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.     

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.     

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.     

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.     

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.     

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).     

Specific Features of the Quasilocal State Densities in the Presence of Defects in Media with Spatial Dispersion

The density of stationary quasilocal states of the continuous spectrum arising due to the presence of defects in a medium with spatial dispersion is analyzed. The influence of plane and point defects on the specific features of the spectral quasilocal state density is studied. It is demonstrated that the spectral density has a strict maximum caused by the quasilocal energy level arising in the system. For a plane defect, the energy of the quasilocal level is displaced from the resonance energy of total quasi-particle reflection from the defect. The influence of the quasilocal state on the electronic heat capacity in the presence of the point defect is analyzed.     

High accuracy Dirac-finite-element (FEM) calculations for H 2 + and Th 2 179 +

A two-dimensional, fully numerical approach to the four-component first-order Dirac-differential-equation utilizing the Finite-Element-Method (FEM) is employed for H ₂ ⁺ and Th ₂ ^{179 +} . Using elliptic-hyperbolic coordinates and further one-dimensional singular transformations, scaling transformations and extrapolation techniques (geometrical over iteration steps and logarithmic over grid points) we achieve for the molecules H ₂ ⁺ and Th ₂ ^{179 +} relative accuracies better than 10^-12 for 1(1/2) g energies. Received 16 February 2001 and Received in final form 12 July 2001     

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.     

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.     

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.     

First Observation of the nu(17)-nu(4) Difference Bands of Diborane (10)B(2)H(6) and (11)B(2)H(6)

An analysis of the nu(17)-nu(4) difference bands near 800 cm(-1) of two isotopic species, (10)B(2)H(6) and (11)B(2)H(6), of diborane has been carried out using infrared spectra recorded with a resolution of ca. 0.003 cm(-1). In addition, the nu(17) band of (10)B(2)H(6) has been recorded and assigned. Since this band in (11)B(2)H(6) had already been studied (R. L. Sams, T. A. Blake, S. W. Sharpe, J.-M. Flaud, and W. J. Lafferty, J. Mol. Spectrosc. 191, 331-342 (1998)), it was possible to derive precise energy levels and Hamiltonian constants for the 4(1) vibrational states of both isotopic species. Copyright 2000 Academic Press.     

13C NMR and 2D (H,H and H,C COSY) Spectra of Triazolo-triazino-indole Derivatives and the Conformational Analysis of the Respective C-Nucleoside Analogues

¹³C NMR and 2D (H,H and H,C COSY) spectra of selected examples of sugar (5H-1,2,4-triazino[5,6-b]-indol-3-yl) hydrazones, peracetylated sugar-1-acetyl -1- (5-acetyl-1,2,4-triazino[5,6-b]indol-3-yl)hydrazones, and 10-acetyl-3-(per-0-acetylalditol-1-yl)-1,2,4-triazolo[4′, 3′:2,3][1,2,4]triazino[5,6-b]indole have been reported. The conformation of the latter C-nucleoside analogues have been determined by analysis of their ¹H NMR spectra. The D-galacto, D-manno and L-arabino isomers are preponderantly existing in the planar zigzag arrangement of carbon atoms.     

Equivalence of the (Generalised) Hadamard and Microlocal Spectrum Condition for (Generalised) Free Fields in Curved Spacetime

We prove that the singularity structure of all n-point distributions of a state of a generalised real free scalar field in curved spacetime can be estimated if the two-point distribution is of Hadamard form. In particular this applies to the free field and the result has applications in perturbative quantum field theory, showing that the class of all Hadamard states is the state space of interest. In our proof we assume that the field is a generalised free field, i.e. that it satisfies scalar (c-number) commutation relations, but it need not satisfy an equation of motion. The same arguments also work for anti-commutation relations and for vector-valued fields. To indicate the strengths and limitations of our assumption we also prove the analogues of a theorem by Borchers and Zimmermann on the self-adjointness of field operators and of a weak form of the Jost-Schroer theorem. The original proofs of these results make use of analytic continuation arguments. In our case no analyticity is assumed, but to some extent the scalar commutation relations can take its place.     

