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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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Evaluation of Epirubicin-induced Cardiotoxicity by Two-dimensional Strain Echocardiography in Breast Cancer Patients 被引量:2
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作者 毕小军 邓又斌 +4 位作者 曾繁静 朱英 伍玉晗 赵策瑶 黎春雷 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2009年第3期391-394,共4页
The value of two-dimensional strain echocardiography for assessing left ventricular regional systolic function in breast cancer patients who were treated with epirubicin was evaluated. A total of 116 breast cancer pat... The value of two-dimensional strain echocardiography for assessing left ventricular regional systolic function in breast cancer patients who were treated with epirubicin was evaluated. A total of 116 breast cancer patients were divided into 3 groups: Thirty-eight patients in group A were given epirubicin (Epi) of 120-340 mg/m^2, 42 patients in group B received epimbicin of≥ 360 mg/m^2, and 36 patients after surging without chemotherapy served as the control group C. High frame rate two-dimensional images were recorded from apical long-axis view, four-chamber view, two-chamber view of left ventricle. Peak systolic strain of left ventricular subendocardial myocardium was measured using two-dimensional strain software. The conventional echocardiographic parameters were also obtained. Conventional echocardiography showed there was no significant changes in conventional echocardiographic parameters among the three groups (P〉0.05). Two-dimensional strain echocardiography revealed that the peak systolic strain of left ventricular subendocardial myocardium in group A was reduced in some segments as compared with the controls (P〈0.05). The peak systolic strain of left ventricular subendocardial myocardium in group B was reduced significantly as com- pared with group C (P〈0.05), but that was reduced in group B just in some of the segments as compared with group A (P〈0.05). It was concluded that two-dimensional strain echocardiography could early and sensitively display the effects of epirubicin-induced cardiotoxicity on the systolic function of left ventricular subendocardial myocardium, and early monitor the epirubicin-induced cardiotoxicity. 展开更多
关键词 echoeardiography EPIRUBICIN CARDIOTOXICITY breast cancer subendocardial myocardium two-dimensional strain
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Two-dimensional plane strain consolidation of unsaturated soils considering the depth-dependent stress 被引量:1
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作者 Lei Wang Sidong Shen +2 位作者 Tianyi Li Minjie Wen Annan Zhou 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第6期1603-1614,共12页
In practical engineering,the total vertical stress in the soil layer is not constant due to stress diffusion,and varies with time and depth.Therefore,the purpose of this paper is to investigate the effect of stress di... In practical engineering,the total vertical stress in the soil layer is not constant due to stress diffusion,and varies with time and depth.Therefore,the purpose of this paper is to investigate the effect of stress diffusion on the two-dimensional(2D)plane strain consolidation properties of unsaturated soils when the stress varies with time and depth.A series of semi-analytical solutions in terms of excess pore air and water pressures and settlement for 2D plane strain consolidation of unsaturated soils can be derived with the joint use of Laplace transform and Fourier sine series expansion.Then,the inverse Laplace transform of the semi-analytical solution is given in the time domain using a self-programmed code based on Crump’s method.The reliability of the obtained solutions is proved by the degeneration.Finally,the 2D plots of excess pore pressures and the curves of settlement varying with time,considering different physical parameters of unsaturated soil stratum and depth-dependent stress,are depicted and analyzed to study the 2D plane strain consolidation properties of unsaturated soils subjected to the depthdependent stress. 展开更多
