27 research outputs found
Poly (lactic-co-glycolic acid)-encapsulated iodine-131 nanoparticles fabricated with rhTSH induce apoptosis and immobilization of thyroid cancer cells
BackgroundAggressive thyroid carcinoma (ATC) usually loses radioiodine avidity to iodine-131 (131I) due to the downregulation of sodium/iodide symporter (NIS). The expression of thyroid stimulating hormone receptor (TSHR) is more persistent than NIS and the administration of recombinant human thyroid stimulating hormone (rhTSH) promotes de novo NIS synthesis. Hence, exploring methods integrating 131I with rhTSH might be a feasible therapeutic strategy for selective delivery of 131I into thyroid cancer to fortify the effect of radioiodine ablation.MethodsThe 131I, poly (lactic-co-glycolic acid) (PLGA) and rhTSH were used to synthesize of the 131I-PLGA-rhTSH nanoparticles. The characteristics of the 131I-PLGA-rhTSH nanoparticles was determined using a light microscopy, scanning electron microscopy (SEM), autoradiography and immunofluorescence (IF) staining. The diameter of the 131I-PLGA-rhTSH nanoparticles was measured with a Mastersizer 3000, and the encapsulation efficiency (EF) of 131I in 131I-PLGA-rhTSH nanoparticles and the radioactivity of a single nanoparticle were determined. Then, the mouse tumor xenograft model was established, and the biodistribution and effect of 131I-PLGA-rhTSH nanoparticles on apoptosis of thyroid cance cells were investigated in vivo. Thereafter, the role of 131I-PLGA-rhTSH nanoparticles in cell viability using cell counting kit-8 and lactate dehydrogenase (LDH) release assays. Subsequently, the underlying mechanism of 131I-PLGA-rhTSH nanoparticles in reducing cell viability was assessed using immunostaining, boyden invasion assays and phalloidin staining.ResultsOur results showed that the method of developing nanoparticles-encapsulated 131I using poly (lactic-co-glycolic acid) (PLGA) and modified with rhTSH (131I-PLGA-rhTSH), was a feasible avenue for the integration of 131I and rhTSH. Meanwhile, the encapsulation efficiency (EF) of 131I-PLGA-rhTSH nanoparticles was approximately 60%, and the radioactivity of a single nanoparticle was about 1.1Ă—10-2 Bq. Meanwhile, the 131I-PLGA-rhTSH nanoparticles were selectively delivered into, gradually enriched and slowly downregulated in xenograft tumor after the administration of 131I-PLGA-rhTSH nanoparticles through tail vein in mouse tumor xenograft model. Thereafter, the tumor weight was significantly reduced after the administration of 131I-PLGA-rhTSH nanoparticles. Subsequently, the application of 131I-PLGA-rhTSH nanoparticles facilitated apoptosis and attenuated immobilization via inhibiting F-actin assembling of FTC-133 cells.ConclusionThe present study develops a suitable approach integrating 131I and rhTSH, and this strategy is a feasible regimen enhancing the effect of radioiodine ablation for the treatment of thyroid cancer
Parameterization of Wave-Induced Mixing Using the Large Eddy Simulation (LES) (I)
Turbulent motions in the thin ocean surface boundary layer control exchanges of momentum, heat and trace gases between the atmosphere and ocean. However, present parametric equations of turbulent motions that are applied to global climate models result in systematic or substantial errors in the ocean surface boundary layer. Significant mixing caused by surface wave processes is missed in most parametric equations. A Large Eddy Simulation model is applied to investigate the wave-induced mixed layer structure. In the wave-averaged equations, wave effects are calculated as Stokes forces and breaking waves. To examine the effects of wave parameters on mixing, a series of wave conditions with varying wavelengths and heights are used to drive the model, resulting in a variety of Langmuir turbulence and wave breaking outcomes. These experiments suggest that wave-induced mixing is more sensitive to wave heights than to the wavelength. A series of numerical experiments with different wind intensities-induced Stokes drifts are also conducted to investigate wave-induced mixing. As the wind speed increases, the influence depth of Langmuir circulation deepens. Additionally, it is observed that breaking waves could destroy Langmuir cells mainly at the sea surface, rather than at deeper layers
An Improved Approach to Wave Energy Resource Characterization for Sea States with Multiple Wave Systems
