The development of a simple and accurate quantitative method for the determination of 6-mercaptopurine (6-MP) is of great importance because of its serious side effects. Ratiometric fluorescence (RF) sensors are not s...The development of a simple and accurate quantitative method for the determination of 6-mercaptopurine (6-MP) is of great importance because of its serious side effects. Ratiometric fluorescence (RF) sensors are not subject to interference from environmental factors, and exhibit enhanced precision and accuracy. Therefore, a novel RF sensor for the selective detection of 6-MP was developed. The present work reports a sensitive and selective RF sensor for the detection of 6-mercaptopurine, by hybridizing carbon nanodots (CDots) and gold nanoclusters (AuNCs) capped with bovine serum albumin (BSA). The CDots serve as the reference signal and the AuNCs as the reporter. On addition of the 6-MP, AuNCs formed aggregates, because the existing cross-links within the AuNCs and BSA structure were broken in favour of the Au-S bonds, which can enhance the fluorescence of AuNCs, while the fluorescence of CDots is stable against 6-MP, leading to distinct ratiometric fluorescence changes when exposed to 6-MP. 6-MP could be detected in the range of 0 - 30.22 μM with a detection limit of 54 nM. The developed sensor was applied for the determination of 6-MP in human serum samples and satisfactory results were obtained.展开更多
In order to improve the concentration of selenium in the maifanite concentrate, the optimum experimental conditions were obtained by orthogonal experimentas follows: size of maifanite was 10 mesh, concentration of mai...In order to improve the concentration of selenium in the maifanite concentrate, the optimum experimental conditions were obtained by orthogonal experimentas follows: size of maifanite was 10 mesh, concentration of maifanite was 15 (expressed as the quality of maifanite divided by that of water), soaking time was 60 min at room temperature, heating temperature was 70oC, heating time was 20 min, pH value was 6. Under this condition, the concentrations of each element (ppm)determined by ICP-AES were: Fe 0.099, Cu 0.035, Mn 0.051, Zn 0.019, Se 0.028, Al 0.000.a ven in this document.展开更多
In this paper, the author reported the effect of maifanite on the learning and memory of rats suffering Cd poisoning by step-down and step-through test, analyzed the content of MDA, MT, SOD, and GSH-Px in the hippocam...In this paper, the author reported the effect of maifanite on the learning and memory of rats suffering Cd poisoning by step-down and step-through test, analyzed the content of MDA, MT, SOD, and GSH-Px in the hippocampus of rats respectively, and assayed the content of Fe, Cu, Zn, Mn, Se, and Cd in the hippocampus of rats. In the step-down test, it is found that maifanite can reduce the number of electric shock, prolong step-down latency, and cut down error times when rats are exposed to Cd 24 h. In the step-through test, maifanite can obviously prolong the latency of entering the dark cabin of rats suffering Cd poisoning. The exogenous Cd can lead to the decrease of SOD and GSH-Px activity and the increase of MDA and MT content. The alternation of maifanite and Cd by the gavage can significantly increase the SOD and GSH-Px activity as well as MT content, while lessening the MDA content. The accumulation of exogenous Cd in hippocampus causes the increase of Zn, Fe, Mn, and Cd content, and the decrease of Cu and Se content. The intake of maifanite can regulate the imbalance of metals content and make its content near to the of level control group. The research shows that maifanite can improve the ability of learning and memory of rats suffering Cd poisoning, increase MT formation and lower hyperoxidative damage. Maifanite has the function of balancing the content of trace elements in rats suffering Cd poisoning, and meanwhile can alleviate the toxicity of Cd effectively.展开更多
