsia patients with weight loss 被引量:21
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作者 Shu-Man Jiang Lin Jia +2 位作者 Jing Liu Man-Man Shi Ming-Zhi Xu 《World Journal of Gastroenterology》 SCIE CAS 2016年第22期5260-5266,共7页
AIM: To explore the effects and mechanism of action of antidepressant mirtazapine in functional dyspepsia(FD) patients with weight loss.METHODS: Sixty depressive FD patients with weight loss were randomly divided into... AIM: To explore the effects and mechanism of action of antidepressant mirtazapine in functional dyspepsia(FD) patients with weight loss.METHODS: Sixty depressive FD patients with weight loss were randomly divided into a mirtazapine group(MG), a paroxetine group(PG) or a conventional therapy group(CG) for an 8-wk clinical trial. Adverse effects and treatment response were recorded. The Nepean Dyspepsia Index-symptom(NDSI) checklist and the 17-item Hamilton Rating Scale of Depression(HAMD-17) were used to evaluate dyspepsia and depressive symptoms, respectively. The body composition analyzer was used to measure body weight and fat. Serum hormone levels were measured by ELISA.RESULTS:(1) After 2 wk of treatment, NDSI scores were significantly lower for the MG than for the PG and CG;(2) After 4 or 8 wk of treatment, HAMD-17 scores were significantly lower for the MG and PG than for the CG;(3) After 8 wk of treatment, patients in the MG experienced a weight gain of 3.58 ± 1.57 kg, which was significantly higher than that observed for patients in the PG and CG. Body fat increased by 2.77 ± 0.14kg, the body fat ratio rose by 4%, and the visceral fat area increased by 7.56 ± 2.25 cm2; and(4) For the MG, serum hormone levels of ghrelin, neuropeptide Y(NPY), motilin(MTL) and gastrin(GAS) were significantly upregulated; in contrast, those of leptin, 5-hydroxytryptamine(5-HT) and cholecystokinin(CCK) were significantly downregulated. CONCLUSION: Mirtazapine not only alleviates symptoms associated with dyspepsia and depression linked to FD in patients with weight loss but also significantly increases body weight(mainly the visceral fat in body fat). The likely mechanism of mirtazapine action is regulation of brain-gut or gastrointestinal hormone levels. 展开更多
关键词 Mirtazapine functionAL DYSPEPSIA weight LOSS DEPRESSION
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Consequences of gestational and pregestational diabetes on placental function and birth weight 被引量:14
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作者 Anne Vambergue Isabelle Fajardy 《World Journal of Diabetes》 SCIE CAS 2011年第11期196-203,共8页
Maternal diabetes constitutes an unfavorable environment for embryonic and fetoplacental development. Despite current treatments, pregnant women with pregestational diabetes are at increased risk for congenital malfor... Maternal diabetes constitutes an unfavorable environment for embryonic and fetoplacental development. Despite current treatments, pregnant women with pregestational diabetes are at increased risk for congenital malformations, materno-fetal complications, placental abnormalities and intrauterine malprogramming. The complications during pregnancy concern the mother (gravidic hypertension and/or preeclampsia, cesarean section) and the fetus (macrosomia or intrauterine growth restriction, shoulder dystocia, hypoglycemia and respiratory distress). The fetoplacental impairment and intrauterine programming of diseases in the offspring's later life induced by gestational diabetes are similar to those induced by type 1 and type 2 diabetes mellitus. Despite the existence of several developmental and morphological differences in the placenta from rodents and women, there are similarities in the alterations induced by maternal diabetes in the placenta from diabetic patients and diabetic experimental models. From both human and rodent diabetic experimentalmodels, it has been suggested that the placenta is a compromised target that largely suffers the impact of maternal diabetes. Depending on the maternal metabolic and proin ammatory derangements, macrosomia is explained by an excessive availability of nutrients and an increase in fetal insulin release, a phenotype related to the programming of glucose intolerance. The degree of fetal damage and placental dysfunction and the availability and utilisation of fetal substrates can lead to the induction of macrosomia or intrauterine growth restriction. In maternal diabetes, both the maternal environment and the genetic background are important in the complex and multifactorial processes that induce damage to the embryo, the placenta, the fetus and the offspring. Nevertheless, further research is needed to better understand the mechanisms that govern the early embryo development, the induction of congenital anomalies and fetal overgrowth in maternal diabetes. 展开更多
