目的:比较多回波合并梯度回波成像(multiple echo combined with two dimensional disturbed phase gradient echo,MEGRE)序列与脂肪抑制质子密度加权成像序列(fat-suppression proton density weighted imaging,FS-PDWI序列)在早期膝...目的:比较多回波合并梯度回波成像(multiple echo combined with two dimensional disturbed phase gradient echo,MEGRE)序列与脂肪抑制质子密度加权成像序列(fat-suppression proton density weighted imaging,FS-PDWI序列)在早期膝关节软骨损伤诊断中的应用价值。方法:选取2021年10月—2022年1月在重庆大学附属三峡医院就诊的100例骨性关节炎早期膝关节软骨损伤患者,采用GE1.5TMR成像系统进行多回波合并梯度回波成像和脂肪抑制质子密度加权成像,进行软骨损伤分级诊断,计算序列对膝关节软骨显示质量及损伤检出的准确度;Kappa一致性检验分析多回波合并梯度回波成像、脂肪抑制质子密度加权成像序列评分的一致性。结果:阅片者1评价200个图像序列中191个序列图像质量很好,9个序列图像质量一般;阅片者2评价188个序列图像质量很好,12个序列图像一般;MEGRE序列图像质量显著高于FS-PDWI序列(P <0.05)。MEGRE序列对膝关节软骨缺损程度分级的总体准确度和Kappa一致性分别为92.5%和92.4%。FS-PDWI序列对膝关节软骨缺损程度分级的总体准确度和Kappa一致性分别为80.0%和79.7%。结论:与FS-PDWI序列相比,MEGRE序列显示膝关节软骨图像质量更佳,对膝关节软骨缺损程度分级的总体准确度较高。MEGRE序列在膝关节软骨早期损伤的诊断上具有较高的应用价值。展开更多
A statistical multimodal background model was described for moving object detection in video surveillance. The solution to some of the problems such as illumination changes, initialization of model with moving objects...A statistical multimodal background model was described for moving object detection in video surveillance. The solution to some of the problems such as illumination changes, initialization of model with moving objects, and shadows suppression was provided. The background samples were chosen by thresholding inter-frame differences, and the Gaussian kernel density estimation was used to estimate the probability density function of background intensity. Pixel's neighbor information was considered to remove noise due to camera jitter and small motion in the scene. The hue-max-min-diff color information was used to detect and suppress moving cast shadows. The effectiveness of the proposed method in the foreground segmentation was demonstrated in the traffic surveillance application.展开更多
Cancer is one of the most serious issues in human life.Blocking programmed cell death protein 1 and programmed death ligand-1(PD-L1)pathway is one of the great innovations in the last few years,a few numbers of inhibi...Cancer is one of the most serious issues in human life.Blocking programmed cell death protein 1 and programmed death ligand-1(PD-L1)pathway is one of the great innovations in the last few years,a few numbers of inhibitors can be able to block it.(2-Methyl-3-biphenylyl)methanol derivative is one of them.Here,the quantitative structure-activity relationship(QSAR)established twenty(2-methyl-3-biphenylyl)methanol derivatives as the programmed death ligand-1 inhibitors.Density functional theory at the B3LPY/6-31+G(d,p)level was employed to study the chemical structure and properties of the chosen compounds.Highest occupied molecular orbital energy EHOMO,lowest unoccupied molecular orbital energy ELUMO,total energy ET,dipole moment DM,absolute hardnessη,absolute electronegativityχ,softness S,electrophilicityω,energy gap?E,etc.,were observed and determined.Principal component analysis(PCA),multiple linear regression(MLR)and multiple nonlinear regression(MNLR)analysis were carried out to establish the QSAR.The proposed quantitative models and interpreted outcomes of the compounds were based on statistical analysis.Statistical results of MLR and MNLR exhibited the coefficient R^2 was 0.661 and 0.758,respectively.Leave-one-out cross-validation,r_m^2 metric,r_m^2 test,and"Golbraikh&Tropsha’s criteria"analyses were applied for the validation of MLR and MNLR,which indicate two models are statistically significant and well stable with data variation in the external validation towards PD-L1.The obtained results showed that the MNLR model predicts the bioactivity more accurately than MLR,and it may be helpful and supporting for evaluation of the biological activity of PD-L1 inhibitors.展开更多
Objective： The aim of this study was to compare effect of rh-endostatin on microvasculature in tumor and myocardium tissue. Methods： Nude mice were randomized into 4 groups, blank control group [did not burden tumor...Objective： The aim of this study was to compare effect of rh-endostatin on microvasculature in tumor and myocardium tissue. Methods： Nude mice were randomized into 4 groups, blank control group [did not burden tumor, normalsaline （NS） 100 μL/d], drug control group （did not burden tumor, rh-endostatin 400 μg/d）, model group （mice burdened tumor, NS 100 μL/d） and treatment group （mice burdened tumor, rh-endostatin 400 μg/d）, administration was given during d1-d28. The volume of tumor and the weight of mouse