关键词 Semi-analytical solutions two-dimensional(2D)plane strain CONSOLIDATION Unsaturated soils Depth-dependent stress Laplace transform
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Strain engineering and hydrogen effect for two-dimensional ferroelectricity in monolayer group-Ⅳmonochalcogenides MX(M=Sn,Ge;X=Se,Te,S)
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作者 Maurice Franck Kenmogne Ndjoko 郭必诞 +1 位作者 彭银辉 赵宇军 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期396-401,共6页
Two-dimensional(2D)ferroelectric compounds are a special class of materials that meet the need for devices miniaturization,which can lead to a wide range of applications.Here,we investigate ferroelectric properties of... Two-dimensional(2D)ferroelectric compounds are a special class of materials that meet the need for devices miniaturization,which can lead to a wide range of applications.Here,we investigate ferroelectric properties of monolayer group-IV monochalcogenides MX(M=Sn,Ge;X=Se,Te,S)via strain engineering,and their effects with contaminated hydrogen are also discussed.GeSe,GeTe,and GeS do not go through transition up to the compressive strain of-5%,and consequently have good ferroelectric parameters for device applications that can be further improved by applying strain.According to the calculated ferroelectric properties and the band gaps of these materials,we find that their band gap can be adjusted by strain for excellent photovoltaic applications.In addition,we have determined the most stable hydrogen occupancy location in the monolayer SnS and SnTe.It reveals that H prefers to absorb on SnS and SnTe monolayers as molecules rather than atomic H.As a result,hydrogen molecules have little effect on the polarization and electronic structure of monolayer SnTe and SnS. 展开更多
关键词 two-dimensional material strain engineering ferroelectric photovoltaic materials hydrogen effect
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Experimental and Numerical Study of the Effect of Surround Protection Technique on the Strain Measurement for Offshore Jacket Platform
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作者 Yongjun Xu 《Engineering(科研)》 2011年第5期485-490,共6页
For strain measurement on offshore jacket platform in deep water, waterproof of strain foil is always an important issue, especially, due to the high pressure in deep water. The waterproof is difficult in two places, ... For strain measurement on offshore jacket platform in deep water, waterproof of strain foil is always an important issue, especially, due to the high pressure in deep water. The waterproof is difficult in two places, one is between the matrix structure and the protection structure, and another is between the lead wires and the protection structure. The surround protection technique discussed in this paper is conventional and ideal, and can be operative for a long time, up to five years. In this method, a metal case and tube is added on the local position, which increases the local rigidity, but the effect on the measurement of strain is not well studied. In this paper, the effect of the surround protection technique on the strain measurement is studied by using numerical and experimental methods, and the results show that the measurement error is well in the range permitted by engineering practice. 展开更多
关键词 OFFSHORE JACKET Platform strain Measurement strain Foil SURROUND Protect/Waterproof technique
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Simple Culture Techniques for Germinationpromoting Fungi and Armillariella mellea in Artificial Planting of Gastrodia elata 被引量:2
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作者 谢学强 《Agricultural Science & Technology》 CAS 2016年第9期2005-2007,2016,共4页
This study aimed to explore simple culture techniques for symbiotic germination-promoting fungi and Armillariella mellea in artificial planting of Gastrodia elata, i.e., how to use a corner of ordinary house as inocul... This study aimed to explore simple culture techniques for symbiotic germination-promoting fungi and Armillariella mellea in artificial planting of Gastrodia elata, i.e., how to use a corner of ordinary house as inoculation room and cultivating site, how to use a pressure cooker for cooking food as sterilization tool, and how to use ordinary household heating as heating measures. 展开更多
