BACKGROUND Dry eye is a common eye disease.Artificial tears supplements are widely used for the treatment of dry eyes.However,multiple adverse effects have been observed in patients receiving long-term treatment with ...BACKGROUND Dry eye is a common eye disease.Artificial tears supplements are widely used for the treatment of dry eyes.However,multiple adverse effects have been observed in patients receiving long-term treatment with artificial tears,which may affect the therapeutic effect.AIM To analyze the characteristics of interleukin-1β(IL-1β),interleukin-6(IL-6),and tumor necrosis factor-alpha(TNF-α)levels in patients with dry eye and the therapeutic effect of artificial tears combined with cyclosporine A.METHODS A total of 124 dry eye patients treated at The First People’s Hospital of Xining from April 2020 to April 2022 were selected as the observation group,while 20 healthy individuals served as the control group during the same period.Levels of inflammatory markers,including IL-1β,IL-6,and TNF-α,were analyzed.The observation group was further divided into a study group and a control group,each consisting of 62 patients.The control group received artificial tears,whereas the study group received a combination of artificial tears and cyclosporine A.Inflammatory markers,Schirmer’s test(SIT),tear break-up time(TBUT),corneal fluorescein staining(CFS),National Eye Institute Visual Function Questionnaire-25(NEI-VFQ-25)scores,and adverse events(AEs)were compared between the two groups.RESULTS The observation group exhibited significantly elevated serum levels of IL-1β,IL-6,and TNF-αin comparison to the healthy group.Following treatment,the study group demonstrated substantial reductions in IL-1β,IL-6,and TNF-αlevels relative to the control group.Moreover,after treatment,the study group experienced a marked decrease in CFS scores and significant increases in both SIT and BUT levels when compared to the control group.Additionally,significant improvements were observed in the primary symptom of dry eye and secondary symptoms such as photophobia,foreign body sensation,fatigue,red eye,and burning sensation within the study group.Furthermore,post-treatment NEI-VFQ-25 scores across all dimensions exhibited significant enhancements in the study group compared to the control group(P<0.05).It is noteworthy that significant AEs were reported in both groups throughout the treatment period.CONCLUSION Cyclosporine A combined with artificial tears is effective in treating dry eye,yielding enhanced outcomes by improving SIT and TBUT levels,reducing CFS scores,and ameliorating vision-related quality of life.展开更多
The depression-like behavior phenotype,neurogenesis in the dentate gyrus and miR-124 expression in the hippocampus are the focus of current research on the pathogenesis of depression and antidepressant therapy.The pre...The depression-like behavior phenotype,neurogenesis in the dentate gyrus and miR-124 expression in the hippocampus are the focus of current research on the pathogenesis of depression and antidepressant therapy.The present study aimed to clarify the dynamic changes of depression-like behavior,dentate gyrus neurogenesis and hippocampal miR-124 expression during depression induced by chronic stress to reveal pathological features at different stages of depression and to further provide insight into depression treatment.Chronic unpredictable mild stress depression models were established by exposing Sprague-Dawley rats to various mild stressors,including white noise,thermal swimming,stroboscopic illumination,soiled cages,pairing with three other stressed animals,cold swimming,tail pinch,restraint and water and food deprivation.Chronic unpredictable mild stress model rats underwent dynamic observation from 1 to 8 weeks and were compared with a control group(normal feeding without any stressors).To observe changes in the depression-like behavior phenotype during chronic unpredictable mild stress-induced depression,a sucrose preference test was used to evaluate the degree of anhedonia.An open-field test was used to evaluate locomotor activity and anxiety status.Compared with the control group,chronic unpredictable mild stress rats lost weight but did not have a depression-like behavioral phenotype at 1-4 weeks.Chronic unpredictable mild stress rats presented decreased sucrose preference and locomotor activity at 5-8 weeks.In addition,chronic unpredictable mild stress rats did not have significant anxiety-like behavior during 1-8 weeks of modeling.To observe neurogenesis dysfunctions and changes in neuronal number in the dentate gyrus during chronic unpredictable mild stress-induced depression,markers(DCX and DCX/BrdU)of neural proliferation and differentiation and the neuronal marker NeuN were assessed by immunofluorescence.Compared with the control group,neurogenesis and the neuronal number in the dentate gyrus did not change from 2 to 6 weeks;however,neural proliferation and differentiation in the dentate gyrus decreased,and the number of neurons