The fabrication and absolute calibration of a B-dot probe is employed to measure the pulsed magnetic field at the Shenguang-Ⅱhigh power laser facility.Copper enameled silk with a cross section diameter of 0.1 mm is u...The fabrication and absolute calibration of a B-dot probe is employed to measure the pulsed magnetic field at the Shenguang-Ⅱhigh power laser facility.Copper enameled silk with a cross section diameter of 0.1 mm is used to wind the one-turn coil with a 1 mm diameter.Two coils are paired and reversely linked to their respective circuits to form a differential B-dot probe that is sealed in and protected by a quartz shell.This B-dot probe is experimentally calibrated and then used to measure the pulsed magnetic field in laser targeting experiments at the Shenguang-Ⅱhigh power laser facility.Signals show a high performance of this B-dot probe.The common mode noise can be effectively canceled out by the differential pair.The magnetic field of over 300 T can be extrapolated at the location close to the target.展开更多
Two significant findings compel a rethink of physical theories. First, using a 7-billion-year-old gamma-ray burst, Nemiroff (2012) showed that quantum foam could not exists. And second, Solomon (2011) showed that grav...Two significant findings compel a rethink of physical theories. First, using a 7-billion-year-old gamma-ray burst, Nemiroff (2012) showed that quantum foam could not exists. And second, Solomon (2011) showed that gravitational acceleration is not associated with the gravitating mass, that gravitational acceleration g is determined solely by τ the change in time dilation over a specific height multiplied by c2 or g = τc2. Seeking consistency with Special Theory of Relativity, as means to initiate this rethink, this paper examines 12 inconsistencies in physical theories that manifest from empirical data. The purpose of this examination is to identify how gravitational theories need to change or be explored, to eliminate these 12 inconsistencies. It is then proposed that spacetime is much more sophisticated than just a 4-dimensional continuum. And, that the Universe consists of at least two layers or “kenos” (Greek for vacuous), the 4-dimensional kenos, spacetime (x, y, z, t) and the 3-dimensional kenos, subspace (x, y, z) that are joined at the space coordinates (x, y, z). This explains why electromagnetic waves are transverse, and how probabilities are implemented in Nature. This paper concludes by proposing two new instruments and one test, to facilitate research into gravitational fields, the new torsion-, tension- and stress-free near field gravity probe, the gravity wave telescope, and a non-locality test.展开更多
Rare earth elements (REEs), especially heavy rare earth elements (HREEs), are in demand for their current and emerging applications in advanced technologies. Here we perform computer-driven micro-mapping at the millim...Rare earth elements (REEs), especially heavy rare earth elements (HREEs), are in demand for their current and emerging applications in advanced technologies. Here we perform computer-driven micro-mapping at the millimeter scale of the minerals that comprise Round Top Mountain, in west Texas, USA. This large rhyolite deposit is enriched in HREEs and such other critical elements as Li, Be, and U. Electron probe microanalysis of 2 × 2 mm areas of thin sections of the rhyolite produced individual maps of 16 elements. These were superimposed to generate a 16-element composition at each pixel. Principal components analysis of elements at each pixel identified the specific mineral at that site. The pixels were then relabeled as the appropriate minerals, thereby producing a single mineral map. The overall mineral composition of the 7 studied samples compared favorably with prior analyses of the Round Top deposit available in the literature. Likewise the range of porosity in the maps was consistent with that of previous direct measurements by water saturation. This new statistical and GIS-based technique provides a robust and unbiased approach to electron microprobe mapping. The study further showed that the high-value yttrofluorite grains exhibited little tendency to cluster with other late-stage trace minerals and that the samples extended the previously documented overall homogeneity of the deposit at field scale to this microscopic scale.展开更多
Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.This investigation incorporated the difference in the‘Work ...Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.This investigation incorporated the difference in the‘Work Function'(ΔWF)measured via Kelvin Probe Force Microscopy(KPFM),as a property directly affected by interatomic bond types,i.e.the electronic structure,nanoindentation measurements,and Stacking Fault Energy values reported in the literature.It was shown that the nano-hardness of the solid-solutionα-Mg phase changed in the order of Mg-Ca>Mg-Sr>Mg-Ba.Thus,it was shown,by also considering the nano-hardness levels,that SFE of a solid-solution is closely correlated with its‘Work Function'level.Nano-hardness measurements on the eutectics andΔWF difference between eutectic phases enabled an assessment of the relative bond strength and the pertinent electronic structures of the eutectics in the three alloys.Correlation withΔWF and at least qualitative verification of those computed SFE values with some experimental measurement techniques were considered important as those computational methods are based on zero Kelvin degree,relatively simple atomic models and a number of assumptions.As asserted by this investigation,if the results of measurement techniques can be qualitatively correlated with those of the computational methods,it can be possible to evaluate the electronic structures in alloys,starting from binary systems,going to ternary and then multi-elemental systems.Our investigation has shown that such a qualitative correlation is possible.After all,the SFE values are not treated as absolute values but rather become essential in comparative investigations when assessing the influences of alloying elements at a fundamental level,that is,free electron density distributions.Our study indicated that the principles of‘electronic metallurgy'in developing multi-elemental alloy systems can be followed via practical experimental methods,i.e.ΔWF measurements using KPFM and nanoindentation.展开更多
In semiconductor manufacturing process, probe station that is testing equipment is important. Inspection step is for detecting defects on semiconductor before the packaging. Probe card is a part of probe station and c...In semiconductor manufacturing process, probe station that is testing equipment is important. Inspection step is for detecting defects on semiconductor before the packaging. Probe card is a part of probe station and contains probe tip that contacts to semiconductor. Through probe tip, it can inspect defects of semiconductor. In this paper, optimization method is used with response surface analysis to design MEMS type probe tip. And fabricating probe tip uses maskless lithography, electro-plating and lapping process.展开更多
By means of total energy calculations within the framework of the local density approximation (LDA), the interactions between a silicon Si(001) surface and a scanning probe are investigated. The tip of the probe, comp...By means of total energy calculations within the framework of the local density approximation (LDA), the interactions between a silicon Si(001) surface and a scanning probe are investigated. The tip of the probe, comprising 4 Si atoms scans along the dimer lines above an asymmetric p(2 × 1) surface, at a distance where the chemical interaction between tip-surface is dominant and responsible for image resolution. At that distance, the tip causes the dimer to toggle when it scans above the lower atom of a dimer. The toggled dimers create an alternating pattern, where the immediately adjacent neighbours of a toggled dimer remain unchanged. After the tip has fully scanned across the p(2 × 1) surface, causes the dimers to arrange in a p(2 × 2) reconstruction, reproducing the images obtained in scanning probe experiments. Our modelling methodology includes simulations that reveal the energy input required to overcome the barrier to the onset of dimer toggling. The results show that the energy input to overcome this barrier is lower for the p(2 × 1) surface than that for the p(2 × 2) or c(4 × 2) surfaces.展开更多
In this paper the results of dynamic NMR studies on ethylmethylamino-tertiary-butyl-phenylborane (EMABPB) with or without light are reported. The NMR data were recorded on a Bruker 400 MHz NMR equipped with our custom...In this paper the results of dynamic NMR studies on ethylmethylamino-tertiary-butyl-phenylborane (EMABPB) with or without light are reported. The NMR data were recorded on a Bruker 400 MHz NMR equipped with our custom-made optical probe and with our custom-made 450 watts (W) monochromatic light sources. The molecular photochemistry including twisted intramolecular charge-transfer-excited-state (TICT) of the EMABPB in several solvents has been investigated. These results indicate that the aminoborane demonstrates multiple configurations in CD3Cl and CD2Cl2 resulting in the shifts of the signals of the alkyl groups on the nitrogen and boron. This indicates that there are some time-dependent changes at constant temperature over the irradiation interval. At ﹣60°C and the presence of light (λ = 265 nm), we observed a large change in the populations of the two sites, and this by itself indicates a modification in the rotation around the boron nitrogen bond in the excited state. By considering the existence of the TICT state, many important energy technologies may be developed with higher efficiency by controlling the back-electron transfer processes.展开更多