were measured before and after administration. The expression of CD34, MMP-2, MMP-9, HIF-la and VEGF in myocardium and tumor were detected by immunohistochemistry. The structure of vasculature was observed by immunoenzymatic double staining with CD34 and Masson. Results： The tumor volume increase of treatment group （48.18 mm3） was less than the model group （113.80 mm3）, the change of weight was not significant among the four groups. After treated with endotar, the expression of MMP-9 and VEGF in tumor were obviously down-regulated, but the same results was not found in MMP-2, HIF-la of tumor. MVD in tumor of treatment group decreased significantly compared with model group. Proportion of tumor vessels covered by collagen in treatment group increased compared with model group. However, MVD and microvasculature in myocardium did not change significantly. Conclusion： Rh-endostatin can decrease the expression of MMP-9, VEGF and MVD to inhibit growth of tumor and normalize micrangium in tumor but cannot weaken MMPs and MVD of mature micrangium in myocardium.展开更多
Inflatable space structures may undergo the vibration of a long duration because of their features of dynamic deployment,high flexibility,and low-frequency modes.In this paper,a topology optimization methodology is pr...Inflatable space structures may undergo the vibration of a long duration because of their features of dynamic deployment,high flexibility,and low-frequency modes.In this paper,a topology optimization methodology is proposed to reduce the vibration of a spinning inflatable structure.As the first step,a variable-length shell element is developed in the framework of arbitrary Lagrange-Euler(ALE)and absolute nodal coordinate formulation(ANCF)to accurately model the deployment dynamics of the inflatable structure.With the help of two additional material coordinates,the shell element of ALE-ANCF has the ability to describe the large deformation,large overall motion,and variable length of an inflatable structure.The nonlinear elastic forces and additional inertial forces induced by the variable length are analytically derived.In the second step,a topology optimization procedure is presented for the dynamic response of an inflatable structure through the integration of the equivalent static loads(ESL)method and the density method.The ESL sets of the variable-length inflatable structure are defined to simplify the dynamic topology optimization into a static one,while the density-based topology optimization method is used to describe the topology of the inflatable structure made of two materials and solve the static optimization problem.In order to obtain more robust optimization results,sensitivity analysis,density filter,and projection techniques are also utilized.Afterwards,a benchmark example is presented to validate the ALE-ANCF modeling scheme.The deployment dynamics and corresponding topology optimization of a spinning inflatable structure are studied to show the effectiveness of the proposed topology optimization methodology.展开更多
文摘目的:比较多回波合并梯度回波成像(multiple echo combined with two dimensional disturbed phase gradient echo,MEGRE)序列与脂肪抑制质子密度加权成像序列(fat-suppression proton density weighted imaging,FS-PDWI序列)在早期膝关节软骨损伤诊断中的应用价值。方法:选取2021年10月—2022年1月在重庆大学附属三峡医院就诊的100例骨性关节炎早期膝关节软骨损伤患者,采用GE1.5TMR成像系统进行多回波合并梯度回波成像和脂肪抑制质子密度加权成像,进行软骨损伤分级诊断,计算序列对膝关节软骨显示质量及损伤检出的准确度;Kappa一致性检验分析多回波合并梯度回波成像、脂肪抑制质子密度加权成像序列评分的一致性。结果:阅片者1评价200个图像序列中191个序列图像质量很好,9个序列图像质量一般;阅片者2评价188个序列图像质量很好,12个序列图像一般;MEGRE序列图像质量显著高于FS-PDWI序列(P <0.05)。MEGRE序列对膝关节软骨缺损程度分级的总体准确度和Kappa一致性分别为92.5%和92.4%。FS-PDWI序列对膝关节软骨缺损程度分级的总体准确度和Kappa一致性分别为80.0%和79.7%。结论:与FS-PDWI序列相比,MEGRE序列显示膝关节软骨图像质量更佳,对膝关节软骨缺损程度分级的总体准确度较高。MEGRE序列在膝关节软骨早期损伤的诊断上具有较高的应用价值。
文摘A statistical multimodal background model was described for moving object detection in video surveillance. The solution to some of the problems such as illumination changes, initialization of model with moving objects, and shadows suppression was provided. The background samples were chosen by thresholding inter-frame differences, and the Gaussian kernel density estimation was used to estimate the probability density function of background intensity. Pixel's neighbor information was considered to remove noise due to camera jitter and small motion in the scene. The hue-max-min-diff color information was used to detect and suppress moving cast shadows. The effectiveness of the proposed method in the foreground segmentation was demonstrated in the traffic surveillance application.