decreased until the eighth week in the chronic unpredictable mild stress group.Real-time quantitative reverse transcription polymerase chain reaction assays and fluorescence in situ hybridization were used to measure the expression of hippocampal miR-124 during chronic unpredictable mild stress-induced depression.The results showed that the expression of hippocampal miR-124 was unchanged during the first 4 weeks but increased from 5 to 6 weeks and decreased from 7 to 8 weeks compared with the control group.These findings indicate that during chronic unpredictable mild stress-induced depression,the behavioral phenotype,miR-124 expression in the hippocampus,neurogenesis in the dentate gyrus and neuronal numbers showed dynamic changes,which suggested that various pathological changes occur at different stages of depression.All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Guangzhou University of Chinese Medicine of China in March 2015.展开更多
Imaging the spatial precession cone-shaped targets with narrowband radar is a new technical approach in mid-course recognition problem. However, most existing time-frequency methods still have some inevitable deficien...Imaging the spatial precession cone-shaped targets with narrowband radar is a new technical approach in mid-course recognition problem. However, most existing time-frequency methods still have some inevitable deficiencies for extracting microDoppler information in practical applications, which leads to blurring of the image. A new narrowband radar imaging algorithm for the precession cone-shaped targets is proposed. The instantaneous frequency of each scattering point is gained by using the improved Hilbert-Huang transform, then the positions of scattering points in the parameter domain are reconstructed. Numerical simulation and experiment results confirm the effectiveness and high precision of the proposed algorithm.展开更多
Paralytic shellfi sh poisoning(PSP)microalgae,as one of the harmful algal blooms,causes great damage to the of fshore fi shery,marine culture,and marine ecological environment.At present,there is no technique for real...Paralytic shellfi sh poisoning(PSP)microalgae,as one of the harmful algal blooms,causes great damage to the of fshore fi shery,marine culture,and marine ecological environment.At present,there is no technique for real-time accurate identifi cation of toxic microalgae,by combining three-dimensional fluorescence with machine learning(ML)and deep learning(DL),we developed methods to classify the PSP and non-PSP microalgae.The average classifi cation accuracies of these two methods for microalgae are above 90%,and the accuracies for discriminating 12 microalgae species in PSP and non-PSP microalgae are above 94%.When the emission wavelength is 650-690 nm,the fl uorescence characteristics bands(excitation wavelength)occur dif ferently at 410-480 nm and 500-560 nm for PSP and non-PSP microalgae,respectively.The identification accuracies of ML models(support vector machine(SVM),and k-nearest neighbor rule(k-NN)),and DL model(convolutional neural network(CNN))to PSP microalgae are 96.25%,96.36%,and 95.88%respectively,indicating that ML and DL are suitable for the classifi cation of toxic microalgae.展开更多
We used resting-state functional magnetic resonance imaging(fMRI)to determine whether there are any abnormalities in different frequency bands between amplitude of low-frequency fluctuations(ALFF)and fractional ALFF(f...We used resting-state functional magnetic resonance imaging(fMRI)to determine whether there are any abnormalities in different frequency bands between amplitude of low-frequency fluctuations(ALFF)and fractional ALFF(fALFF)and between 10 early amnestic mild cognitive impairment(EMCI)patients and eight normal controls participating in the Alzheimer’s Disease Neuroimaging Initiative(ADNI).We showed widespread difference in ALFF/fALFF between two frequency bands(slow-4:0.027-0.073 Hz,slow-5:0.01-0.027 Hz)in many brain areas including posterior cingulate cortex(PCC),medial prefrontal cortex(MPFC),suprasellar cistern(SC)and ambient cistern(AC).Compared to the normal controls,the EMCI patients showed increased ALFF values in PCu,cerebellum,occipital lobe and cerebellum posterior lobe in frequency band slow-4.While in frequency band slow-5,the EMCI patients showed decreased ALFF values in temporal lobe,left cerebrum and middle temporal gyrus5.Moreover,the EMCI patients showed increased fALFF values in frontal lobe and inferior frontal gyrus in band slow-5.While in frequency band slow-4,the EMCI patients showed decreased fALFF values in limbic lobe,cingulate gyrus and corpus callosum.These results demonstrated that EMCI patients had widespread abnormalities of amplitude of LFF in different frequency bands.展开更多