In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging ...In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging due to the unaffordable cost and high complexity when testing a large number of antennas. To solve this problem, the over-the-air (OTA) test has been presented, in which probe selection is the key to reduce the number of channel emulators and probes. In this paper, a novel artificial bee colony (ABC) algorithm is introduced to enhance the efficiency and accuracy of probe selection procedure. A sectoring- based multi-probe anechoic chamber (MPAC) is built to evaluate the throughput performance of massive MIMO equipped in 5G BS. In addition, link level simulation is carried out to evaluate the proposal’s performance gain under the commercial network assumptions, where the average throughput of three velocity is given with different SNR region. The results suggest that OTA chamber and multi-probe wall are available not only for 5G BSs, but also for user equipments (UEs) with end-to-end communication.展开更多
New ionization and detection techniques in mass spectrometry have been successfully applied for efficient analyses of complex biological systems. It is, however, still difficult to trace structural changes of a specif...New ionization and detection techniques in mass spectrometry have been successfully applied for efficient analyses of complex biological systems. It is, however, still difficult to trace structural changes of a specific molecular species in such systems. In the present study, a molecular probe strategy in combination with tandem electrospray ionization mass spectrometry has been examined using synthetic deuterium-labeled phosphatidylcholine hydroperoxide (PC-OOH/D3) and ethyl-labeled phosphatidylcholine having docosahexaenoic acid side chain (DHA-PC/Et). Administration of a mixture of PC-OOH/D3 and DHA-PC/Et to human blood and human skin surface, followed by extraction and analysis with collision-induced tandem electrospray ionization mass spectrometry demonstrated that metabolites of both molecular probes can be detected simultaneously with strict selectivity. The present method is also found to be useful in tracing chemical changes of the unstable docosahexaenoyl group on the surface of processed fish. The activity of phospholipase A2 can also be assessed using a phospholipid molecular probe with a linoleoyl and a deuteriomethyl group via selective detection of the lyso-phospholipid product by mass spectrometry. The advantage of the present method is that no chromatographic separation is required and analysis can be performed under strictly the same condition for different molecular probes, affording multiple data by one experiment. The present strategy may be useful for tracing time-dependent phenomena in dynamic phospholipid biochemistry, and can be widely used for any biological and food systems.展开更多
Peculiar properties of morphological structures of organelle membranes were studied by fluorescent confocal microscopy. The list of objects in our experiments was represented by mitochondria, chloroplasts and vacuoles...Peculiar properties of morphological structures of organelle membranes were studied by fluorescent confocal microscopy. The list of objects in our experiments was represented by mitochondria, chloroplasts and vacuoles. During this study, identification of lipid microinclusions having the form of such lipid-protein structural microformations as lipid-protein microdomains, vesicles and membrane tubular structures (cytoplasmic transvacuolar strands and nanotubes) located in organelle membranes or bound up with them was conducted. Such membrane probes as laurdan, DPH, ANS and bis-ANS were used. Comparison of fluorescence intensity of these membrane probes was conducted. This investigation of the morphological properties of lipid-protein structural microformations was accompanied with analysis of 1) the phase state and 2) dynamics of microviscosity variations in the membrane elements of isolated plant cell organelles. Distributions of laurdan fluorescence generalized polarization (GP) values for the membrane on the whole and for the intensively fluorescing membrane segments were obtained. It was discovered that the microviscosity of intensively fluorescing membrane segments essentially differed from the microviscosity of the rest part of the membrane. In conclusion, some results of the study of peculiar properties of lipid-protein structural microformations related to the structure of organelle membranes and the discoveries made in this investigation are discussed.展开更多