关键词 Gastrodia elata BI. Germination-promoting strain Armillariella mellea Artificial planting of G. elata Simple culture technique
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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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Magnetic and electronic properties of two-dimensional metal-organic frameworks TM_(3)(C_(2)NH)_(12)
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作者 Zhen Feng Yi Li +2 位作者 Yaqiang Ma Yipeng An Xianqi Dai 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第9期1-12,共12页
The ferromagnetism of two-dimensional(2D)materials has aroused great interest in recent years,which may play an important role in the next-generation magnetic devices.Herein,a series of 2D transition metal-organic fra... The ferromagnetism of two-dimensional(2D)materials has aroused great interest in recent years,which may play an important role in the next-generation magnetic devices.Herein,a series of 2D transition metal-organic framework materials(TM-NH MOF,TM=Sc-Zn)are designed,and their electronic and magnetic characters are systematically studied by means of first-principles calculations.Their structural stabilities are examined through binding energies and ab-initio molecular dynamics simulations.Their optimized lattice constants are correlated to the central TM atoms.These 2D TM-NH MOF nanosheets exhibit various electronic and magnetic performances owing to the effective charge transfer and interaction between TM atoms and graphene linkers.Interestingly,Ni-and Zn-NH MOFs are nonmagnetic semiconductors(SM)with band gaps of 0.41 eV and 0.61 eV,respectively.Co-and Cu-NH MOFs are bipolar magnetic semiconductors(BMS),while Fe-NH MOF monolayer is a half-semiconductor(HSM).Furthermore,the elastic strain could tune their magnetic behaviors and transformation,which ascribes to the charge redistribution of TM-3d states.This work predicts several new 2D magnetic MOF materials,which are promising for applications in spintronics and nanoelectronics. 展开更多
关键词 two-dimensional metal-organic frameworks electronic structure magnetic property strain engineering
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First-principles study of a new BP_(2)two-dimensional material
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作者 Zhizheng Gu Shuang Yu +6 位作者 Zhirong Xu Qi Wang Tianxiang Duan Xinxin Wang Shijie Liu Hui Wang Hui Du 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第8期542-546,共5页
Two-dimensional materials have a wide range of applications in many aspects due to their unique properties. Here we carry out a detailed structural search and design of the BP2using the first principles method, and fi... Two-dimensional materials have a wide range of applications in many aspects due to their unique properties. Here we carry out a detailed structural search and design of the BP2using the first principles method, and find a new PMM2 sheet.The analysis of the phonon dispersive curves shows that the 2D PMM2 is dynamic stable. The study of molecular dynamics shows that the 2D PMM2 can be stable under high temperature, even at 600 K. Most importantly, when a suitable strain is applied, the structure can exhibit other electronic properties such as direct band gap semiconductor. In addition, the small strain can tune the band gap value of the PMM2 structure to around 1.4 e V, which is very close to the ideal band gap of solar materials. Therefore, the 2D PMM2 may have potential applications in the field of photovoltaic materials. 展开更多
关键词 two-dimensional material density functional theory direct band gap strain
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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 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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Effect of strain on structure and electronic properties of monolayer C_(4)N_(4)
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作者 陈昊 徐瑛 +1 位作者 赵家石 周丹 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期595-600,共6页