Implantable system maximizes drug concentration and continuously releases drugs near the tumor,which is an effective tool to solve the difficult retention of chemotherapy drugs in bladder cancer.In this work,a novel p...Implantable system maximizes drug concentration and continuously releases drugs near the tumor,which is an effective tool to solve the difficult retention of chemotherapy drugs in bladder cancer.In this work,a novel polysaccharide supramolecular injectable hydrogel(CCA hydrogels for short)is rapidly constructed by simply mixing cationic chitosan,anionic sulfobutyl etherβ-cyclodextrin(SBE-β-CD)and a trace amount of silver ions.The injected hydrogel reconstituted and regained its shape in less than 1 h,and it can still maintain the elasticity suitable for the human body.By packaging the drug directly,the gel achieves a high concentration of doxorubicin,an anticancer drug.Using MB49-luc cells as the model of bladder tumor for anti-tumor in vivo,the CCA-DOX gel has obvious inhibitory effect on bladder tumor,and its inhibitory effect is much greater than that of free DOX.Therefore,this self-healing injectable hydrogel has great potential for in situ treatment of bladder cancer.展开更多
In recent years,multicolor cascade supramolecular assemblies with controllable topological morphology have become a research hotspot due to their wide application in light-emitting materials,cell imaging and other fie...In recent years,multicolor cascade supramolecular assemblies with controllable topological morphology have become a research hotspot due to their wide application in light-emitting materials,cell imaging and other fields.Herein,several kinds of macrocycles including cucurbiturils,calixarene and cyclodextrins are used as building blocks to construct fluorescent assemblies with anthryl-conjugated phenylpyridine(G),wherein cucurbit[8]uril(CB[8])and G can form nanowires at a stoichiometric ratio of n:n through host-guest encapsulation to form a non-covalent heterodimer.Significantly,the macrocycle confinement effect drastically enhances the fluorescence emission of G and emission peak generated bathochromic shift from 500 nm to 600 nm.When the supramolecular polymer is further assembled with amphiphilic calix[4]arene(SC_(4)A8),the fluorescence emission of G?CB[8]further increases to 1.4 times,accompanied by the morphological transformation from linear structure to nanorod structure.Subsequently,a very small amount of dye Cy5 is added to the assembly solution as an energy receptor,and the negatively charged G?CB[8]@SC_(4)A8 system is regarded as an energy donor.The efficient energy transfer process enables near-infrared(NIR)emission at 675 nm with 71%energy transfer efficiency(ΦET)at a donor/receptor ratio of 100:1.Finally,the cascade supramolecular assembly has been successfully applied to targeted imaging in the nucleus of HeLa and A549 cancer cells.展开更多
Time domain analysis is an essential implement to study the buffeting behavior of long-span bridges for it can consider the non-linear effect which is significant in long-span bridges. The prerequisite of time domain ...Time domain analysis is an essential implement to study the buffeting behavior of long-span bridges for it can consider the non-linear effect which is significant in long-span bridges. The prerequisite of time domain analysis is the accurate description of 3D turbulence winds. In this paper, some hypotheses for simplifying the 3D turbulence simulation of long-span cable-stayed bridges are conducted, considering the structural characteristics. The turbulence wind which is a 3D multivariate stochastic vector process is converted into four independent 1D univariate stochastic processes. Based on recorded wind data from structural health monitoring system (SHMS) of the Sutong Bridge, China, the measured spectra expressions are then presented using the nonlinear least-squares fitting method. Turbulence winds at the Sutong Bridge site are simulated based on the spectral representation method and the Fast Fourier transform (FFT) technique, and the relevant results derived from target spectra including measured spectra and recommended spectra are compared. The reliability and accuracy of the presented turbulence simulation method are validated through comparisons between simulated and target spectra (measured and recommended spectra). The obtained turbulence si-mulations can not only serve further analysis of the buffeting behavior of the Sutong Bridge, but references for structural anti-wind design in adjacent regions.展开更多