Probing spin-orbit quenching in Cl (2P) + H2 via crossed molecular beam scattering

In our previous work we investigated electronically non-adiabatic effects in using crossed molecular beam scattering coupled with velocity mapped ion imaging. The prior experiments placed limits on the cross-section for electronically non-adiabatic spin-orbit excitation and electronically non-adiabatic spin-orbit quenching . In the present work, we investigate electronically non-adiabatic spin-orbit quenching for which is the required first step for the reaction of Cl^* to produce ground state HCl+H products. In these experiments we collide Cl (²P) with H₂ at a series of fixed collision energies using a crossed molecular beam machine with velocity mapped ion imaging detection. Through an analysis of our ion images, we determine the fraction of electronically adiabatic scattering in Cl^* +H₂, which allows us to place limits on the cross-section for electronically non-adiabatic scattering or quenching. We determine the following quenching cross-sections σ _quench(2.1 kcal/mol) = 26 ± 21 ?², σ _quench(4.0 kcal/mol) = 21 ± 49 ?², and σ _quench(5.6 kcal/mol) = 14 ± 41 ?².     

Doubly-Excited 1,3 P o States of H− Interacting with Screened Coulomb (Yukawa) Potentials

We have investigated the doubly excited 2s2p ³ P ^o and 2s3p ¹ P ^o resonance states of H⁻ embedded in a model plasma environment. Plasma effects are taken care of by using a screened Coulomb (Yukawa-type) potential. Correlated wave functions are used to represent the correlation effect between the charged particles. The density of resonance states has been calculated using the stabilization method. The calculated resonance energies and widths for various screening parameters are reported.     

Semi-constant-time HMSQC (SCT-HMSQC-HA) for the measurement of (3)J(H(N))(H(alpha)) couplings in (15)N-labeled proteins

A simple method for accurately measuring (3)J(H(N))(H(alpha)) coupling constants in (15)N-labeled proteins is described. This semi-constant-time HMSQC-HA experiment combines the rapidity and convenience of the recently introduced CT-HMQC-HA scheme (Postingl and Otting, J. Biomol. NMR 12, 319-324 (1998)) with the high resolution and robustness of the HSQC experiment. The proposed method is demonstrated for the 76-residue human ubiquitin and Saccharopolyspora erythraea calerythrin (176 residues). Our results imply that the SCT-HMSQC-HA experiment is suitable also for proteins with less favorable NMR properties due to its good resolution and sensitivity.     

Experimental Consequences of the Asymptotically Free SU(5)-Model

The experimental consequences of the asymptotically free SU(5)-theory are presented which make it possible to judge about its reliability. The phenomenology of the τ-lepton is analysed with special attention paid to the so-called exotic processes which must solve whether “light” or “heavy” the ν_τ-neutrino should be. These exotic processes are completely forbidden within standard SU(5) schemes. The problem of the finite mass of the e, μ-neutrino which is a four-component Dirac spinor interacting via the Zel'dovitch-Mahmound-Konopinski scheme is discussed. The finiteness of such neutrino mass is a peculiarity of the SU(5) theory under discussion, although its value is not fixed here in a unique way. The version of the theory wherein m_ν ≦ 10⁻³ eV is of especial interest since in this case the proton instability and the finite e, μ-neutrino mass are found to be explained in a common way as manifestations of the existence of superheavy leptoquark bosons in the theory. The possibility is pointed out to explain within the SU(5) theory under consideration the existing experimental situations concerning the search for parity violating effects in atoms. It is shown that the present SU(5) theory encounters no difficulty in this respect and can recommend itself to any experimental set of data, whereas the standard schemes of SU(5) unification cannot. Cosmological consequences of the asymptotically free SU(5) theory are briefly discussed and the latter is found to rather reasonably explain a number of facts about the very early evolution of the Universe.