The first-principles calculations are performed to examine structural,mechanical,and electronic properties at large strain for a monolayer C_(4)N_(4),which has been predicted as an anchoring promising material to atte... The first-principles calculations are performed to examine structural,mechanical,and electronic properties at large strain for a monolayer C_(4)N_(4),which has been predicted as an anchoring promising material to attenuate shuttle effect in Li–S batteries stemming from its large absorption energy and low diffusion energy barrier.Our results show that the ideal strengths of C_(4)N_(4)under tension and pure shear deformation conditions reach 13.9 GPa and 12.5 GPa when the strains are 0.07 and 0.28,respectively.The folded five-membered rings and diverse bonding modes between carbon and nitrogen atoms enhance the ability to resist plastic deformation of C_(4)N_(4).The orderly bond-rearranging behaviors under the weak tensile loading path along the[100]direction cause the impressive semiconductor–metal transition and inverse semiconductor–metal transition.The present results enrich the knowledge of the structure and electronic properties of C_(4)N_(4)under deformations and shed light on exploring other two-dimensional materials under diverse loading conditions. 展开更多
关键词 two-dimensional materials strain effect structural evolution electronic properties
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心肌声学造影结合应变率成像技术评价急性心肌梗死PCI术后1年内再入院风险的临床价值
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作者 王俊伟 杜利军 +3 位作者 王旭 曾玲 申钊 侯博 《中西医结合心脑血管病杂志》 2025年第1期94-99,共6页
目的:探讨心肌声学造影(MCE)结合应变率成像技术(SRI)评价急性心肌梗死(AMI)经皮冠状动脉介入(PCI)术后1年内再入院风险的临床价值,以期为临床制定后续治疗方案、改善预后提供参考。方法:选取2020年12月—2022年12月我院185例AMI病人作... 目的:探讨心肌声学造影(MCE)结合应变率成像技术(SRI)评价急性心肌梗死(AMI)经皮冠状动脉介入(PCI)术后1年内再入院风险的临床价值,以期为临床制定后续治疗方案、改善预后提供参考。方法:选取2020年12月—2022年12月我院185例AMI病人作为研究对象,根据PCI术后1年内再入院率分为再入院组和非再入院组,统计两组术前、术后1年MCE定量参数[曲线斜率(β)、灌注计分指数(PSI)、平台期峰值强度(A)、心肌血流量(A·β)]、SRI定量参数[梗死心肌收缩期峰值纵向应变(LS)、变率(LSR-s)]、常规超声心动图参数[左室舒张末期内径(LVEDD)、左室收缩末期内径(LVESD)、左室射血分数(LVEF)],采用Pearson法分析MCE、SRI定量参数与常规超声心动图参数相关性,受试者工作特征(ROC)曲线分析MCE、SRI定量参数预测PCI术后1年内再入院风险,绘制决策曲线评估其应用临床时的获益情况,并通过临床影响曲线(CIC)评估各模型预测PCI术后1年内再入院的优劣。结果:术后1年再入院组PSI、梗死心肌LS及LSR-s高于非再入院组,A·β、A低于非再入院组,差值小于非再入院组(P<0.05);术后1年再入院组LVEF低于非再入院组,LVESD、LVEDD高于非再入院组,差值均小于非再入院组(P<0.05);PSI、A·β、A、β、梗死心肌LS及LSR-s与LVEF有相关性(P<0.05);MCE定量参数联合SRI定量参数预测AMI病人PCI术后1年内再入院的曲线下面积(AUC)为0.930,优于单一预测;经决策曲线分析(DCA)显示,阈值在0.0~1.0,联合MCE、SRI定量参数的预测模型预测结果优于单纯MCE定量参数和单纯SRI定量参数。结论:MCE结合SRI可用于AMI病人PCI术后1年内再入院风险评估中,临床可通过其进行早期预测再入院风险,以针对性展开后续治疗,降低再入院率。 展开更多
关键词 心肌声学造影 应变率成像技术 急性心肌梗死 经皮冠状动脉介入术 再入院风险 预测价值
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Small scale effects on buckling and postbuckling behaviors of axially loaded FGM nanoshells based on nonlocal strain gradient elasticity theory 被引量:8
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作者 S.SAHMANI A.M.FATTAHI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2018年第4期561-580,共20页
By means of a comprehensive theory of elasticity, namely, a nonlocal strain gradient continuum theory, size-dependent nonlinear axial instability characteristics of cylindrical nanoshells made of functionally graded m... By means of a comprehensive theory of elasticity, namely, a nonlocal strain gradient continuum theory, size-dependent nonlinear axial instability characteristics of cylindrical nanoshells made of functionally graded material(FGM) are examined. To take small scale effects into consideration in a more accurate way, a nonlocal stress field parameter and an internal length scale parameter are incorporated simultaneously into an exponential shear deformation shell theory. The variation of material properties associated with FGM nanoshells is supposed along the shell thickness, and it is modeled based on the Mori-Tanaka homogenization scheme. With a boundary layer theory of shell buckling and a perturbation-based solving process, the nonlocal strain gradient load-deflection and load-shortening stability paths are derived explicitly. It is observed that the strain gradient size effect causes to the increases of both the critical axial buckling load and the width of snap-through phenomenon related to the postbuckling regime, while the nonlocal size dependency leads to the decreases of them. Moreover, the influence of the nonlocal type of small scale effect on the axial instability characteristics of FGM nanoshells is more than that of the strain gradient one. 展开更多