In the engineering practice, merging statistical analysis into structural evaluation and assessment is a tendency in the future. As a combination of mathematical and statistical techniques, response surface (RS) met...In the engineering practice, merging statistical analysis into structural evaluation and assessment is a tendency in the future. As a combination of mathematical and statistical techniques, response surface (RS) methodology has been successfully applied to design optimization, response prediction and model validation. With the aid of RS methodology, these two serial papers present a finite element (FE) model updating and validation method for bridge structures based on structural health monitoring. The key issues to implement such a model updating are discussed in this paper, such as design of experiment, parameter screening, construction of high-order polynomial response surface model, optimization methods and precision inspection of RS model. The proposed procedure is illustrated by a prestressed concrete continuous rigid-frame bridge monitored under operational conditions. The results from the updated FE model have been compared with those obtained from online health monitoring system. The real application to a full-size bridge has demonstrated that the FE model updating process is efficient and convenient. The updated FE model can relatively reflect the actual condition of Xiabaishi Bridge in the design space of parameters and can be further applied to FE model validation and damage identification.展开更多
Because of uncertainties involved in modeling, construction, and measurement systems, the assessment of the FE model validation must be conducted based on stochastic mea- surements to provide designers with confidence...Because of uncertainties involved in modeling, construction, and measurement systems, the assessment of the FE model validation must be conducted based on stochastic mea- surements to provide designers with confidence for further applications. In this study, based on the updated model using response surface methodology, a practical model vali- dation methodology via uncertainty propagation is presented. Several criteria of testing/ analysis correlation are introduced, and the sources of model and testing uncertainties are also discussed. After that, Monte Carlo stochastic finite element (FE) method is employed to perform the uncertainty quantification and propagation. The proposed methodology is illustrated with the examination of the validity of a large-span prestressed concrete continuous rigid frame bridge monitored under operational conditions. It can be concluded that the calculated frequencies and vibration modes of the updated FE model of Xiabaishi Bridge are consistent with the measured ones. The relative errors of each frequency are all less than 3.7%. Meanwhile, the overlap ratio indexes of each frequency are all more than 75%; The MAC values of each calculated vibration frequency are all more than 90%. The model of Xiabaishi Bridge is valid in the whole operation space including experimental design space, and its confidence level is upper than 95%. The validated FE model of Xia- baishi Bridge can reflect the current condition of Xiabaishi Bridge, and also can be used as basis of bridge health monitoring, damage identification and safety assessment.展开更多
文摘BACKGROUND Dry eye is a common eye disease.Artificial tears supplements are widely used for the treatment of dry eyes.However,multiple adverse effects have been observed in patients receiving long-term treatment with artificial tears,which may affect the therapeutic effect.AIM To analyze the characteristics of interleukin-1β(IL-1β),interleukin-6(IL-6),and tumor necrosis factor-alpha(TNF-α)levels in patients with dry eye and the therapeutic effect of artificial tears combined with cyclosporine A.METHODS A total of 124 dry eye patients treated at The First People’s Hospital of Xining from April 2020 to April 2022 were selected as the observation group,while 20 healthy individuals served as the control group during the same period.Levels of inflammatory markers,including IL-1β,IL-6,and TNF-α,were analyzed.The observation group was further divided into a study group and a control group,each consisting of 62 patients.The control group received artificial tears,whereas the study group received a combination of artificial tears and cyclosporine A.Inflammatory markers,Schirmer’s test(SIT),tear break-up time(TBUT),corneal fluorescein staining(CFS),National Eye Institute Visual Function Questionnaire-25(NEI-VFQ-25)scores,and adverse events(AEs)were compared between the two groups.RESULTS The observation group exhibited significantly elevated serum levels of IL-1β,IL-6,and TNF-αin comparison to the healthy group.Following treatment,the study group demonstrated substantial reductions in IL-1β,IL-6,and TNF-αlevels relative to the control group.Moreover,after treatment,the study group experienced a marked decrease in CFS scores and significant increases in both SIT and BUT levels when compared to the control group.Additionally,significant improvements were observed in the primary symptom of dry eye and secondary symptoms such as photophobia,foreign body sensation,fatigue,red eye,and burning sensation within the study group.Furthermore,post-treatment NEI-VFQ-25 scores across all dimensions exhibited significant enhancements in the study group compared to the control group(P<0.05).It is noteworthy that significant AEs were reported in both groups throughout the treatment period.CONCLUSION Cyclosporine A combined with artificial tears is effective in treating dry eye,yielding enhanced outcomes by improving SIT and TBUT levels,reducing CFS scores,and ameliorating vision-related quality of life.