Bubble plumes are important during the process of air-sea exchange,and optical-fiber phase detection is a suitable way to observe bubble plumes entrained by breaking waves.This paper designs a new optical-fiber probe(...Bubble plumes are important during the process of air-sea exchange,and optical-fiber phase detection is a suitable way to observe bubble plumes entrained by breaking waves.This paper designs a new optical-fiber probe(OFP)made of sapphire to overcome the limitations of existing materials(e.g.,high brittleness,poor corrosion resistance,and narrow bandwidth)and thereby enhance the detection performance of the OFP by improving its structure.Based on total internal reflection and light refraction,a simulation model of the probe is established in the Zemax optical design software to optimize the probe tip and matching mode of the two probe tips.The results show that the optimum OFP tip is a conical sapphire one with a cone angle of 35°.Tests are then conducted on a bespoke OFP sensor,the results of which are consistent with those predicted theoretically.The simulation results lay the foundation for the integrated design of OFP sensors and the optimization of their internal optics.The findings could also be applied to OFPs with multiple tips.展开更多
Objectives: Radix Polygoni Multiflori Praeparata (RPMP) and Dioscorea Bulbifera Rhizomes (DBR) are used in Chinese herbal medicine and have been frequently reported for adverse reactions on liver. In this research, we...Objectives: Radix Polygoni Multiflori Praeparata (RPMP) and Dioscorea Bulbifera Rhizomes (DBR) are used in Chinese herbal medicine and have been frequently reported for adverse reactions on liver. In this research, we aimed to evaluate in vivo effects of RPMP and DBR on rat cytochrome P450 enzymes (CYP1A2, CYP2E1 and CYP3A2) with their respective substrates as probes. Methods: Rats were orally administered RPMP, DBR and RPMP/DBR combination at 12, 10 and (12 + 10) g/kg, respectively, or saline as a control, once daily for 7 days. Thereafter, a cocktail containing 10 mg/kg caffeine, 20 mg/kg chlorzoxazone and 10 mg/kg dapsone was tail vein injected to rats. At defined time points, plasma drug concentrations were simultaneously evaluated by HPLC. Pharmacokinetic parameters simulated by DAS software were used to assess RPMP and/or DBR effects on cytochrome P450 enzymes activity. ANOVA and Dunnett’s test were used for data analysis. Results: Caffeine metabolism was enhanced in RPMP animals and reduced after pretreatment with DBR, but no effect was observed in RPMP/DBR combination group. Chlorzoxazone and dapsone metabolism was enhanced in both RPMP and DBR groups and consequently in combination group. The data suggested that RPMP independently induces rat CYP1A2, CYP2E1 and CYP3A2 activity, while DBR independently inhibits activity of rat CYP1A2 and induces that of CYP2E1 and CYP3A2. RPMP/DBR combination showed no significant benefit compared with the two drugs alone and even showed a neutralized effect in CYP1A2 activity. Conclusions: Caution is needed when RPMP and/or DBR are co-administered with drugs metabolized by human CYP1A2, CYP2E1 and CYP3A4.展开更多
基金This work was supported by National Natural Science Foundation of China(Nos.11435011,11775204,11505170,11405160,11305160)。
文摘The fabrication and absolute calibration of a B-dot probe is employed to measure the pulsed magnetic field at the Shenguang-Ⅱhigh power laser facility.Copper enameled silk with a cross section diameter of 0.1 mm is used to wind the one-turn coil with a 1 mm diameter.Two coils are paired and reversely linked to their respective circuits to form a differential B-dot probe that is sealed in and protected by a quartz shell.This B-dot probe is experimentally calibrated and then used to measure the pulsed magnetic field in laser targeting experiments at the Shenguang-Ⅱhigh power laser facility.Signals show a high performance of this B-dot probe.The common mode noise can be effectively canceled out by the differential pair.The magnetic field of over 300 T can be extrapolated at the location close to the target.