关键词 nanomechanics functionally graded material(FGM) nonlocal strain gradient theory nonlinear instability perturbation technique
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Global Longitudinal Strain at Rest for Detection of Coronary Artery Disease in Patients without Diabetes Mellitus 被引量:6
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作者 Hou-juan ZUO Xiu-ting YANG +5 位作者 Qi-gong LIU Yan ZHANG He-song ZENG Jiang-tao YAN Dao-wen WANG Hong WANG 《Current Medical Science》 SCIE CAS 2018年第3期413-421,共9页
Global longitudinal strain (GLS) at rest on two-dimensional speckle tracking echocardiography (2D STE) was demonstrated to help detect coronary artery disease (CAD). However, the optimal cut-off point of GLS and... Global longitudinal strain (GLS) at rest on two-dimensional speckle tracking echocardiography (2D STE) was demonstrated to help detect coronary artery disease (CAD). However, the optimal cut-off point of GLS and its diagnostic power for detecting critical CAD in non-diabetes mellitus (DM) patients are unknown. In the present study, 211 patients with suspected CAD were prospectively included, with DM patients excluded. All patients underwent echocardiography and subsequently coronary angiography within 3 days. Left ventricular (LV) GLSs were quantified by 2D STE. Territorial peak systolic longitudinal strains (TLSs) were calculated based on the perfusion territories of the 3-epicardial coronary arteries in a 17-segment LV model. Critical CAD was defined as an area stenosis _〉70% in _〉1 epicardial coronary artery (_〉50% in left main coronary artery). Totally 145 patients were diagnosed as having critical CAD by coronary angiography. Significant differences were observed in all strain parameters between patients with and without critical CAD. The area under the receiver operating charcteristic (ROC) curve (AUC) for GLS in the detection of left main (LM) or threevessel CAD was 0.875 at a cut-off value of-19.05% with sensitivity of 78.1% and specificity of 72.7%, which increased to 0.926 after exclusion of apical segments (cut-off value -18.66%; sensitivity 84.4% and specificity 81.8%). The values of TLSs were significantly lower in regions supplied by stenotic arteries than in those by non-stenotic arteries. The AUC for the TLSs to identify critical stenosis of left circumflex (LCX) artery, left anterior descending (LAD) artery and right coronary artery (RCA), in order of diagnostic accuracy, was 0.818 for LCX, 0.764 for LAD and 0.723 for RCA, respectively. In conclusion, in non-DM patients with suspected CAD, GLS assessed by 2D STE is an excellent predictor for LM or three-vessel CAD with high diagnostic accuracy, and a higher cut-off point than reported before should be used. Excluding apical segments in the calculation of GLS can further improve the predictive accuracy of GLS. It is unsatisfactory for TLSs to be used to identify stenotic coronary arteries. 展开更多
关键词 two-dimensional strain coronary heart disease global longitudinal strain territorial longitudinal strain
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Proteomic Study on Two Bradyrhizobium japonicum Strains with Different Competitivenesses for Nodulation 被引量:3
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作者 LI Jun XIAO Wen-li +6 位作者 MA Ming-chao GUAN Da-wei JIANG Xin CAO Feng-ming SHEN De-long CHEN Hui-jun LI Li 《Agricultural Sciences in China》 CAS CSCD 2011年第7期1072-1079,共8页
Competitiveness for nodulation of Bradyrhizobium japonicum strains plays a key role in symbiotic nitrogen fixation. In order to reveal the difference in competitiveness, B. japonicum 4534 with high competitiveness and... Competitiveness for nodulation of Bradyrhizobium japonicum strains plays a key role in symbiotic nitrogen fixation. In order to reveal the difference in competitiveness, B. japonicum 4534 with high competitiveness and B. japonicum 4222 with low competitiveness for nodulation were analyzed by proteomic technique. The results showed that differential proteins were fewer when two strains were treated with just daidzein. Only 24 and 10 differential proteins were detected with an up-regulated rate of 58 and 40% in B. japonicum 4534 and B. japonicum 4222, respectively. However, more differential proteins were detected upon treatment with daidzein and mutual extracellular materials simultaneously. There were 78 differential proteins detected in B. japonicum 4534 with 43 being up-regulated and 35 being down-regulated. These differential proteins, such as metabolism-related proteins, transporters, transcription-related proteins, translation-related proteins, and flagellin, were found to be associated with nodulation process. 