基金supported by the National Natural Science Foundation of China,No.81573858(to LLW)the Natural Science Foundation of Guangdong Province of China,No.2016A030313648(to CY)the Major Basic Research Project of Educational Commission of Guangdong Province of China,No.2017KZDXM020(to CY)
文摘The depression-like behavior phenotype,neurogenesis in the dentate gyrus and miR-124 expression in the hippocampus are the focus of current research on the pathogenesis of depression and antidepressant therapy.The present study aimed to clarify the dynamic changes of depression-like behavior,dentate gyrus neurogenesis and hippocampal miR-124 expression during depression induced by chronic stress to reveal pathological features at different stages of depression and to further provide insight into depression treatment.Chronic unpredictable mild stress depression models were established by exposing Sprague-Dawley rats to various mild stressors,including white noise,thermal swimming,stroboscopic illumination,soiled cages,pairing with three other stressed animals,cold swimming,tail pinch,restraint and water and food deprivation.Chronic unpredictable mild stress model rats underwent dynamic observation from 1 to 8 weeks and were compared with a control group(normal feeding without any stressors).To observe changes in the depression-like behavior phenotype during chronic unpredictable mild stress-induced depression,a sucrose preference test was used to evaluate the degree of anhedonia.An open-field test was used to evaluate locomotor activity and anxiety status.Compared with the control group,chronic unpredictable mild stress rats lost weight but did not have a depression-like behavioral phenotype at 1-4 weeks.Chronic unpredictable mild stress rats presented decreased sucrose preference and locomotor activity at 5-8 weeks.In addition,chronic unpredictable mild stress rats did not have significant anxiety-like behavior during 1-8 weeks of modeling.To observe neurogenesis dysfunctions and changes in neuronal number in the dentate gyrus during chronic unpredictable mild stress-induced depression,markers(DCX and DCX/BrdU)of neural proliferation and differentiation and the neuronal marker NeuN were assessed by immunofluorescence.Compared with the control group,neurogenesis and the neuronal number in the dentate gyrus did not change from 2 to 6 weeks;however,neural proliferation and differentiation in the dentate gyrus decreased,and the number of neurons decreased until the eighth week in the chronic unpredictable mild stress group.Real-time quantitative reverse transcription polymerase chain reaction assays and fluorescence in situ hybridization were used to measure the expression of hippocampal miR-124 during chronic unpredictable mild stress-induced depression.The results showed that the expression of hippocampal miR-124 was unchanged during the first 4 weeks but increased from 5 to 6 weeks and decreased from 7 to 8 weeks compared with the control group.These findings indicate that during chronic unpredictable mild stress-induced depression,the behavioral phenotype,miR-124 expression in the hippocampus,neurogenesis in the dentate gyrus and neuronal numbers showed dynamic changes,which suggested that various pathological changes occur at different stages of depression.All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Guangzhou University of Chinese Medicine of China in March 2015.
基金supported by the China National Funds for Distinguished Young Scientists(61025006)
文摘Imaging the spatial precession cone-shaped targets with narrowband radar is a new technical approach in mid-course recognition problem. However, most existing time-frequency methods still have some inevitable deficiencies for extracting microDoppler information in practical applications, which leads to blurring of the image. A new narrowband radar imaging algorithm for the precession cone-shaped targets is proposed. The instantaneous frequency of each scattering point is gained by using the improved Hilbert-Huang transform, then the positions of scattering points in the parameter domain are reconstructed. Numerical simulation and experiment results confirm the effectiveness and high precision of the proposed algorithm.
基金Supported by the National Natural Science Foundation of China(No.41972244)partially supported by the Science and Technology Basic Resources Survey of the Ministry of Science and Technology(No.2018FY100201)+3 种基金the National Key Research and Development Program(No.2019YFC1407900)to Siyu GOUShuai ZHANGWenyu GANand Tianjiu JIANG。
文摘Paralytic shellfi sh poisoning(PSP)microalgae,as one of the harmful algal blooms,causes great damage to the of fshore fi shery,marine culture,and marine ecological environment.At present,there is no technique for real-time accurate identifi cation of toxic microalgae,by combining three-dimensional fluorescence with machine learning(ML)and deep learning(DL),we developed methods to classify the PSP and non-PSP microalgae.The average classifi cation accuracies of these two methods for microalgae are above 90%,and the accuracies for discriminating 12 microalgae species in PSP and non-PSP microalgae are above 94%.When the emission wavelength is 650-690 nm,the fl uorescence characteristics bands(excitation wavelength)occur dif ferently at 410-480 nm and 500-560 nm for PSP and non-PSP microalgae,respectively.The identification accuracies of ML models(support vector machine(SVM),and k-nearest neighbor rule(k-NN)),and DL model(convolutional neural network(CNN))to PSP microalgae are 96.25%,96.36%,and 95.88%respectively,indicating that ML and DL are suitable for the classifi cation of toxic microalgae.
