A highly sensitive fluorescence quenching method for the determination of chromium(VI)based on the system of Cr(VI)OFluorophenylfluorone(OFPF)cetyltrimethylammonium bromide(CTMAB)sodium tartrate(Tartrate)was developed...A highly sensitive fluorescence quenching method for the determination of chromium(VI)based on the system of Cr(VI)OFluorophenylfluorone(OFPF)cetyltrimethylammonium bromide(CTMAB)sodium tartrate(Tartrate)was developed.In a pH 420～480 medium of HAcNaAc,chromium(VI)reacts with OFPF,CTMAB and Tartrate to form a nonfluorescent mixed complex and quenches the fluorescence intensity of OFPF.There is a linear relationship between fluorescence quenching intensity and concentration of chromium(VI)from 0 to 02μg/25ml.The detection limit for Cr(VI)is 01μg/L.The method has been applied to the determination of trace chromium(VI)in water samples with satisfactory results.展开更多
Oxidative stress causes damage to cells and brain injury-associated disorders.The study aimed to investigate how the tripeptide Phe-Pro-Phe(FPF),derived from an antioxidant-rich Antarctic krill peptide Ser-Ser-Asp-Ala...Oxidative stress causes damage to cells and brain injury-associated disorders.The study aimed to investigate how the tripeptide Phe-Pro-Phe(FPF),derived from an antioxidant-rich Antarctic krill peptide Ser-Ser-Asp-Ala-Phe-Phe-Pro-Phe-Arg(SSDAFFPFR),could protect against oxidative stress caused by scopolamine.Utilizing mouse and cell models to induce oxidative stress injury with scopolamine,coupled with Fourier transform infrared(FTIR)microscopy,immunofluorescence,and mitochondrial function assays,the study demonstrated that FPF significantly reduced malondialdehyde(MDA)and reactive oxygen species(ROS)levels,as well as decreasing the expression level of the apoptotic protein Caspase-3,while also increasing superoxide dismutase(SOD)activity and unsaturated lipid levels.Furthermore,FPF significantly improved mitochondrial aerobic respiration oxygen consumption rate(OCR)and anaerobic glycolytic metabolism extracellular acidification rate(ECAR)in mouse hippocampal neuron(HT22)cells.The results indicated that FPF protected against scopolamine-induced oxidative stress by regulating anti-oxidative activity,enhancing Caspase-3 expression,increasing unsaturated lipid levels,and improving cellular energy metabolism.展开更多
Researches show that multilayer optical thin film stack can exhibit superprism effect due to their large abnormal dispersions. We investigated and simulated this effect numerically in a 1-D non-periodic film structure...Researches show that multilayer optical thin film stack can exhibit superprism effect due to their large abnormal dispersions. We investigated and simulated this effect numerically in a 1-D non-periodic film structure-Fabry-Perot filters (FPF), which possess drastic change in phase and large group delay around wavelength of peak transmittance, and fabricated this device to realize remarkable superprism effect. We tested experimentally with the maximum spatial separation shift up to 65 μm, and the experimental result is in good agreement with the theory. Compared with the traditional prism, the total thickness of our structure is only 3.3 μm, and our prism shows a stronger angular resolution of 1.8°/nm.展开更多
文摘A highly sensitive fluorescence quenching method for the determination of chromium(VI)based on the system of Cr(VI)OFluorophenylfluorone(OFPF)cetyltrimethylammonium bromide(CTMAB)sodium tartrate(Tartrate)was developed.In a pH 420～480 medium of HAcNaAc,chromium(VI)reacts with OFPF,CTMAB and Tartrate to form a nonfluorescent mixed complex and quenches the fluorescence intensity of OFPF.There is a linear relationship between fluorescence quenching intensity and concentration of chromium(VI)from 0 to 02μg/25ml.The detection limit for Cr(VI)is 01μg/L.The method has been applied to the determination of trace chromium(VI)in water samples with satisfactory results.
基金support provided by the National Key Research and Development Program of China(2023YFF110520202).
文摘Oxidative stress causes damage to cells and brain injury-associated disorders.The study aimed to investigate how the tripeptide Phe-Pro-Phe(FPF),derived from an antioxidant-rich Antarctic krill peptide Ser-Ser-Asp-Ala-Phe-Phe-Pro-Phe-Arg(SSDAFFPFR),could protect against oxidative stress caused by scopolamine.Utilizing mouse and cell models to induce oxidative stress injury with scopolamine,coupled with Fourier transform infrared(FTIR)microscopy,immunofluorescence,and mitochondrial function assays,the study demonstrated that FPF significantly reduced malondialdehyde(MDA)and reactive oxygen species(ROS)levels,as well as decreasing the expression level of the apoptotic protein Caspase-3,while also increasing superoxide dismutase(SOD)activity and unsaturated lipid levels.Furthermore,FPF significantly improved mitochondrial aerobic respiration oxygen consumption rate(OCR)and anaerobic glycolytic metabolism extracellular acidification rate(ECAR)in mouse hippocampal neuron(HT22)cells.The results indicated that FPF protected against scopolamine-induced oxidative stress by regulating anti-oxidative activity,enhancing Caspase-3 expression,increasing unsaturated lipid levels,and improving cellular energy metabolism.
文摘Researches show that multilayer optical thin film stack can exhibit superprism effect due to their large abnormal dispersions. We investigated and simulated this effect numerically in a 1-D non-periodic film structure-Fabry-Perot filters (FPF), which possess drastic change in phase and large group delay around wavelength of peak transmittance, and fabricated this device to realize remarkable superprism effect. We tested experimentally with the maximum spatial separation shift up to 65 μm, and the experimental result is in good agreement with the theory. Compared with the traditional prism, the total thickness of our structure is only 3.3 μm, and our prism shows a stronger angular resolution of 1.8°/nm.