关键词 Maternal diabetes PLACENTAL function BIRTH weight MACROSOMIA INTRAUTERINE growth RETARDATION
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Updates on the relation of weight excess and reproductive function in men: sleep apnea as a new area of interest 被引量:11
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作者 Ahmad O Hammoud Douglas T Carrell +2 位作者 Mark Gibson C Matthew Peterson A Wayne Meikle 《Asian Journal of Andrology》 SCIE CAS CSCD 2012年第1期77-81,176,177,共7页
Obesity has a negative effect on male reproductive function. It is associated with low testosterone levels and alteration in gonadotropin secretion. Male obesity has been linked to reduced male fertility. Data regardi... Obesity has a negative effect on male reproductive function. It is associated with low testosterone levels and alteration in gonadotropin secretion. Male obesity has been linked to reduced male fertility. Data regarding the relation of obesity to sperm parameters are conflicting in terms of the nature and magnitude of the effect. New areas of interest are emerging that can help explain the variation in study results, such as genetic polymorphism and sleep apnea. Sleep disorders have been linked to altered testosterone production and hypogonadism in men. It was also correlated to erectile dysfunction. The relation of sleep disorders to male fertility and sperm parameters remains to be investigated. Men with hypogonadism and infertility should be screened for sleep apnea. Treatment of obesity and sleep apnea improves testosterone levels and erectile function. 展开更多
关键词 INFERTILITY male infertility reproductive function sleep apnea weight excess
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Temperature and Water Vapor Weighting Functions from Radiative Transfer Equation with Surface Emissivity and Solar Reflectivity 被引量:11
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作者 李俊 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1994年第4期421-426,共6页
Linearization of Radiative Transfer Equation (RTE) is the key step in physical retrieval of atmospheric temperature and moisture profiles from InfRared (IR) sounder observations. In this paper, the successive forms of... Linearization of Radiative Transfer Equation (RTE) is the key step in physical retrieval of atmospheric temperature and moisture profiles from InfRared (IR) sounder observations. In this paper, the successive forms of temperature and water vapor mixing ratio component weighting functions are derived by applying one term variation method to RTE with surface emissivity and solar reflectivity contained. Retrivals of temperature and water vapor mixing ratio profiles from simulated Atmospheric Infrared Sounder (AIRS) observations with surface emissivity and solar reflectivity are presented. 展开更多
关键词 Radiative Transfer Equation weighting function RETRIEVAL
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Construction mechanism of whitenization weight function and its application in grey clustering evaluation 被引量:7
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作者 XIE Naiming SU Bentao CHEN Nanlei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第1期121-131,共11页
The clustering evaluation can be used to scientifically classify the objects to be evaluated according to the information aggregation of various evaluation rules. In grey weighted clustering evaluation, the index clus... The clustering evaluation can be used to scientifically classify the objects to be evaluated according to the information aggregation of various evaluation rules. In grey weighted clustering evaluation, the index clustering rule relies on the construction of the whitenization weight function, while the existing construction method of the linear function lacks the construction mechanism analysis and validity explanation. A normative construction principle is put forward by analyzing the construction mechanism of the function. Through proving the normative principle of the function,the basic modal function(BMF) is proposed and characterized by different function forms. Then, a new type of the whitenization weight function and its grey clustering evaluation model algorithm are given by studying the mechanism and nature of the construction of different forms of the function. Finally, the comparative study for self-innovation capability of defense science and technology industry(DSTI) is taken as an example. The results show that the different construction ways of the function have an effect on the clustering result. The proposed construction mechanism can better explain the index clustering rules and evaluation effectiveness,which will perfect the theoretical system of grey clustering evaluation and be applied to practice effectively. 展开更多
关键词 whitenization weight function GREY system THEORY GREY CLUSTERING evaluation.