基金National Natural Science Foundation of China(31360371)the Key Research and Development Project of Jiangxi Province(20181BBH80010,20192ZDF04032,20202BBF63012)The Science Foundation of the Education Department of Jiangxi Province(GJJ201821,GJJ 180918)。
文摘实验室前期研究结果表明,在国家规定的药食两用物品名单中,丁香抗氧化活性最强。前人发现天然产物的抗氧化功能与抗糖基化活性息息相关。因此,目的是在此基础上进一步对丁香精油(clove essential oil,CEO)的抗糖基化活性及其中含量最高的组分—丁香酚(Eugenol)与牛血清白蛋白(bovine serum albumin,BSA)的相互作用进行研究。在低密度脂蛋白(low density lipoprotein,LDL)的非酶糖基化孵育体系中,光谱测定结果表明CEO对LDL糖基化早期、中期和末期产物的生成均具有显著的抑制效果,且对末期产物的抑制作用最强。采用气相色谱-质谱联用技术(gas chromatography mass spectrometry,GC-MS)对CEO分析发现,CEO中含量最多的组分是丁香酚。通过多光谱和分子对接对丁香酚与BSA的相互作用研究发现,紫外-可见(ultraviolet-visible,UV-Vis)光谱表明丁香酚与BSA之间存在相互作用;在荧光发射光谱中,随着丁香酚浓度增加,BSA的荧光强度逐渐增强且发生蓝移,进一步证明了二者之间存在相互作用。通过计算不同温度下的结合常数发现,丁香酚与BSA产生相互作用过程中有热力学过程参与,热力学参数和位点标记竞争试验表明丁香酚通过氢键和范德华力与BSA在位点Ⅰ结合。随着丁香酚浓度增加,丁香酚与BSA混合体系的同步荧光(synchronous fluorescence,SF)、三维荧光(three-dimensional,3D)和傅里叶变换红外(Fourier transform infrared,FTIR)光谱的信号强度在发生变化的同时也发生了位移,表明丁香酚的添加使BSA构象发生了改变。通过分子对接技术进一步验证了丁香酚与BSA间相互作用的试验结果。该研究为丁香进一步开发应用提供理论支持。
基金the Natural Science Foundation of Jiangsu Province(BK20181128)333 Project of Jiangsu Province(BRA2016518)Jiangsu Provincial Medical Youth Talent(QNRC2016626)。
文摘Cancer is one of the most serious issues in human life.Blocking programmed cell death protein 1 and programmed death ligand-1(PD-L1)pathway is one of the great innovations in the last few years,a few numbers of inhibitors can be able to block it.(2-Methyl-3-biphenylyl)methanol derivative is one of them.Here,the quantitative structure-activity relationship(QSAR)established twenty(2-methyl-3-biphenylyl)methanol derivatives as the programmed death ligand-1 inhibitors.Density functional theory at the B3LPY/6-31+G(d,p)level was employed to study the chemical structure and properties of the chosen compounds.Highest occupied molecular orbital energy EHOMO,lowest unoccupied molecular orbital energy ELUMO,total energy ET,dipole moment DM,absolute hardnessη,absolute electronegativityχ,softness S,electrophilicityω,energy gap?E,etc.,were observed and determined.Principal component analysis(PCA),multiple linear regression(MLR)and multiple nonlinear regression(MNLR)analysis were carried out to establish the QSAR.The proposed quantitative models and interpreted outcomes of the compounds were based on statistical analysis.Statistical results of MLR and MNLR exhibited the coefficient R^2 was 0.661 and 0.758,respectively.Leave-one-out cross-validation,r_m^2 metric,r_m^2 test,and"Golbraikh&Tropsha’s criteria"analyses were applied for the validation of MLR and MNLR,which indicate two models are statistically significant and well stable with data variation in the external validation towards PD-L1.The obtained results showed that the MNLR model predicts the bioactivity more accurately than MLR,and it may be helpful and supporting for evaluation of the biological activity of PD-L1 inhibitors.