文摘Two significant findings compel a rethink of physical theories. First, using a 7-billion-year-old gamma-ray burst, Nemiroff (2012) showed that quantum foam could not exists. And second, Solomon (2011) showed that gravitational acceleration is not associated with the gravitating mass, that gravitational acceleration g is determined solely by τ the change in time dilation over a specific height multiplied by c2 or g = τc2. Seeking consistency with Special Theory of Relativity, as means to initiate this rethink, this paper examines 12 inconsistencies in physical theories that manifest from empirical data. The purpose of this examination is to identify how gravitational theories need to change or be explored, to eliminate these 12 inconsistencies. It is then proposed that spacetime is much more sophisticated than just a 4-dimensional continuum. And, that the Universe consists of at least two layers or “kenos” (Greek for vacuous), the 4-dimensional kenos, spacetime (x, y, z, t) and the 3-dimensional kenos, subspace (x, y, z) that are joined at the space coordinates (x, y, z). This explains why electromagnetic waves are transverse, and how probabilities are implemented in Nature. This paper concludes by proposing two new instruments and one test, to facilitate research into gravitational fields, the new torsion-, tension- and stress-free near field gravity probe, the gravity wave telescope, and a non-locality test.
文摘Rare earth elements (REEs), especially heavy rare earth elements (HREEs), are in demand for their current and emerging applications in advanced technologies. Here we perform computer-driven micro-mapping at the millimeter scale of the minerals that comprise Round Top Mountain, in west Texas, USA. This large rhyolite deposit is enriched in HREEs and such other critical elements as Li, Be, and U. Electron probe microanalysis of 2 × 2 mm areas of thin sections of the rhyolite produced individual maps of 16 elements. These were superimposed to generate a 16-element composition at each pixel. Principal components analysis of elements at each pixel identified the specific mineral at that site. The pixels were then relabeled as the appropriate minerals, thereby producing a single mineral map. The overall mineral composition of the 7 studied samples compared favorably with prior analyses of the Round Top deposit available in the literature. Likewise the range of porosity in the maps was consistent with that of previous direct measurements by water saturation. This new statistical and GIS-based technique provides a robust and unbiased approach to electron microprobe mapping. The study further showed that the high-value yttrofluorite grains exhibited little tendency to cluster with other late-stage trace minerals and that the samples extended the previously documented overall homogeneity of the deposit at field scale to this microscopic scale.
基金financial support for this work provided by Eski sehir Technical University Scientific Research Projects Unit with Grant Number 20DRP059support provided by the Turkish Ministry of Science,Industry and Technology under the SANTEZ Project 0286.STZ.2013±2。
文摘Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.This investigation incorporated the difference in the‘Work Function'(ΔWF)measured via Kelvin Probe Force Microscopy(KPFM),as a property directly affected by interatomic bond types,i.e.the electronic structure,nanoindentation measurements,and Stacking Fault Energy values reported in the literature.It was shown that the nano-hardness of the solid-solutionα-Mg phase changed in the order of Mg-Ca>Mg-Sr>Mg-Ba.Thus,it was shown,by also considering the nano-hardness levels,that SFE of a solid-solution is closely correlated with its‘Work Function'level.Nano-hardness measurements on the eutectics andΔWF difference between eutectic phases enabled an assessment of the relative bond strength and the pertinent electronic structures of the eutectics in the three alloys.Correlation withΔWF and at least qualitative verification of those computed SFE values with some experimental measurement techniques were considered important as those computational methods are based on zero Kelvin degree,relatively simple atomic models and a number of assumptions.As asserted by this investigation,if the results of measurement techniques can be qualitatively correlated with those of the computational methods,it can be possible to evaluate the electronic structures in alloys,starting from binary systems,going to ternary and then multi-elemental systems.Our investigation has shown that such a qualitative correlation is possible.After all,the SFE values are not treated as absolute values but rather become essential in comparative investigations when assessing the influences of alloying elements at a fundamental level,that is,free electron density distributions.Our study indicated that the principles of‘electronic metallurgy'in developing multi-elemental alloy systems can be followed via practical experimental methods,i.e.ΔWF measurements using KPFM and nanoindentation.
文摘In semiconductor manufacturing process, probe station that is testing equipment is important. Inspection step is for detecting defects on semiconductor before the packaging. Probe card is a part of probe station and contains probe tip that contacts to semiconductor. Through probe tip, it can inspect defects of semiconductor. In this paper, optimization method is used with response surface analysis to design MEMS type probe tip. And fabricating probe tip uses maskless lithography, electro-plating and lapping process.