Generally, wave energy resource assessment and characterization are performed based on an entire wave spectrum, ignoring the detailed energy features that belong to wave systems, i.e., wind waves and swells. In reality, the energy is separately possessed by multiple wave systems, propagating at different directions and velocities. Therefore, it is the wave system that is the most fundamental unit of the wave energy resource. Although detailed analyses of wind waves and swells can be conducted via wave system partitioning, operational assessment methods that can reveal the detailed wave energy characteristics of wave systems still deserve further development. Following a two-step partitioning procedure, this paper presents an improved approach to the characterization of wave energy resources based on grouped wave systems. Wave systems classified as the same group are consistent in terms of propagation direction, velocity, and other characteristics of wave energy, but these characteristics between the groups are obviously different. Therefore, in comparison with the traditional method, the new approach can reveal more comprehensive and more detailed characteristics of the wave energy resource in terms of (i) wind-sea and swell components, (ii) directionality, and (iii) wave conditions; details that represent valuable information for the improvement of the performance of wave energy converter devices and the optimization of the layout of device arrays in wave farms
Assessment of monthly economic losses in Wuhan under the lockdown against COVID-19
Abstract With the outbreak of COVID-19 in Wuhan, aggressive countermeasures have been taken, including the implementation of the unprecedented lockdown of the city, which will necessarily cause huge economic losses for the city of Wuhan. In this paper, we attempt to uncover the interactions between epidemic prevention and control measures and economic-social development by estimating the health loss and meso-economic loss from a human-oriented perspective. We implemented a compartmental model for the transmission dynamics and health burden assessment to evaluate the health losses, then estimated the direct and indirect economic losses of industries using the Input-Output model. Based on these estimates, the first monthly health losses and meso-economic losses caused by the lockdown was assessed. The overall policy effect of the lockdown policy in Wuhan was also investigated. The health loss and meso-economic losses are used to evaluate the health burden and loss of residents’ mental health, the direct economic loss of several worst-hit industries, and the indirect economic loss of all industries, respectively. Our findings reveal that the health burden caused by this pandemic is estimated to be 4.4899 billion yuan (CNY), and the loss of residents’ mental health is evaluated to be 114.545 billion yuan, the direct economic losses in transport, logistics, and warehousing, postal service, food, and beverage service industries reach 21.6094 billion yuan, and the monthly indirect economic losses of all industries are 36.39661994 billion yuan caused by the lockdown. The total monthly economic losses during the lockdown reach 177.0413 billion yuan. However, the lockdown policy has been considered to reduce COVID-19 infections by >180 thousand, which saves about 20 thousand lives, as well as nearly 30 billion yuan on medical costs. Therefore, the lockdown policy in Wuhan has obvious long-term benefits on the society and the total economic losses will be at a controllable level if effective measures are taken to combat COVID-19
Analysis of the Evolution Pattern and Driving Mechanism of Lakes in the Northern Ningxia Yellow Diversion Irrigation Area
In the northern part of the Ningxia Autonomous Region, there are rich lake resources, which are known as the “South of the Seas”. In recent years, the natural evolution of the water system and human activities have caused significant changes in the lake area. In order to fully understand the evolution of lakes in the northern Ningxia Yellow Irrigation Area, Landsat, Sentinel-2 images and ArcGIS were used to extract relevant information, and the cumulative distance level curve and Mann–Kendall trend analysis were used to analyze the trends of each driving factor in depth. The results showed that (1) the lake surface area in the northern Yellow Diversion Irrigation Area showed a significant increasing trend from 1986 to 2019. (2) The annual average temperature in the Ningxia Yellow River Irrigation Area has shown an increasing trend over the past 39 years, and no year has obvious cyclical changes, but in 1998, there was a sudden change in temperature and the temperature began to rise sharply; the annual average precipitation showed an increasing trend with a large variation, and the annual average precipitation from 1980 to 2018 showed a fluctuating increasing trend. (3) There is no significant linear pattern of runoff from upstream during 1986–2015, and it is characterized by fluctuating changes; the precipitation in the Yellow Irrigation Area is much lower than the average level in Ningxia, and it is classified as a typical arid area; the water consumption is all decreasing, but its linear trend is not significant; the most significant impact of the change in the substratum on the water surface is the construction of fields around the lake after 1990, followed by the Lake engineering treatment. (4) The water surface area of the mainstream is significantly and positively correlated with the incoming water from upstream, is significantly and negatively correlated with the area of grassland, and is significantly and positively correlated with the areas of arable land and construction land. The effect of land cover on the water surface area of the mainstream is lower than that on the water surface area other than the mainstream
