Determination of NAD(P)H by A Bioluminescent Enzyme Fiber Optic Probe

Abstract

A fiber optic probe was interfaced to a photon counting system for the determination of nicotinamide adenine dinucleotide reduced [NAD(P)H] by a bioluminescence method. The reagents employed in a bacterial luciferase/flavin mononucleotide /decanal system were optimized. Attempts were made to increase the quantum yield of the system. Dodecanal, tridecanal, and tetradecanal were evaluated as alternative aldehyde reagents for decanal, and hydrogen peroxide was added to the system. Neither attempt increased the quantum yield of the system. However, a relatively low detection limit of 1.6 × 10^?9 M for NAD(P)H was obtained with a linear dynamic range of 3.8 orders of magnitude. These results demonstrate the sensitivity of this instrumentation and assay.     

High Energy P+P(P)→P+P(P)+Xj(cc) Process and Two Methods for Calculating Double-Pomeron Exchange Mechanism

Using the X_j(cc) double diffractive production processes in high energy P + P(P) collisions, we have comparatively discussed the D-L phenomenological method of calculating the double-pomeron exchange (DPE) and the method based on the exchange of a pair of nonperturbative color singlet gluons. From the energy dependence of the total cross sections calculated with the two methods we find the two methods fitting well. We conclude that the two methods are consistent.     

A Vibrational Normal Coordinate Analysis of H(D)NCO and H(D)NCS

The infrared spectra of HNCO and HNCS are quite complicated and the band assignments are still disputed. In this note we try to add some arguments based on the normal coordinate analysis in favour of the recently proposed assignments^1,2. The analysis was performed by the standard GF method with the frequency assignment due to Ashby and Werner¹ for HNCO, and Durig and Wertz for HNCS². The frequencies only were used in the iteration procedure and the results are given in the Table.     

Free energy and torque for superconductors with different anisotropies of H(c2) and lambda

The free energy is evaluated for a uniaxial superconductor with the anisotropy of the upper critical field, gamma(H)=H(c2,a)/H(c2,c), different from the anisotropy of the penetration depth gamma(lambda)=lambda(c)/lambda(a). With increasing difference between gamma(H) and gamma(lambda), the equilibrium orientation of the crystal relative to the applied field may shift from theta=pi/2 (theta is the angle between the field and the c axis) to lower angles and reach theta=0 for large enough gamma(H). These effects are expected to take place in MgB2.     

Theoretical study of stereodynamics for the O（3P） ＋ H2 → OH ＋ H reaction

This paper employs the quasi-classical trajectory calculations to study the influence of collision energy on the title reaction on the potential energy surface of the ground ³A' triplet state developed by Rogers et al. (J. Phys. Chem. A 2000 104 2308). It calculates the product angular distribution of P(θ_r), P(φ_r) and P(θ_r, φ_r) which reflects vector correlation. The distribution P(θ_r) shows that product rotational angular momentum vectors j' of the products are strongly aligned along the relative velocity direction k. The distribution of P(φ_r) implies a preference for left-handed product rotation in planes parallel to the scattering plane. Four different polarisation-dependent cross-sections are also presented in the centre-of-mass frame. Results indicate that OH is sensitively affected by collision energies of H₂.     

31P and 2H NMR study of MZr2(PO4)3

²H NMR spectra of (N²H₄)Zr₂(PO₄)₃ and (²H₃O)Zr₂(PO₄)₃ indicate that the cation in these compounds is under going a fast anisotropic reorientation over a wide temperature range 173–373 K. The short T_PH in the ³¹P cross polarisation suggest that diffusion of the cation between M1 and M2 sites is not occuring and hence the motion is likely to be a reorientation within its lattice site.     