基金This work was supported by National Natural Science Foundation of China under grant No.81071221.
文摘We used resting-state functional magnetic resonance imaging(fMRI)to determine whether there are any abnormalities in different frequency bands between amplitude of low-frequency fluctuations(ALFF)and fractional ALFF(fALFF)and between 10 early amnestic mild cognitive impairment(EMCI)patients and eight normal controls participating in the Alzheimer’s Disease Neuroimaging Initiative(ADNI).We showed widespread difference in ALFF/fALFF between two frequency bands(slow-4:0.027-0.073 Hz,slow-5:0.01-0.027 Hz)in many brain areas including posterior cingulate cortex(PCC),medial prefrontal cortex(MPFC),suprasellar cistern(SC)and ambient cistern(AC).Compared to the normal controls,the EMCI patients showed increased ALFF values in PCu,cerebellum,occipital lobe and cerebellum posterior lobe in frequency band slow-4.While in frequency band slow-5,the EMCI patients showed decreased ALFF values in temporal lobe,left cerebrum and middle temporal gyrus5.Moreover,the EMCI patients showed increased fALFF values in frontal lobe and inferior frontal gyrus in band slow-5.While in frequency band slow-4,the EMCI patients showed decreased fALFF values in limbic lobe,cingulate gyrus and corpus callosum.These results demonstrated that EMCI patients had widespread abnormalities of amplitude of LFF in different frequency bands.
基金National Natural Science Foundation of China(Nos.22131008 and 21971127)the Haihe Laboratory of Sustainable Chemical Transformations for financial support.
文摘Implantable system maximizes drug concentration and continuously releases drugs near the tumor,which is an effective tool to solve the difficult retention of chemotherapy drugs in bladder cancer.In this work,a novel polysaccharide supramolecular injectable hydrogel(CCA hydrogels for short)is rapidly constructed by simply mixing cationic chitosan,anionic sulfobutyl etherβ-cyclodextrin(SBE-β-CD)and a trace amount of silver ions.The injected hydrogel reconstituted and regained its shape in less than 1 h,and it can still maintain the elasticity suitable for the human body.By packaging the drug directly,the gel achieves a high concentration of doxorubicin,an anticancer drug.Using MB49-luc cells as the model of bladder tumor for anti-tumor in vivo,the CCA-DOX gel has obvious inhibitory effect on bladder tumor,and its inhibitory effect is much greater than that of free DOX.Therefore,this self-healing injectable hydrogel has great potential for in situ treatment of bladder cancer.
基金National Natural Science Foundation of China(Nos.22131008 and 21971127)the Fundamental Research Funds for the Central Universitiesthe Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘In recent years,multicolor cascade supramolecular assemblies with controllable topological morphology have become a research hotspot due to their wide application in light-emitting materials,cell imaging and other fields.Herein,several kinds of macrocycles including cucurbiturils,calixarene and cyclodextrins are used as building blocks to construct fluorescent assemblies with anthryl-conjugated phenylpyridine(G),wherein cucurbit[8]uril(CB[8])and G can form nanowires at a stoichiometric ratio of n:n through host-guest encapsulation to form a non-covalent heterodimer.Significantly,the macrocycle confinement effect drastically enhances the fluorescence emission of G and emission peak generated bathochromic shift from 500 nm to 600 nm.When the supramolecular polymer is further assembled with amphiphilic calix[4]arene(SC_(4)A8),the fluorescence emission of G?CB[8]further increases to 1.4 times,accompanied by the morphological transformation from linear structure to nanorod structure.Subsequently,a very small amount of dye Cy5 is added to the assembly solution as an energy receptor,and the negatively charged G?CB[8]@SC_(4)A8 system is regarded as an energy donor.The efficient energy transfer process enables near-infrared(NIR)emission at 675 nm with 71%energy transfer efficiency(ΦET)at a donor/receptor ratio of 100:1.Finally,the cascade supramolecular assembly has been successfully applied to targeted imaging in the nucleus of HeLa and A549 cancer cells.
