scholarly journals Semi-synthetic aequorins with improved sensitivity to Ca2+ ions

1989 ◽  
Vol 261 (3) ◽  
pp. 913-920 ◽  
Author(s):  
O Shimomura ◽  
B Musicki ◽  
Y Kishi
Keyword(s):  
Relative Intensity ◽  
Luminescence Intensity ◽  
Intensity Ratio ◽  
Ratio Method ◽  
Prominent Feature ◽  
Wide Range

Thirty-seven coelenterazine analogues were synthesized and incorporated into apo-aequorin, yielding 30 semi-synthetic aequorins that have the capacity to emit a significant amount of light in the presence of Ca2+. The properties of resultant photoproteins were investigated. The most prominent feature of those photoproteins was the wide range in their sensitivities to Ca2+ concentration. The relative intensity of Ca2+-triggered luminescence of the photoproteins ranged from 0.01 to 190 when compared with natural aequorin (relative intensity 1.0) at pCa 6 for the cases where the relative intensity is less than 1 and at pCa 7 for the cases where the relative intensity is higher than 1. Eight of the semi-synthetic aequorins belonged to the class of e-aequorin. With two of those photoproteins, the degree of dependence of the luminescence intensity ratio I400/I465 on pCa was greater than that with e-aequorin, suggesting that these two photoproteins are possibly superior to e-aequorin in measuring Ca2+ concentration by the ratio method.

scholarly journals HCN-to-HNC intensity ratio: a new chemical thermometer for the molecular ISM

2020 ◽  
Vol 635 ◽  
pp. A4 ◽  
Author(s):  
A. Hacar ◽  
A. D. Bosman ◽  
E. F. van Dishoeck
Keyword(s):  
Intensity Ratio ◽  
Large Scale ◽  
Temperature Measurements ◽  
Kinetic Temperature ◽  
Physical Conditions ◽  
Chemical Models ◽  
Dust Temperature ◽  
Empirical Calibration ◽  
Wide Range ◽  
Physical And Chemical

Context. The gas kinetic temperature (TK) determines the physical and chemical evolution of the interstellar medium (ISM). However, obtaining reliable TK estimates usually requires expensive observations including the combination of multi-line analysis and dedicated radiative transfer calculations. Aims. This work explores the use of HCN and HNC observations, and particularly the I(HCN)-to-I(HNC) intensity ratio (I(HCN)/I(HNC)) of their J = 1–0 lines, as direct probe of the gas kinetic temperature in the molecular ISM. Methods. We obtained a new set of large-scale observations of the HCN and HNC (1–0) lines throughout the Integral Shape Filament (ISF) in Orion. In combination with ancillary gas and dust temperature measurements, we find a systematic temperature dependence of the observed I(HCN)-to-I(HNC) intensity ratio throughout our maps. Additional comparisons with chemical models demonstrate that these observed I(HCN)/I(HNC) variations are driven by the effective destruction and isomerization mechanisms of HNC under low-energy barriers. Results. The observed variations of I(HCN)/I(HNC) with TK can be described with a two-part linear function. This empirical calibration is then used to create a temperature map of the entire ISF. Comparisons with similar dust temperature measurements in this cloud, as well as in other regions and galactic surveys, validate this simple technique for obtaining direct estimates of the gas kinetic temperature in a wide range of physical conditions and scales with an optimal working range between 15 K ≲ TK ≤ 40 K. Conclusions. Both observations and models demonstrate the strong sensitivity of the I(HCN)/I(HNC) ratio to the gas kinetic temperature. Since these lines are easily obtained in observations of local and extragalactic sources, our results highlight the potential use of this observable as new chemical thermometer for the ISM.