25 up-regulated and 22 down-regulated proteins were detected in B. japonicum 4222. Some of these proteins were not related to nodulation. More differential proteins associated with nodulation in B. japonicum 4534 may be the reason for its high competitiveness. The results can provide a guide to the selection and inoculation of effective strains and are significant to biological nitrogen fixation. 展开更多
关键词 Bradyrhizobium japonicum strains DAIDZEIN extracellular materials competitiveness for nodulation proteomic technique
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Isolation and identification of a bacteria strain Enterobacter cloacae I7 for degradation of hydrolyzed polyacrylamide 被引量:2
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作者 马放 李杰训 +3 位作者 魏利 陈忠喜 SHAIK FIRDOZ 赵光 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第5期669-672,共4页
A bacteria strain for the degradation of hydrolyzed polyacrylamide (HPAM) was isolated from a curing pot in HPAM distribution station of Daqing Oilfield using Hungate anaerobic technique. The isolate was investigate... A bacteria strain for the degradation of hydrolyzed polyacrylamide (HPAM) was isolated from a curing pot in HPAM distribution station of Daqing Oilfield using Hungate anaerobic technique. The isolate was investigated from morphological, physiological, biochemical and molecular characterization. It is a Gram-negative, shortbacillus, non-spore-forming anaerobic bacteria with an optimum growth at 8.0 pH at 40℃. It can reduce sulfate to I-I2S. Alignment of 16S ribosomal DNA and 16S-23S ribosomal DNA intergenic spacer sequences suggests that this isolate is closely related to the Enterobacter cloacae. The isolate is identified as a new strain belonging to Enterobacter genus, temporarily named as Enterobacter cloacae 17. Analysis results of infrared spectroscopy (IR) show that the bacteria can use HPAM as the only carbon source, change the structure of HPAM polymer surface, and realize the hydrolysis of amide to carboxyl group by hydrolysis mechanism. It can degrade the side chain and change some functional groups, which obviously decreases the viscosity. GC-MS analysis indicates that the determined low-molecular weight degradation products of HPAM are polyacrylamide fragments with duplet bond, epoxy as well as carbonyl group, but most of them are acrylamide oligomer derivatives. 展开更多
关键词 PAM-degrading bacteria strain Hungate anaerobic technique BIODEGRADATION Enterobacter cloacae I7
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Modulation of carrier lifetime in MoS2 monolayer by uniaxial strain 被引量:1
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作者 Hao Hong Yang Cheng +10 位作者 Chunchun Wu Chen Huang Can Liu Wentao Yu Xu Zhou Chaojie Ma Jinhuan Wang Zhihong Zhang Yun Zhao Jie Xiong Kaihui Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第7期182-187,共6页
Carrier lifetime is one of the most fundamental physical parameters that characterizes the average time of carrier recombination in any material.The control of carrier lifetime is the key to optimizing the device func... Carrier lifetime is one of the most fundamental physical parameters that characterizes the average time of carrier recombination in any material.The control of carrier lifetime is the key to optimizing the device function by tuning the electro-optical conversion quantum yield,carrier diffusion length,carrier collection process,etc.Till now,the prevailing modulation methods are mainly by defect engineering and temperature control,which have limitations in the modulation direction and amplitude of the carrier lifetime.Here,we