Analysis of the Evolution Pattern and Driving Mechanism of Lakes in the Northern Ningxia Yellow Diversion Irrigation Area
In the northern part of the Ningxia Autonomous Region, there are rich lake resources, which are known as the “South of the Seas”. In recent years, the natural evolution of the water system and human activities have caused significant changes in the lake area. In order to fully understand the evolution of lakes in the northern Ningxia Yellow Irrigation Area, Landsat, Sentinel-2 images and ArcGIS were used to extract relevant information, and the cumulative distance level curve and Mann–Kendall trend analysis were used to analyze the trends of each driving factor in depth. The results showed that (1) the lake surface area in the northern Yellow Diversion Irrigation Area showed a significant increasing trend from 1986 to 2019. (2) The annual average temperature in the Ningxia Yellow River Irrigation Area has shown an increasing trend over the past 39 years, and no year has obvious cyclical changes, but in 1998, there was a sudden change in temperature and the temperature began to rise sharply; the annual average precipitation showed an increasing trend with a large variation, and the annual average precipitation from 1980 to 2018 showed a fluctuating increasing trend. (3) There is no significant linear pattern of runoff from upstream during 1986–2015, and it is characterized by fluctuating changes; the precipitation in the Yellow Irrigation Area is much lower than the average level in Ningxia, and it is classified as a typical arid area; the water consumption is all decreasing, but its linear trend is not significant; the most significant impact of the change in the substratum on the water surface is the construction of fields around the lake after 1990, followed by the Lake engineering treatment. (4) The water surface area of the mainstream is significantly and positively correlated with the incoming water from upstream, is significantly and negatively correlated with the area of grassland, and is significantly and positively correlated with the areas of arable land and construction land. The effect of land cover on the water surface area of the mainstream is lower than that on the water surface area other than the mainstream
Validation of an Improved Statistical Theory for Sea Surface Whitecap Coverage Using Satellite Remote Sensing Data
The whitecap coverage at the sea surface is affected by the ratio of kinetic energy to potential energy, θ, the wave spectrum width parameter, ρ, and other factors. This paper validates an improved statistical theory for surface whitecap coverage. Based on the theoretical analysis, we find that the whitecap coverage is more sensitive to ρ than to θ, and the improved statistical theory for surface whitecap coverage is suitable in regions of rough winds and waves. The satellite-derived whitecap coverage data in the westerly wind zone is used to validate the improved theory. The comparison between the results from theory and observations displays a better performance from the improved theory relative to the other methods tested
Laboratory Studies on the Rheotaxis of Fish under Different Attraction Flow Conditions
The damming of the river changes the structure of the original river ecosystem, and although fish passage plays an important role in maintaining the connectivity of the river ecosystem, the fish have difficulty finding the fish passage entrance during the upstream process. This paper studied the rheotaxis of fish under three different water flow conditions experimentally through recirculating water tanks. To better understand the response of Crucian carp (Carassius auratus) to water flow stimulation, the representative swimming trajectory, sensing success rate, attraction success rate, reaction time, and attraction time of the fish were analyzed by using a video monitoring system. The experimental results showed that fish responded differently to single-peak and lateral bimodal outflow conditions: (1) the single-peak outflow condition had a much better attraction effect than the lateral bimodal outflow condition, both in terms of sensing success rate and attraction success rate; (2) the fish swam mainly in the middle area of the lateral bimodal outflow condition, while the fish swam more evenly in the single-peak outflow condition. Therefore, setting the attraction current at the right time and near the entrance of the fish passage may help to improve the effect of fish attraction