Collision-induced dissociation of H 2 + ions into the fragmentations H+H(2p) and H++H(2p)

Using a photon-particle delayed coincidence method the energy distributions of H +H(2p) and H⁺+H(2p) fragment pairs have been measured arising from collisional dissociation of 10 keV H ₂ ⁺ ions incident on various target gases. H fragments in their 2p state are identified by the Lymanα radiation emitted. The distribution of H+H(2p) fragment pairs arising from dissociative charge exchange reveals a sharp increase below 0.2 eV in the center-of-mass frame of the H ₂ ⁺ ion. This is ascribed to predissociation of vibrational levels of higher H₂ Rydberg states close above then=2 dissociation limit by those H₂ Rydberg states which separate into H+H(2p) fragments. Only direct transitions into the continuum of theGK ¹ ∑ _g ⁺ state may compete. Some structure at 0.3–0.5 eV is attributed to the three statesI ¹ П _g,i ³ П _g, andh ³ bE _g ⁺ having potential barriers of this height. The distributions for H⁺+H(2p) have maxima at 3.4, 3.8, and 4.2 eV for a H₂, Ar, and He target, respectively, indicating that the 2pπ _u state as well as the 3dσ _g state ofH ₂ ⁺ is excited. The H+H(2p) process has a greater probability than the H⁺+H(2p) process for Ar and H₂ targets, though all electronic H₂ states under consideration are bound.     

Ortho- to Para-Hydrogen Conversion and Molecular Diffusion in the High Pressure Compound Ar(H 2 ) 2

Ortho-para hydrogen conversion kinetics has been measured in the stoichiometric Ar(H 2 ) 2 compound, at pressures from 3 to 35 GPa, from the intensity of the rotational Raman transitions. The conversion rate increases with pressure by almost a factor 50 in the investigated pressure range. A comparison is made with pure hydrogen, where a similar increase is also observed. For long times and low ortho concentration, the conversion kinetic deviates from the law derived for uniform distribution of the ortho-hydrogen molecules in the crystal. The magnitude of this effect, due to the limited diffusion rate of the hydrogen molecules in the crystal, allows the measurement of the diffusion coefficient.     

K(5P)与H2的反应碰撞和电子-振动能量转移

K(5P)与H2反应生成KH(v′′=0-3)振动态,测量了各振动态的转动分布,转动玻尔兹曼温度为455K,而振动温度为1604K,这个接近池温的转动温度和很高的振动温度是共线碰撞机制的有力证据.利用高分辨率瞬时吸收技术得到各振动能级上转动态的布居分布,从而得到反应碰撞转移速率系数,对于v′′=0、1、2、3,分布别为(3.45±0.86)×10-13、(1.35±0.34)×10-13、(6.28±1.57)×10-14和(2.35±0.59)×10-14cm3s-1. 同时研究了K(5P)-H2的电子-振动能量转移,利用相干反斯托克斯拉曼散射（CARS）探测H2的振动态分布.扫描CARS谱发现v=1、2、3上有布居. 由CARS峰值得到H2（0,1）、（1,1）、（2,1）、（3,1）和（3,3）布居之比. H2(0,1)布居由450K的转动分布得到,因而得到（1,1）、（2,1）、（3,1）和（3,3）态的布居,从而获得K(5P)-H2(1,1)、（2,1）、（3,1）和（3,3）的电子-振转速率系数分别是（1.1±0.3）×10-13、（9.3±2.5）×10-14、（4.2±1.1）×10-14和（3.8±1.0）×10-14cm3s-1.     

Some Anisotropic Universes in the Presence of Imperfect Fluid Coupling with Spatial Curvature

We consider Bianchi VI spacetime, which also can be reduced to Bianchi types VI₀-V-III-I. We initially consider the most general form of the energy-momentum tensor which yields anisotropic stress and heat flow. We then derive an energy-momentum tensor that couples with the spatial curvature in a way so as to cancel out the terms that arise due to the spatial curvature in the evolution equations of the Einstein field equations. We obtain exact solutions for the universes indefinitely expanding with constant mean deceleration parameter. The solutions are beriefly discussed for each Bianchi type. The dynamics of the models and fluid are examined briefly, and the models that can approach to isotropy are determined. We conclude that even if the observed universe is almost isotropic, this does not necessarily imply the isotropy of the fluid (e.g., dark energy) affecting the evolution of the universe within the context of general relativity.     