Controls of Crystallinity and Surface Roughness of Cu Film in Partially Ionized Beam Deposition

1995 ◽  
Vol 396 ◽  
Author(s):  
Seok-Keun Koh ◽  
Ki-Hwan Kim ◽  
Won-Kook Choi ◽  
Hong-Gui Jang ◽  
Young-Soo Yoon ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ionization Potential ◽  
Relative Intensity ◽  
Intensity Ratio ◽  
Ion Beam ◽  
Average Energy ◽  
Relative Intensity Ratio ◽  
Cu Films ◽  
Acceleration Potential ◽  
Residual Gas

AbstractChanges of crystallinity and surface roughness are discussed in terms of the average energy per deposited atom in the partially ionized beam(PIB) deposition. The average energy per deposited atom can be controlled by adjusting the ionization potential, Vi and acceleration potential, Va. The ion beam consists of a Cu ion beam and residual gas ion beam and residual gases as well as Cu particles that were ionized and accelerated to provide the film with energy required for film-growth. The relative contribution of residual gas ions and Cu ions to total average energy per deposited atom was varied with the ionization potential. At fixed ionization potentials of Vi=400 V and Vi=450 V, the average energy per deposited atom was varied in the range of 0 to 120 eV with acceleration potential Va, of 0 to 4 kV. The relative intensity ratio, 1(111)/I(200), of the Cu films increased from 6 to 37 and the root mean square(Rms) surface roughness decreased with an increase in acceleration potential at Vi=400 V. The relative intensity ratio, I(lll)/I(200), of Cu films increased up to Va=2 kV at Vi=2 kV, above which a decrease occurred, and the surface roughness of Cu films increased as a funtion of acceleration potential. The degree of preferred orientation was closely related with the average energy per deposited atom. The change of Rms roughness might be affected by ion flux, particle energy and preferred orientation.

scholarly journals Raman Spectroscopy Analysis of Free Fatty Acid in Olive Oil

2019 ◽  
Vol 9 (21) ◽  
pp. 4510
Author(s):  
Jin Qiu ◽  
Hua-Yi Hou ◽  
In-Sang Yang ◽  
Xiang-Bai Chen
Keyword(s):  
Raman Spectroscopy ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Olive Oil ◽  
Relative Intensity ◽  
Intensity Ratio ◽  
Green Laser ◽  
Critical Parameters ◽  
Vibrational Modes ◽  
Relative Intensity Ratio

Free fatty acid (FFA) is one of the most critical parameters for evaluating the quality of olive oil. In this paper, we present a simple and rapid Raman spectroscopy method for analyzing free fatty acid in olive oil. First, FFA degradation of carotenoids in olive oil is confirmed by analyzing the relative intensity of characteristic vibrational modes and introducing an intensity decrease factor. Second, it is demonstrated that the relative intensity ratio of the two characteristic vibrational modes at 1525 cm−1 and 1655 cm−1 presents a good and rapid analysis of FFA content in olive oil; the relative intensity ratio decreases linearly with FFA content. In addition, resonance Raman scattering of carotenoid is discussed, showing that a green laser should be utilized to study FFA in olive oil.

Full-aperture gain measurement of diode-pumped Nd:YAG slab laser amplifier with intensity ratio method

2017 ◽  
Vol 71 ◽  
pp. 27-30
Author(s):  
Guangyan Guo ◽  
Zhongwei Fan ◽  
Yanzhong Chen ◽  
Dan Jia ◽  
Weiran Lin ◽  
...  
Keyword(s):  
Intensity Ratio ◽  
Ratio Method ◽  
Laser Amplifier ◽  
Slab Laser ◽  
Gain Measurement ◽  
Diode Pumped

Physical modeling and analysis of P-wave attenuation anisotropy in transversely isotropic media

Geophysics ◽  
2007 ◽  
Vol 72 (1) ◽  
pp. D1-D7 ◽  
Author(s):  
Yaping Zhu ◽  
Ilya Tsvankin ◽  
Pawan Dewangan ◽  
Kasper van Wijk
Keyword(s):  
Attenuation Coefficient ◽  
Symmetry Axis ◽  
Wave Attenuation ◽  
Transversely Isotropic ◽  
P Wave ◽  
Velocity Variation ◽  
Ratio Method ◽  
Fracture Detection ◽  
Wide Range ◽  
Attenuation Anisotropy