基金Supported by grants from the Tianjin Medical University Research Projects(2009KY37)CSCO Vascular Target Fund Research Projects of Roche(Y-X2011-001)
文摘Objective： The aim of this study was to compare effect of rh-endostatin on microvasculature in tumor and myocardium tissue. Methods： Nude mice were randomized into 4 groups, blank control group [did not burden tumor, normalsaline （NS） 100 μL/d], drug control group （did not burden tumor, rh-endostatin 400 μg/d）, model group （mice burdened tumor, NS 100 μL/d） and treatment group （mice burdened tumor, rh-endostatin 400 μg/d）, administration was given during d1-d28. The volume of tumor and the weight of mouse were measured before and after administration. The expression of CD34, MMP-2, MMP-9, HIF-la and VEGF in myocardium and tumor were detected by immunohistochemistry. The structure of vasculature was observed by immunoenzymatic double staining with CD34 and Masson. Results： The tumor volume increase of treatment group （48.18 mm3） was less than the model group （113.80 mm3）, the change of weight was not significant among the four groups. After treated with endotar, the expression of MMP-9 and VEGF in tumor were obviously down-regulated, but the same results was not found in MMP-2, HIF-la of tumor. MVD in tumor of treatment group decreased significantly compared with model group. Proportion of tumor vessels covered by collagen in treatment group increased compared with model group. However, MVD and microvasculature in myocardium did not change significantly. Conclusion： Rh-endostatin can decrease the expression of MMP-9, VEGF and MVD to inhibit growth of tumor and normalize micrangium in tumor but cannot weaken MMPs and MVD of mature micrangium in myocardium.
基金the National Natural Science Foundation of China(Grant Nos.12002153,11827801,and 11832005)the Natural Science Foundation of Jiangsu Province(Grant No.BK20200434)the Fundamental Research Funds for the Central Universities(Grant No.NS2021003).
文摘Inflatable space structures may undergo the vibration of a long duration because of their features of dynamic deployment,high flexibility,and low-frequency modes.In this paper,a topology optimization methodology is proposed to reduce the vibration of a spinning inflatable structure.As the first step,a variable-length shell element is developed in the framework of arbitrary Lagrange-Euler(ALE)and absolute nodal coordinate formulation(ANCF)to accurately model the deployment dynamics of the inflatable structure.With the help of two additional material coordinates,the shell element of ALE-ANCF has the ability to describe the large deformation,large overall motion,and variable length of an inflatable structure.The nonlinear elastic forces and additional inertial forces induced by the variable length are analytically derived.In the second step,a topology optimization procedure is presented for the dynamic response of an inflatable structure through the integration of the equivalent static loads(ESL)method and the density method.The ESL sets of the variable-length inflatable structure are defined to simplify the dynamic topology optimization into a static one,while the density-based topology optimization method is used to describe the topology of the inflatable structure made of two materials and solve the static optimization problem.In order to obtain more robust optimization results,sensitivity analysis,density filter,and projection techniques are also utilized.Afterwards,a benchmark example is presented to validate the ALE-ANCF modeling scheme.The deployment dynamics and corresponding topology optimization of a spinning inflatable structure are studied to show the effectiveness of the proposed topology optimization methodology.