共聚物P(VDF-TrFE)在高压下的电学性质与相变

 研究了共聚物P（VDF-TrFE）（物质的量分数分别为80%、20%）在室温下、14 GPa内的电容、电阻与压力的关系。实验结果表明，它在14 GPa内存在两个相交：第一个相变发生在1.1 GPa左右；而第二个相变发生在5～6 GPa左右。     

Torsional Splitting in the Degenerate Vibrational States of (70)Ge(2)H(6): Rotation-Torsion Analysis of the nu(7) and nu(9) Fundamentals

The rotational and torsional structure of the nu(7) and nu(9) degenerate fundamentals of (70)Ge(2)H(6) has been analyzed under high resolution. The torsional structure of both v(7) = 1 and v(9) = 1 states can be fitted by a simple one-parameter formula. The x,y-Coriolis interaction with the parallel nu(5) fundamental was accounted for in the analysis of nu(7). A strong perturbation of the J structure of the E(3s) torsional component of the KDeltaK = -2 subbranches of nu(9) can be explained by the resonance with an E(3s) excited level of the pure torsional manifold. The perturber is centered at 361.58 cm(-1), very close to the value estimated with a barrier height of 285 cm(-1). This confirms that the fundamental torsional wavenumber is close to 103 cm(-1), in good agreement with the "ab initio" prediction. The torsional splittings of all the infrared active degenerate fundamentals, nu(7), nu(8), and nu(9), follow the trend predicted by theory, and have been fitted by exploratory calculations accounting only for the torsional Coriolis-coupling mechanism of all degenerate vibrational fundamentals in several torsional states. This confirms that torsional Coriolis coupling is the dominant mechanism responsible for the decrease of the torsional splitting in the degenerate vibrational states. A higher value of the barrier had to be used for the nu(9) mode. Copyright 2000 Academic Press.     

Hydrothermal Synthesis at High Pressure and Temperature of the Mg 7.5 Ni 6 H 3 (AsO 4 ) 8 (OH) 6 and Mg 8 Ni 4 H 6 (PO 4 ) 8 (OH) 6 Compounds

The Mg 7.5 Ni 6 H 3 (AsO 4 ) 8 (OH) 6 and Mg 8 Ni 4 H 6 (PO 4 ) 8 (OH) 6 compounds have been synthesized by using hydrothermal techniques at high pressure and temperature. The crystal structure of the arsenate phase has been refined with the Rietveld method. The compounds are isostructural. The structure consists of a three-dimensional framework in which the presence of triangular and hexagonal channels is observed. Reflectance diffuse measurements confirm the hexacoordination of the Ni(II) ions in both compounds. The magnetic behaviour indicates the presence of antiferromagnetic interactions between the Ni(II) ions placed in the double chains.     

First observation of the P-wave spin-singlet bottomonium states hb(1P) and hb(2P)

We report the first observations of the spin-singlet bottomonium states h(b)(1P) and h(b)(2P). The states are produced in the reaction e(+)e(-)→h(b)(nP)π(+)π(-) using a 121.4 fb(-1) data sample collected at energies near the Υ(5S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We determine M[h(b)(1P)]=(9898.2(-1.0-1.1)(+1.1+1.0)) MeV/c(2) and M[h(b)(2P)]=(10,259.8±0.6(-1.0)(+1.4)) MeV/c(2), which correspond to P-wave hyperfine splittings ΔM(HF)=(+1.7±1.5) and (+0.5(-1.2)(+1.6)) MeV/c(2), respectively. The significances of the h(b)(1P) and h(b)(2P) are 5.5σ and 11.2σ, respectively. We find that the production of the h(b)(1P) and h(b)(2P) is not suppressed relative to the production of the Υ(1S), Υ(2S), and Υ(3S).     