The linear velocity at the tip of large wind turbine blades can reach 100 m/s,generating static electricity through friction with airborne particles.However,the accumulation characteristics of precipitation static on ...The linear velocity at the tip of large wind turbine blades can reach 100 m/s,generating static electricity through friction with airborne particles.However,the accumulation characteristics of precipitation static on the blade surface and its impact on the lightning attachment characteristics are rarely reported.The authors constructed a platform for measuring charges on rotating wind turbine blades and employed the electrostatic probe method to obtain the accumulation characteristics of surface charges under different environmental conditions.The experimental results show that positive charges accumu-late on the blade surfaces,peaking at 0.69μC/m2 under experimental conditions.The charge density is positively correlated with airborne particle concentration and blade rotation speed,while it is negatively correlated with relative air humidity.Additionally,the authors developed a model of the electric field distribution on wind turbine blades considering the effects of precipitation static.Simulation results indicate that the elec-trostatic field induced by precipitation static weakens the field strength in the vicinity of receptors,reaching a minimum of only 38%of the original strength,thereby increasing the probability of lightning protection failure.The findings provide an effective supple-ment to the lightning attachment mechanism of rotating wind turbine blades.展开更多
Sensitive and rapid imaging of intracellular cancer-related miRNA holds great potential for early diagnosis and treatment monitoring of cancer.However,most imaging probes are constructed on nanoparticles that rely on ...Sensitive and rapid imaging of intracellular cancer-related miRNA holds great potential for early diagnosis and treatment monitoring of cancer.However,most imaging probes are constructed on nanoparticles that rely on passive diffusion to interact and bind with the target substance,resulting a long response time and a low target recognition capability due to the solution viscous resistance.Herein,we reported a DNA tetrahedral-modified magnetic nanorobotic probe(MNP)that performed framework nucleic acid-located catalytic hairpin assembly(CHA)reaction on the surface of magnetically driven nanorobot.The tetrahedral structure not only endowed the MNP with extremely high structural stability and perfect cell-uptake performance,but its spatial confinement effect made the signal amplification of the hairpin cascade more rapid and efficient.Additionally,the active movement of MNPs enhanced the micro-mixing of fluids and accelerated target capture,significantly reducing reaction time and improving reaction kinetics.This strategy exhibited the enhanced fluorescence signal and can accurately distinguish between miR-21 and various other miRNA sequences.Moreover,the feasibility and versatility of MNPs were also successfully verified in normal and various cancer cells imaging.Therefore,the proposed MNPs are promising candidates for the detection of intracellular biomarkers and extend the design space of self-propelled micro/nanorobots in the field of cancer diagnosis and therapy.展开更多
文摘The development of a simple and accurate quantitative method for the determination of 6-mercaptopurine (6-MP) is of great importance because of its serious side effects. Ratiometric fluorescence (RF) sensors are not subject to interference from environmental factors, and exhibit enhanced precision and accuracy. Therefore, a novel RF sensor for the selective detection of 6-MP was developed. The present work reports a sensitive and selective RF sensor for the detection of 6-mercaptopurine, by hybridizing carbon nanodots (CDots) and gold nanoclusters (AuNCs) capped with bovine serum albumin (BSA). The CDots serve as the reference signal and the AuNCs as the reporter. On addition of the 6-MP, AuNCs formed aggregates, because the existing cross-links within the AuNCs and BSA structure were broken in favour of the Au-S bonds, which can enhance the fluorescence of AuNCs, while the fluorescence of CDots is stable against 6-MP, leading to distinct ratiometric fluorescence changes when exposed to 6-MP. 6-MP could be detected in the range of 0 - 30.22 μM with a detection limit of 54 nM. The developed sensor was applied for the determination of 6-MP in human serum samples and satisfactory results were obtained.
文摘In order to improve the concentration of selenium in the maifanite concentrate, the optimum experimental conditions were obtained by orthogonal experimentas follows: size of maifanite was 10 mesh, concentration of maifanite was 15 (expressed as the quality of maifanite divided by that of water), soaking time was 60 min at room temperature, heating temperature was 70oC, heating time was 20 min, pH value was 6. Under this condition, the concentrations of each element (ppm)determined by ICP-AES were: Fe 0.099, Cu 0.035, Mn 0.051, Zn 0.019, Se 0.028, Al 0.000.a ven in this document.
