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The study of effect and mechanism of 630-nm laser on human lung adenocarcinoma cell xenograft model in nude mice mediated by hematoporphyrin derivatives
摘要： To investigate the effect and mechanism of 630-nm laser on human lung adenocarcinoma cell xenograft model in nude mice mediated by hematoporphyrin derivatives (HPD) and provide theoretical basis for clinical photodynamic therapy (PDT). Human lung adenocarcinoma cell xenograft model in nude mice was established and randomly divided into four groups: control group, pure photosensitizer group, pure irradiation group, and photodynamic treatment group. The tumor volume growth was compared, and the tumor growth inhibition rate was calculated. HE staining was used for routine pathological observation of tumor sections, and gross conditions of cells, interstitium, and blood vessels in several groups of tumor tissues were observed. TUNEL staining was used to observe and compare the apoptosis induced by photodynamic therapy. Real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression level of angiogenesis-related factors VEGF, HIF-1α and apoptosis-related factors Bax and Bcl-2 mRNA in the transplanted tumor tissues. Western blot was employed to detect the expression of angiogenesis-related proteins VEGF, HIF-1α and apoptosis-related proteins Bax, Caspase-3, and Bcl-2. Compared with the other three groups, the tumor growth inhibition rate of the photodynamic treatment group was significantly increased and the difference was statistically significant (P < 0.05). HE staining showed that the animal model of lung adenocarcinoma A549 was successfully established. TUNEL staining revealed that more apoptotic cells were found in the photodynamic treatment group, and the apoptosis index was calculated. Compared with the other three groups, the difference was statistically significant (P < 0.05). RT-PCR results showed that compared with the other three groups, the mRNA expressions of VEGF, HIF-1α, and Bcl-2 in the photodynamic treatment group decreased, while the expression of Bax mRNA increased(P < 0.05), and the differences were statistically significant. Western blot results showed that protein expressions of VEGF, HIF-1α, and Bcl-2 decreased in the photodynamic treatment group, while protein expression level of Bax and Caspase-3 increased (P < 0.05), indicating statistically significant differences. The 630-nm laser mediated by hematoporphyrin derivatives can significantly inhibit the growth of human lung adenocarcinoma xenograft tumor in nude mice, the mechanism of which is related to the inhibition of tumor angiogenesis by down-regulating VEGF and HIF-1α gene expression, and the promotion of tumor apoptosis by up-regulating Bax, Caspase-3, and down-regulating Bcl-2 gene expression.
关键词： Angiogenesis,Animal models,Lung adenocarcinoma,Photodynamic therapy,Apoptosis
更新于2025-09-19 17:13:59
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[IEEE 2019 International Conference on Computer, Electrical & Communication Engineering (ICCECE) - Kolkata, India (2019.1.18-2019.1.19)] 2019 International Conference on Computer, Electrical & Communication Engineering (ICCECE) - Development of Current Sensorless Photovoltaic MPP Tracker
摘要： Recent advances in energy storage devices (ESDs) technology have enabled new guidance strategies for power generation and distribution on hybrid marine power plants, supported by new class regulations. In this paper, a new model to calculate the fuel saving and emission reduction potential is derived based on the ESD maximum charge/discharge rate, engine efficiency, and specific fuel oil consumption (SFOC) curve. Several cases were analyzed with generator disconnection and also without it. Spline approximation for the discrete fuel oil consumption curve is used for numerical solution and later optimized using the Karush–Kuhn–Tucker method. A second approach is proposed, using linear interpolation, reducing the optimization process computational time. It is shown that fuel savings can be increased and emissions reduced by charging and discharging the energy storage device. This is denoted as strategic loading according to the proposed model. The cases with highest potential for fuel saving are shown to be cases where generators are disconnected.
关键词： energy storage,analytical models,Hybrid power systems,smart grids,optimization,fuel economy,numerical models
更新于2025-09-16 10:30:52
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Frontiers in Evolutionary Economics (Themenheft 2+3/Bd. 234(2014) Jahrbücher für National?konomie und Statistik) || Like Doktorvater, like Son? Tracing Role Model Learning in the Evolution of German Laser Research
摘要： We trace individual-level learning and knowledge transfer in public research by matching about 5,000 doctoral dissertations and their advisors over the full history of German laser research. We study the number of laser-related dissertations per advisor, publication and patent outputs of advisors and doctoral students, as well as the likelihood that former students started laser firms or attained professorships. Our results suggest a substantial relevance of non-codified knowledge and role model learning in public research. There is little evidence of pronounced barriers to entry into laser research.