基金supported by the National Natural Science Foundation of China (Nos. 50725828, 50908046, and 50978056)the Teaching & Scientific Research Fund for Excellent Young Teachers of Southeast University+2 种基金the Open Fund of Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Engineeringthe Basic Scientific & Research Fund of Southeast University (No. Seucx-201106)the Priority Academic Program Development Foundation of Jiangsu Higher Education Institutions, China
文摘Time domain analysis is an essential implement to study the buffeting behavior of long-span bridges for it can consider the non-linear effect which is significant in long-span bridges. The prerequisite of time domain analysis is the accurate description of 3D turbulence winds. In this paper, some hypotheses for simplifying the 3D turbulence simulation of long-span cable-stayed bridges are conducted, considering the structural characteristics. The turbulence wind which is a 3D multivariate stochastic vector process is converted into four independent 1D univariate stochastic processes. Based on recorded wind data from structural health monitoring system (SHMS) of the Sutong Bridge, China, the measured spectra expressions are then presented using the nonlinear least-squares fitting method. Turbulence winds at the Sutong Bridge site are simulated based on the spectral representation method and the Fast Fourier transform (FFT) technique, and the relevant results derived from target spectra including measured spectra and recommended spectra are compared. The reliability and accuracy of the presented turbulence simulation method are validated through comparisons between simulated and target spectra (measured and recommended spectra). The obtained turbulence si-mulations can not only serve further analysis of the buffeting behavior of the Sutong Bridge, but references for structural anti-wind design in adjacent regions.
基金supported by the National Natural Science Foundation of China(No.51178101,51378112)National Scientific and Technological Supporting Plan(No.2011BAK02B03)Scientific Research and Development Foundation of Fujian University of Technology(No.GY-Z10085)
文摘In the engineering practice, merging statistical analysis into structural evaluation and assessment is a tendency in the future. As a combination of mathematical and statistical techniques, response surface (RS) methodology has been successfully applied to design optimization, response prediction and model validation. With the aid of RS methodology, these two serial papers present a finite element (FE) model updating and validation method for bridge structures based on structural health monitoring. The key issues to implement such a model updating are discussed in this paper, such as design of experiment, parameter screening, construction of high-order polynomial response surface model, optimization methods and precision inspection of RS model. The proposed procedure is illustrated by a prestressed concrete continuous rigid-frame bridge monitored under operational conditions. The results from the updated FE model have been compared with those obtained from online health monitoring system. The real application to a full-size bridge has demonstrated that the FE model updating process is efficient and convenient. The updated FE model can relatively reflect the actual condition of Xiabaishi Bridge in the design space of parameters and can be further applied to FE model validation and damage identification.
基金supported by the National Natural Science Foundation of China(No.51178101,51378112)National Scientific and Technological Supporting Plan(No.2011BAK02B03)Scientific Research and Development Foundation of Fujian University of Technology(No.GY-Z10085)
文摘Because of uncertainties involved in modeling, construction, and measurement systems, the assessment of the FE model validation must be conducted based on stochastic mea- surements to provide designers with confidence for further applications. In this study, based on the updated model using response surface methodology, a practical model vali- dation methodology via uncertainty propagation is presented. Several criteria of testing/ analysis correlation are introduced, and the sources of model and testing uncertainties are also discussed. After that, Monte Carlo stochastic finite element (FE) method is employed to perform the uncertainty quantification and propagation. The proposed methodology is illustrated with the examination of the validity of a large-span prestressed concrete continuous rigid frame bridge monitored under operational conditions. It can be concluded that the calculated frequencies and vibration modes of the updated FE model of Xiabaishi Bridge are consistent with the measured ones. The relative errors of each frequency are all less than 3.7%. Meanwhile, the overlap ratio indexes of each frequency are all more than 75%; The MAC values of each calculated vibration frequency are all more than 90%. The model of Xiabaishi Bridge is valid in the whole operation space including experimental design space, and its confidence level is upper than 95%. The validated FE model of Xia- baishi Bridge can reflect the current condition of Xiabaishi Bridge, and also can be used as basis of bridge health monitoring, damage identification and safety assessment.