Anisotropic attenuation can provide sensitive attributes for fracture detection and lithology discrimination. This paper analyzes measurements of the P-wave attenuation coefficient in a transversely isotropic sample made of phenolic material. Using the spectral-ratio method, we estimate the group (effective) attenuation coefficient of P-waves transmitted through the sample for a wide range of propagation angles (from [Formula: see text] to [Formula: see text]) with the symmetry axis. Correction for the difference between the group and phase angles and for the angular velocity variation help us to obtain the normalized phase attenuation coefficient [Formula: see text] governed by the Thomsen-style attenuation-anisotropy parameters [Formula: see text] and [Formula: see text]. Whereas the symmetry axis of the angle-dependent coefficient [Formula: see text] practically coincides with that of the velocity function, the magnitude of the attenuation anisotropy far exceeds that of the velocity anisotropy. The quality factor [Formula: see text] increases more than tenfold from the symmetry axis (slow direction) to the isotropy plane (fast direction). Inversion of the coefficient [Formula: see text] using the Christoffel equation yields large negative values of the parameters [Formula: see text] and [Formula: see text]. The robustness of our results critically depends on several factors, such as the availability of an accurate anisotropic velocity model and adequacy of the homogeneous concept of wave propagation, as well as the choice of the frequency band. The methodology discussed here can be extended to field measurements of anisotropic attenuation needed for AVO (amplitude-variation-with-offset) analysis, amplitude-preserving migration, and seismic fracture detection.

scholarly journals Recombinant aequorin and recombinant semi-synthetic aequorins. Cellular Ca2+ ion indicators

1990 ◽  
Vol 270 (2) ◽  
pp. 309-312 ◽  
Author(s):  
O Shimomura ◽  
S Inouye ◽  
B Musicki ◽  
Y Kishi
Keyword(s):  
Luminescence Intensity ◽  
Intensity Ratio ◽  
Synthetic Analogues ◽  
Chromatographic Behaviour ◽  
Recombinant Aequorin

Properties of a recombinant aequorin were investigated in comparison with those of natural aequorin. In chromatographic behaviour the recombinant aequorin did not match any of ten isoaequorins tested, although it was very similar to aequorin J. Its sensitivity to Ca2+ was found to be higher than that of any isoaequorin except aequorin D. The recombinant aequorin exhibited no toxicity when tested in various kinds of cells, even where samples of natural aequorin had been found to be toxic. Properties of four recombinant semi-synthetic aequorins (fch-, hcp-, e- and n-types), prepared from the recombinant apo-aequorin and synthetic analogues of coelenterazine, were approximately parallel with those of corresponding semi-synthetic aequorins prepared from natural apo-aequorin. Both recombinant e-aequorin and natural e-aequorin J luminesced with high values of the luminescence intensity ratio I400/I465, although the ratios were not pCa-dependent. The recombinant aequorin and recombinant semi-synthetic aequorins are highly suited for monitoring cellular Ca2+.

Custom-built thermometry apparatus and luminescence intensity ratio thermometry of ZrO2:Eu3+ and Nb2O5:Eu3+

2019 ◽  
Vol 30 (4) ◽  
pp. 045001 ◽  
Author(s):  
Aleksandar Ćirić ◽  
Stevan Stojadinović ◽  
Miroslav D Dramićanin
Keyword(s):  
Luminescence Intensity ◽  
Intensity Ratio

Comparing the performance of Nd3+-doped LiBaPO4 phosphors as optical temperature sensors within the first biological window exploiting luminescence intensity ratio and bandwidth methods

2020 ◽  
Vol 227 ◽  
pp. 117524
Author(s):  
André Scheidegger Laia ◽  
Daniela A. Hora ◽  
Marcos V. dos S. Rezende ◽  
Yutao Xing ◽  
José Joatan Rodrigues ◽  
...  
Keyword(s):  
Luminescence Intensity ◽  
Intensity Ratio ◽  
Temperature Sensors
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