文摘By means of total energy calculations within the framework of the local density approximation (LDA), the interactions between a silicon Si(001) surface and a scanning probe are investigated. The tip of the probe, comprising 4 Si atoms scans along the dimer lines above an asymmetric p(2 × 1) surface, at a distance where the chemical interaction between tip-surface is dominant and responsible for image resolution. At that distance, the tip causes the dimer to toggle when it scans above the lower atom of a dimer. The toggled dimers create an alternating pattern, where the immediately adjacent neighbours of a toggled dimer remain unchanged. After the tip has fully scanned across the p(2 × 1) surface, causes the dimers to arrange in a p(2 × 2) reconstruction, reproducing the images obtained in scanning probe experiments. Our modelling methodology includes simulations that reveal the energy input required to overcome the barrier to the onset of dimer toggling. The results show that the energy input to overcome this barrier is lower for the p(2 × 1) surface than that for the p(2 × 2) or c(4 × 2) surfaces.
文摘In this paper the results of dynamic NMR studies on ethylmethylamino-tertiary-butyl-phenylborane (EMABPB) with or without light are reported. The NMR data were recorded on a Bruker 400 MHz NMR equipped with our custom-made optical probe and with our custom-made 450 watts (W) monochromatic light sources. The molecular photochemistry including twisted intramolecular charge-transfer-excited-state (TICT) of the EMABPB in several solvents has been investigated. These results indicate that the aminoborane demonstrates multiple configurations in CD3Cl and CD2Cl2 resulting in the shifts of the signals of the alkyl groups on the nitrogen and boron. This indicates that there are some time-dependent changes at constant temperature over the irradiation interval. At ﹣60°C and the presence of light (λ = 265 nm), we observed a large change in the populations of the two sites, and this by itself indicates a modification in the rotation around the boron nitrogen bond in the excited state. By considering the existence of the TICT state, many important energy technologies may be developed with higher efficiency by controlling the back-electron transfer processes.
基金supported by the State Major Science and Technology Special Projects under Grant No. 2018ZX03001028-003
文摘In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging due to the unaffordable cost and high complexity when testing a large number of antennas. To solve this problem, the over-the-air (OTA) test has been presented, in which probe selection is the key to reduce the number of channel emulators and probes. In this paper, a novel artificial bee colony (ABC) algorithm is introduced to enhance the efficiency and accuracy of probe selection procedure. A sectoring- based multi-probe anechoic chamber (MPAC) is built to evaluate the throughput performance of massive MIMO equipped in 5G BS. In addition, link level simulation is carried out to evaluate the proposal’s performance gain under the commercial network assumptions, where the average throughput of three velocity is given with different SNR region. The results suggest that OTA chamber and multi-probe wall are available not only for 5G BSs, but also for user equipments (UEs) with end-to-end communication.
文摘New ionization and detection techniques in mass spectrometry have been successfully applied for efficient analyses of complex biological systems. It is, however, still difficult to trace structural changes of a specific molecular species in such systems. In the present study, a molecular probe strategy in combination with tandem electrospray ionization mass spectrometry has been examined using synthetic deuterium-labeled phosphatidylcholine hydroperoxide (PC-OOH/D3) and ethyl-labeled phosphatidylcholine having docosahexaenoic acid side chain (DHA-PC/Et). Administration of a mixture of PC-OOH/D3 and DHA-PC/Et to human blood and human skin surface, followed by extraction and analysis with collision-induced tandem electrospray ionization mass spectrometry demonstrated that metabolites of both molecular probes can be detected simultaneously with strict selectivity. The present method is also found to be useful in tracing chemical changes of the unstable docosahexaenoyl group on the surface of processed fish. The activity of phospholipase A2 can also be assessed using a phospholipid molecular probe with a linoleoyl and a deuteriomethyl group via selective detection of the lyso-phospholipid product by mass spectrometry. The advantage of the present method is that no chromatographic separation is required and analysis can be performed under strictly the same condition for different molecular probes, affording multiple data by one experiment. The present strategy may be useful for tracing time-dependent phenomena in dynamic phospholipid biochemistry, and can be widely used for any biological and food systems.