report an effective modulation on the ultrafast dynamics of photoexcited carriers in two-dimensional(2D)MoS2 monolayer by uniaxial tensile strain.The combination of optical ultrafast pump-probe technique and time-resolved photoluminescence(PL)spectroscopy reveals that the carrier dynamics through Auger scattering,carrier-phonon scattering,and radiative recombination keep immune to the strain.But strikingly,the uniaxial tensile strain weakens the trapping of photoexcited carriers by defects and therefore prolongs the corresponding carrier lifetime up to 440%per percent applied strain.Our results open a new avenue to enlarge the carrier lifetime of 2D MoS2,which will facilitate its applications in high-efficient optoelectronic and photovoltaic devices. 展开更多
关键词 two-dimensional materials carrier dynamics strain trap states
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Strain drived band aligment transition of the ferromagnetic VS_(2)/C_(3)N van der Waals heterostructure 被引量:1
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作者 Jimin Shang Shuai Qiao +2 位作者 Jingzhi Fang Hongyu Wen Zhongming Wei 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第9期19-24,共6页
Exploring two-dimensional(2D)magnetic heterostructures is essential for future spintronic and optoelectronic devices.Herein,using first-principle calculations,stable ferromagnetic ordering and colorful electronic prop... Exploring two-dimensional(2D)magnetic heterostructures is essential for future spintronic and optoelectronic devices.Herein,using first-principle calculations,stable ferromagnetic ordering and colorful electronic properties are established by constructing the VS_(2)/C_(3)N van der Waals(vdW)heterostructure.Unlike the semiconductive properties with indirect band gaps in both the VS2 and C3N monolayers,our results indicate that a direct band gap with type-Ⅱband alignment and p-doping characters are realized in the spin-up channel of the VS_(2)/C_(3)N heterostructure,and a typical type-Ⅲband alignment with a broken-gap in the spin-down channel.Furthermore,the band alignments in the two spin channels can be effectively tuned by applying tensile strain.An interchangement between the type-Ⅱand type-Ⅲband alignments occurs in the two spin channels,as the tensile strain increases to 4%.The attractive magnetic properties and the unique band alignments could be useful for prospective applications in the next-generation tunneling devices and spintronic devices. 展开更多
关键词 two-dimensional ferromagnetic material van der Waals heterostructure band alignment strain
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Effects of Strain Channel on Electron Irradiation Tolerance of InP-based HEMT Structures
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作者 FANG Renfeng CAO Wenyu +6 位作者 WEI Yanfeng WANG Yin CHEN Chuanliang YAN Jiasheng XING Yan LIANG Guijie ZHOU Shuxing 《原子能科学技术》 EI CAS CSCD 北大核心 2023年第12期2288-2294,共7页
The introduction of strain In_(x)Ga_(1-x)As channel with high In content increases the confinement of the two-dimensional electron gas(2DEG)and further improves the high-frequency performance of InGaAs/InAlAs/InP HEMT... The introduction of strain In_(x)Ga_(1-x)As channel with high In content increases the confinement of the two-dimensional electron gas(2DEG)and further improves the high-frequency performance of InGaAs/InAlAs/InP HEMTs.The effect of In_(x)Ga_(1-x)As channel with different In contents on electron irradiation tolerance of InP-based HEMT structures in terms of 2DEG mobility and density has been investigated.The experiment results show that,after the same high electron irradiation dose,the 2DEG mobility and density in InP-based HEMT structures with strain In_(x)Ga_(1-x)As(x>0.53)channel decrease more dramatically than that without strain In_(0.53)Ga_(0.47)As channel.Moreover,the degradation of 2DEG mobility and density becomes more severe as the increase of In content and strain in the In_(x)Ga_(1-x)As channel.The research results can provide some suggestions for the design of radiation-resistant InP-based HEMTs. 展开更多
关键词 InP-based HEMT strain channel two-dimensional electron gas electron irradiation
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