关键词： role models,observational learning,doctoral dissertations,Open science,laser research
更新于2025-09-16 10:30:52
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Simulated photo-degradation of dissolved organic matter in lakes revealed by three-dimensional excitation-emission matrix with regional integration and parallel factor analysis
摘要： Simulated photo-degradation of fluorescent dissolved organic matter (FDOM) in Lake Baihua (BH) and Lake Hongfeng (HF) was investigated with three-dimensional excitation-emission matrix (3DEEM) fluorescence combined with the fluorescence regional integration (FRI), parallel factor (PARAFAC) analysis, and multi-order kinetic models. In the FRI analysis, fulvic-like and humic-like materials were the main constituents for both BH-FDOM and HF-FDOM. Four individual components were identified by use of PARAFAC analysis as humic-like components (C1), fulvic-like components (C2), protein-like components (C3) and unidentied components (C4). The maximum 3DEEM fluorescence intensity of PARAFAC components C1eC3 decreased by about 60%, 70% and 90%, respectively after photo-degradation. The multi-order kinetic model was acceptable to represent the photo-degradation of FDOM with correlation coefficient (Radj2) (0.963e0.998). The photo-degradation rate constants (kn) showed differences of three orders of magnitude, from 1.09(cid:1) 10(cid:3)6 to 4.02 (cid:1) 10(cid:3)4 min(cid:3)1, and half-life of multi-order model (Tn1=2) ranged from 5.26 to 64.01 min. The decreased values of fluorescence index (FI) and biogenic index (BI), the fact that of percent fluorescence response parameter of Region I (PI,n) showed the greatest change ratio, followed by percent fluorescence response parameter of Region II (PII,n), while the largest decrease ratio was found for C3 components, and the lowest Tn1=2 was observed for C3, indicated preferential degradation of protein-like materials/components derived from biological sources during photo-degradation. This research on the degradation of FDOM by 3DEEM/FRI-PARAFAC would be beneficial to understanding the photo-degradation of FDOM in natural environments and accurately predicting the environmental behaviors of contaminants in the presence of FDOM.
关键词： Fluorescence regional integration,Parallel factor analysis,Photo-degradation,Fluorescent dissolved organic matter,Multi-order kinetic models,Three-dimensional excitation-emission matrix
更新于2025-09-16 10:30:52
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Relativistic Evaluation Models of Laser Time Transfer between Satellites Resulting from Orbit Perturbations and Attitude Jitters
摘要： The realization of picosecond level laser time transfer between satellites plays a key role in microgravity scientific missions, such as gravitational wave detection, next generation GNSS (Global Navigation Satellite System), deep space exploration, testing general relativity and searching for dark matter. In picosecond or higher level, a deep insight of relativistic error of laser time transfer between satellites induced by orbit perturbations and attitude jitters is urgently needed, which contributes to the compensation of relativistic error. Firstly, this paper points out the problem of orbit perturbations and attitude jitters. Then, the relativistic evaluation models of one-way laser time transfer and two-way laser time transfer resulting from orbit perturbations and attitude jitters are investigated. The relativistic evaluation models are proposed with incorporation of attitude dynamics and orbit dynamics of satellites, as well as relativistic models of one-way laser time transfer and two-way laser time transfer. Simulation studies are carried out to analyze the effect of orbit perturbations and attitude jitters on the relativistic error. Simulation results show that the relativistic error induced by orbit perturbations increases with time and the relativistic error induced by attitude jitters displays periodic variation. Furthermore, the relativistic error of two-way laser time transfer is less than one-way laser time transfer.
关键词： Laser time transfer,Relativistic evaluation models,Gravitational wave detection,Orbit perturbations,Attitude jitters
更新于2025-09-16 10:30:52
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Predictive Modeling Of Laser Assisted Hybrid Machining Parameters Of Inconel 718 Alloy Using Statistical And Artificial Neural Network
摘要： Laser assisted hybrid machining being researched in past decade on various difficult to machine materials to improve the machinability. Predictive modeling approaches such as response surface method (RSM) and artificial neural network (ANN) are widely applied for model development. However, no reported work using RSM and ANN approaches to predict the relationship between the experimental variables (speed, feed, laser power and beam apporach angle) on surface roughness Ra (μm). Furthermore, coefficient of correlation (R2), root mean square error (RMSE) and model predictive error (MPE) are considered as a performance measures for their effectiveness. The results show that the ANN model estimates the machinability indices with high accuracy with a limited number of experiments compared to the response surface model. From the comparative study, ANN model is found to be capable for better prediction of response than the RSM model. ANN model provides a maximum precision benefit of 10% for surface roughness Ra (μm) compared with RSM model. Also the calculated Pearson correlation coefficient showed a robust relationship between the laser beam angle and Ra, surface roughness followed by the speed.
关键词： response surface methodology,surface roughness,neural network,empirical models
更新于2025-09-16 10:30:52
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Practical aspects of landslides surveys using terrestrial laser scanning in diverse geomorphological terrains: case studies from Polish Carpathians and Lower Vistula Valley
摘要： High-resolution digital elevation models from terrestrial laser scanning (TLS) in recent years have been more and more often used at various stages of landslide surveys. The article presents examples of TLS use in landslide research in areas that differ in morphogenesis: in mountains and in a lowland river valley. The examples concern the monitoring of mass movements from short and long distances (up to 3100 m), generation of differential models, and estimation of surface deformation. We also discussed the limitations of TLS measurements.