文摘Peculiar properties of morphological structures of organelle membranes were studied by fluorescent confocal microscopy. The list of objects in our experiments was represented by mitochondria, chloroplasts and vacuoles. During this study, identification of lipid microinclusions having the form of such lipid-protein structural microformations as lipid-protein microdomains, vesicles and membrane tubular structures (cytoplasmic transvacuolar strands and nanotubes) located in organelle membranes or bound up with them was conducted. Such membrane probes as laurdan, DPH, ANS and bis-ANS were used. Comparison of fluorescence intensity of these membrane probes was conducted. This investigation of the morphological properties of lipid-protein structural microformations was accompanied with analysis of 1) the phase state and 2) dynamics of microviscosity variations in the membrane elements of isolated plant cell organelles. Distributions of laurdan fluorescence generalized polarization (GP) values for the membrane on the whole and for the intensively fluorescing membrane segments were obtained. It was discovered that the microviscosity of intensively fluorescing membrane segments essentially differed from the microviscosity of the rest part of the membrane. In conclusion, some results of the study of peculiar properties of lipid-protein structural microformations related to the structure of organelle membranes and the discoveries made in this investigation are discussed.
文摘Bubble plumes are important during the process of air-sea exchange,and optical-fiber phase detection is a suitable way to observe bubble plumes entrained by breaking waves.This paper designs a new optical-fiber probe(OFP)made of sapphire to overcome the limitations of existing materials(e.g.,high brittleness,poor corrosion resistance,and narrow bandwidth)and thereby enhance the detection performance of the OFP by improving its structure.Based on total internal reflection and light refraction,a simulation model of the probe is established in the Zemax optical design software to optimize the probe tip and matching mode of the two probe tips.The results show that the optimum OFP tip is a conical sapphire one with a cone angle of 35°.Tests are then conducted on a bespoke OFP sensor,the results of which are consistent with those predicted theoretically.The simulation results lay the foundation for the integrated design of OFP sensors and the optimization of their internal optics.The findings could also be applied to OFPs with multiple tips.
文摘Objectives: Radix Polygoni Multiflori Praeparata (RPMP) and Dioscorea Bulbifera Rhizomes (DBR) are used in Chinese herbal medicine and have been frequently reported for adverse reactions on liver. In this research, we aimed to evaluate in vivo effects of RPMP and DBR on rat cytochrome P450 enzymes (CYP1A2, CYP2E1 and CYP3A2) with their respective substrates as probes. Methods: Rats were orally administered RPMP, DBR and RPMP/DBR combination at 12, 10 and (12 + 10) g/kg, respectively, or saline as a control, once daily for 7 days. Thereafter, a cocktail containing 10 mg/kg caffeine, 20 mg/kg chlorzoxazone and 10 mg/kg dapsone was tail vein injected to rats. At defined time points, plasma drug concentrations were simultaneously evaluated by HPLC. Pharmacokinetic parameters simulated by DAS software were used to assess RPMP and/or DBR effects on cytochrome P450 enzymes activity. ANOVA and Dunnett’s test were used for data analysis. Results: Caffeine metabolism was enhanced in RPMP animals and reduced after pretreatment with DBR, but no effect was observed in RPMP/DBR combination group. Chlorzoxazone and dapsone metabolism was enhanced in both RPMP and DBR groups and consequently in combination group. The data suggested that RPMP independently induces rat CYP1A2, CYP2E1 and CYP3A2 activity, while DBR independently inhibits activity of rat CYP1A2 and induces that of CYP2E1 and CYP3A2. RPMP/DBR combination showed no significant benefit compared with the two drugs alone and even showed a neutralized effect in CYP1A2 activity. Conclusions: Caution is needed when RPMP and/or DBR are co-administered with drugs metabolized by human CYP1A2, CYP2E1 and CYP3A4.