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Optimum Weight Design of Functionally Graded Material Gears 被引量:8
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作者 JING Shikai ZHANG He +1 位作者 ZHOU Jingtao SONG Guohua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第6期1186-1193,共8页
Traditional gear weight optimization methods consider gear tooth number, module, face width or other dimension parameters of gear as design variables. However, due to the complicated form and geometric features peculi... Traditional gear weight optimization methods consider gear tooth number, module, face width or other dimension parameters of gear as design variables. However, due to the complicated form and geometric features peculiar to the gear, there will be large amounts of design parameters in gear design, and the influences of gear parameters changing on gear trains, transmission system and the whole equipment have to be taken into account, which increases the complexity of optimization problem. This paper puts forward to apply functionally graded materials(FGMs) to gears and then conduct the optimization. According to the force situation of gears, the material distribution form of FGM gears is determined. Then based on the performance parameters analysis of FGMs and the practical working demands for gears, a multi-objective optimization model is formed. Finally by using the goal driven optimization(GDO) method, the optimal material distribution is achieved, which makes gear weight and the maximum deformation be minimum and the maximum bending stress do not exceed the allowable stress. As an example, the applying of FGM to automotive transmission gear is conducted to illustrate the optimization design process and the result shows that under the condition of keeping the normal working performance of gear, the method achieves in greatly reducing the gear weight. This research proposes a FGM gears design method that is able to largely reduce the weight of gears by optimizing the microscopic material parameters instead of changing the macroscopic dimension parameters of gears, which reduces the complexity of gear weight optimization problem. 展开更多
关键词 GEARS optimum weight design functionally graded materials material distribution additive manufacturing
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Weighted Multi-sensor Data Level Fusion Method of Vibration Signal Based on Correlation Function 被引量:7
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作者 BIN Guangfu JIANG Zhinong +1 位作者 LI Xuejun DHILLON B S 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第5期899-904,共6页
As the differences of sensor's precision and some random factors are difficult to control,the actual measurement signals are far from the target signals that affect the reliability and precision of rotating machinery... As the differences of sensor's precision and some random factors are difficult to control,the actual measurement signals are far from the target signals that affect the reliability and precision of rotating machinery fault diagnosis.The traditional signal processing methods,such as classical inference and weighted averaging algorithm usually lack dynamic adaptability that is easy for trends to cause the faults to be misjudged or left out.To enhance the measuring veracity and precision of vibration signal in rotary machine multi-sensor vibration signal fault diagnosis,a novel data level fusion approach is presented on the basis of correlation function analysis to fast determine the weighted value of multi-sensor vibration signals.The approach doesn't require knowing the prior information about sensors,and the weighted value of sensors can be confirmed depending on the correlation measure of real-time data tested in the data level fusion process.It gives greater weighted value to the greater correlation measure of sensor signals,and vice versa.The approach can effectively suppress large errors and even can still fuse data in the case of sensor failures because it takes full advantage of sensor's own-information to determine the weighted value.Moreover,it has good performance of anti-jamming due to the correlation measures between noise and effective signals are usually small.Through the simulation of typical signal collected from multi-sensors,the comparative analysis of dynamic adaptability and fault tolerance between the proposed approach and traditional weighted averaging approach is taken.Finally,the rotor dynamics and integrated fault simulator is taken as an example to verify the feasibility and advantages of the proposed approach,it is shown that the multi-sensor data level fusion based on correlation function weighted approach is better than the traditional weighted average approach with respect to fusion precision and dynamic adaptability.Meantime,the approach is adaptable and easy to use,can be applied to other areas of vibration measurement. 展开更多
关键词 vibration signal MULTI-SENSOR data level fusion correlation function weighted value
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