高通量傅里叶变换成像光谱仪调制度分析

介绍了高通量傅里变换成像光谱仪的概念,分析了其中使用的改进型Mach-Zehnder干涉仪的原理,计算出其光程差以及调制度.可以看出:要得到较好的调制图形,必须满足两像面夹角和像方孔径角都是小角的条件,且两个像点之间的横向距离和纵向距离越小越好.讨论了像面与探测器平面之间的横向和纵向偏差及CCD单元尺寸等因素对光谱仪调制度的影响.通过调节各参量,三种调制度都可以达到90％以上,能够满足光谱仪应用需求.     

Effective Lagrangian of SU（2） Yang—Mills Theory in the Presence of Fermions

We derive the one-loop effective action of SU(2) Yang-Mills theory in the presence of fermions in the low energy limit.This result is presented by separating the topological degrees,which describe the non-Abelian monopoles from the dynamical degrees of the gauge potential and integrate out all the dynamical degrees and fermions in SU(2) Yang-Mills theory.     

Dynamic1H,13C,31P NMR spectroscopy of the crown containing N-(thio)phosphoryl(thio)urea

The variable temperature and concentration¹H,¹³C,³¹P NMR spectroscopy of the N,N′-bis[diisopropoxy(thio)phosphorylamido-(thio)carbonyl]-1,10-diaza-18-crown-6 containing the reaction pentade C(X)NHP(Y) and stereononrigid macrocycle in solutions (CD₂CL₂, CD₃CN, (CD₃)₂CO as solvent) was studied. The complex chemical exchange is described in terms of tautomeric processes, hindered rotation around C-N bond and macrocycle ring inversion. NMR spectral parameters (chemical shifts and spin-spin coupling constants) of the observed exchange partners as well as thermodynamic parameters of the equilibrium and transition between tautomeric and conformational forms are given.     

Optical studies of the ferroelastic phase transitions in Rb3H(SeO4)2, (NH4)3H(SO4)2 and (NH4)3H(SeO4)2

Optical observations of growth twins and ferroelastic domains and measurements of the rotation of the optical indicatrix were carried out for Rb₃H(SeO₄)₂ and (NH₄)₃H(SO₄)₂ using an optical microscope. Taking into account the symmetry reduction from the rhombohedral (Rm) to the monoclinic phase (B2/a) the occurrence of domains and growth twins can be well described. The orientations of oblique ferroelastic walls are well determined by the spontaneous strains ^s e ₁₁ and ^s e ₂₃ at room temperature.     

Absolute Intensities Measurements in the nu(4) + nu(5) Band of (12)C(2)H(2): Analysis of Herman-Wallis Effects and Forbidden Transitions

We measured absolute line intensities in two bands of (12)C(2)H(2) near 7.5 μm, namely the nu(4) + nu(5)(Sigma(+)(u))-0(Sigma(+)(g)) and nu(4) + nu(5)(Delta(u))-0(Sigma(+)(g)) bands, using Fourier transform spectroscopy with an accuracy estimated to be better than 2%. Using theoretical predictions from Watson [J. K. G. Watson, J. Mol. Spectrosc. 188, 78 (1998)], the observation of the forbidden nu(4) + nu(5)(Delta(u))-0(Sigma(+)(g)) band and the Herman-Wallis behavior exhibited by its rotational lines were studied quantitatively in terms of two types of interactions affecting the levels involved by the band: l-type resonance and Coriolis interaction. In the case of the nu(4) + nu(5)(Sigma(+)(u))-0(Sigma(+)(g)) band, the influence of l-type resonance is also confirmed. We also attributed the intensity asymmetry observed between the R and P branches of that latter band to a Coriolis interaction with l = 1 levels. We did not observe the nu(4) + nu(5)(Sigma(-)(u))-0(Sigma(+)(g)) band, consisting only of a Q branch, in agreement with Watson's prediction. Copyright 2000 Academic Press.