文摘In this paper, the author reported the effect of maifanite on the learning and memory of rats suffering Cd poisoning by step-down and step-through test, analyzed the content of MDA, MT, SOD, and GSH-Px in the hippocampus of rats respectively, and assayed the content of Fe, Cu, Zn, Mn, Se, and Cd in the hippocampus of rats. In the step-down test, it is found that maifanite can reduce the number of electric shock, prolong step-down latency, and cut down error times when rats are exposed to Cd 24 h. In the step-through test, maifanite can obviously prolong the latency of entering the dark cabin of rats suffering Cd poisoning. The exogenous Cd can lead to the decrease of SOD and GSH-Px activity and the increase of MDA and MT content. The alternation of maifanite and Cd by the gavage can significantly increase the SOD and GSH-Px activity as well as MT content, while lessening the MDA content. The accumulation of exogenous Cd in hippocampus causes the increase of Zn, Fe, Mn, and Cd content, and the decrease of Cu and Se content. The intake of maifanite can regulate the imbalance of metals content and make its content near to the of level control group. The research shows that maifanite can improve the ability of learning and memory of rats suffering Cd poisoning, increase MT formation and lower hyperoxidative damage. Maifanite has the function of balancing the content of trace elements in rats suffering Cd poisoning, and meanwhile can alleviate the toxicity of Cd effectively.
基金General Project of National Natural Science Foundation of China,Grant/Award Number:52177015Postgraduate Scientific Research Innovation Project of Hunan Province,Grant/Award Number:CX20230843。
文摘The linear velocity at the tip of large wind turbine blades can reach 100 m/s,generating static electricity through friction with airborne particles.However,the accumulation characteristics of precipitation static on the blade surface and its impact on the lightning attachment characteristics are rarely reported.The authors constructed a platform for measuring charges on rotating wind turbine blades and employed the electrostatic probe method to obtain the accumulation characteristics of surface charges under different environmental conditions.The experimental results show that positive charges accumu-late on the blade surfaces,peaking at 0.69μC/m2 under experimental conditions.The charge density is positively correlated with airborne particle concentration and blade rotation speed,while it is negatively correlated with relative air humidity.Additionally,the authors developed a model of the electric field distribution on wind turbine blades considering the effects of precipitation static.Simulation results indicate that the elec-trostatic field induced by precipitation static weakens the field strength in the vicinity of receptors,reaching a minimum of only 38%of the original strength,thereby increasing the probability of lightning protection failure.The findings provide an effective supple-ment to the lightning attachment mechanism of rotating wind turbine blades.
基金financial support from the National Natural Science Foundation of China(Grants 62122017,82402730)National Key Research and Development Program of China(Grants 2023YFF0724300,2023YFF0724304)+1 种基金Natural Science Foundation of Chongqing,China(CSTB2023NSCQ-MSX0728)the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202300447).
文摘Sensitive and rapid imaging of intracellular cancer-related miRNA holds great potential for early diagnosis and treatment monitoring of cancer.However,most imaging probes are constructed on nanoparticles that rely on passive diffusion to interact and bind with the target substance,resulting a long response time and a low target recognition capability due to the solution viscous resistance.Herein,we reported a DNA tetrahedral-modified magnetic nanorobotic probe(MNP)that performed framework nucleic acid-located catalytic hairpin assembly(CHA)reaction on the surface of magnetically driven nanorobot.The tetrahedral structure not only endowed the MNP with extremely high structural stability and perfect cell-uptake performance,but its spatial confinement effect made the signal amplification of the hairpin cascade more rapid and efficient.Additionally,the active movement of MNPs enhanced the micro-mixing of fluids and accelerated target capture,significantly reducing reaction time and improving reaction kinetics.This strategy exhibited the enhanced fluorescence signal and can accurately distinguish between miR-21 and various other miRNA sequences.Moreover,the feasibility and versatility of MNPs were also successfully verified in normal and various cancer cells imaging.Therefore,the proposed MNPs are promising candidates for the detection of intracellular biomarkers and extend the design space of self-propelled micro/nanorobots in the field of cancer diagnosis and therapy.