关键词： long-range terrestrial laser scanner,landslide monitoring,high-resolution digital elevation models,landslide surveys
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Metrological assessment of the indirect method of measuring the concentration of oxygen in the air
摘要： Greenhouse Gases Observing Satellite (GOSAT), which measures column-averaged carbon dioxide dry air mole fractions (Xco2) from space, provides new data sources to improve our understanding of carbon cycle. The available GOSAT data, however, have many gaps and are irregularly positioned, which make it difficult to directly interpret their scientific significance without further data analysis. Spatio-temporal geostatistical prediction approach can be used to fill the gaps for global and regional Xco2 mapping. It is important to choose a suitable spatio-temporal variogram model since modeling spatio-temporal correlation structure using variogram model is a critical step in the geostatistical prediction. In this study, three different flexible spatio-temporal variogram models, including the product-sum model, Cressie–Huang model, and Gneiting model, are used to model the spatio-temporal correlation structure of Xco2 over China, using the Atmospheric CO2 Observations from Space retrievals of the GOSAT (ACOS-GOSAT) Xco2 (v3.3) data products. The three models are compared and evaluated using the weighted mean square errors (WMSE) indicating the fitness between the empirical variogram surface and the theoretical variogram model, cross-validation for quantifying prediction accuracies, and the performance of the three models when used to fill the spatial gaps and generate Xco2 maps in 3-day temporal interval. The results indicate that 1) the model fitness of the commonly used product-sum model is slightly better than Cressie–Huang model and Gneiting model as indicated from WMSE, and 2) all the three models present similar summary statistics in cross-validation, all with a significantly high correlation coefficient of 0.92, and about 83% of prediction error within 2 ppm and about 53% within 1 ppm, and (3) differences between the mapping results using the three models are generally less than 0.1 ppm, and no significant differences can be identified. As a conclusion from the above results, all the three variogram models can precisely catch the empirical characteristics of the spatio-temporal correlation structure of Xco2 over China, and the precision and effectiveness of predicting and mapping Xco2 using the three models are almost the same.
关键词： spatio-temporal kriging,spatio-temporal variogram models,carbon dioxide,mapping,ACOS-GOSAT
更新于2025-09-16 10:30:52
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[IEEE 2018 International Conference Laser Optics (ICLO) - St. Petersburg (2018.6.4-2018.6.8)] 2018 International Conference Laser Optics (ICLO) - Optical stabilization and microscanning with piezo actuators and piezoelectric motors
摘要： Building models are a valuable information source for urban studies and in particular for analyses of urban mass concentrations (UMCS). Most commonly, light detection and ranging (LiDAR) is used for their generation. The trade-off for the high geometric detail of these data is the low spatial coverage, comparably high costs and low actualization rates. Spaceborne stereo data from Cartosat-1 are able to cover large areas on the one hand, but hold a lower geometric resolution on the other hand. In this paper, we investigate to which extent the geometric shortcomings of Cartosat-1 can be overcome integrating building footprints from topographic maps for the derivation of large-area building models. Therefore, we describe the methodology to derive digital surface models (DSMs) from Cartosat-1 data and the derivation of building footprints from topographic maps at 1:25 000 (DTK-25). Both data are fused to generate building block models for four metropolitan regions in Germany with an area of ～ 16 000 km2. Building block models are further aggregated to 1 × 1 km grid cells and volume densities are computed. Volume densities are classi?ed to various levels of UMCs. Performance evaluation of the building block models reveals that the building footprints are larger in the DTK-25, and building heights are lower with a mean absolute error of 3.21 m. Both factors in?uence the building volume, which is linearly lower than the reference. However, this error does not affect the classi?cation of UMC, which can be classi?ed with accuracies between 77% and 97%.
关键词： topographic maps,Building model,digital elevation models,cartosat
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 28th International Symposium on Industrial Electronics (ISIE) - Vancouver, BC, Canada (2019.6.12-2019.6.14)] 2019 IEEE 28th International Symposium on Industrial Electronics (ISIE) - A study on the lifetime estimation of photovoltaic modules under accelerated environmental conditions
摘要： Lifetime estimation is critical for predicting the revenue of the photovoltaic (PV) plant to be built. Therefore it must be done before huge investments will be made to build and operate a PV plant. Since the degradation rate of PV modules features as a random variable, statistical models are commonly used to estimate the lifetime of PV modules. However, most existing researches select the statistical model to describe the degradation rate of PV modules empirically, and lack of basis. In this paper we propose a practical procedure for selecting the statistical model which describes the degradation rate of PV modules best. Based on the selected model, the lifetime of PV modules is estimated. We use probability plots and hypothesis tests to validate the distributional assumptions. Then we use negative log-likelihood values to further determine the distribution that describes the lifetimes best. Three classical distributions, i.e., Weibull, lognormal and exponential distributions, are considered. The life distributions at different stress levels are assumed to come from the same parametric family. Based on the assumption, the parameters of the hypothesized distributions are estimated using maximum likelihood estimation methods. It is found that the PV lifetimes follow a parametric location-scale distribution family, and they follow the Weibull distribution best. The conclusion is realistic from a physical point of view.
关键词： accelerated tests,photovoltaic modules,statistical models,distribution determination,lifetime estimation
更新于2025-09-16 10:30:52