Doppler-free high resolution spectroscopy of carbon disulphide and the effects of a magnetic field

A single-mode autoscan laser spectrometer operating in the ultraviolet in combination with a collimated molecular beam was used to measure high resolution fluorescence excitation spectra of the CS₂ V ¹B₂ ← X ¹Σ⁺ _g transition under collision-free conditions, and the effects of a magnetic field were measured. Rotational and vibrational levels were fully resolved, and Zeeman splittings were observed in many of the perturbed lines. The Zeeman interaction was observed to induce new perturbation, which induces new transitions, level splitting, and energy shift. When the magnetic field strength was changed, the magnitude of the interaction, which was observed in the absence of a magnetic field, changed dramatically depending on the energy shifts of the Zeeman components. It is shown that the V ¹B₂(¹Δ_u) state is mixed with the B₂(³A₂) component by first-order spin-orbit interaction, and through the mixed component, the Zeeman interaction between the V ¹B₂(¹Δ_u) and ³A₂(³Δ_u) states is induced. Large Zeeman splittings were observed for most of the background lines of weak intensity, and this demonstrates that the background levels are levels of the ³A₂(³Δ_u) state. The fluorescence decays of single Zeeman components were observed to be single exponential. The lifetimes of the perturbing ³A₂(³Δ_u) levels were determined by deperturbation analysis. Triplet-triplet ³A₂(³Δ_u) → ³B₂(³Σ⁺ _u) emission was confirmed. It was demonstrated that the quenching of the V ¹B₂ → X ¹Σ⁺ _g fluorescence by a magnetic field was caused by mixing of the ³A₂ state with the V ¹B₂ state and the resulting increase of triplet-triplet emission. In a time-dependent picture, the intersystem crossing from the ¹B₂(¹Δ_u) and ³A₂(³Δ_u) states is enhanced by the magnetic field.     

Stability of Frobenius pull-backs of tangent bundles and generic injectivity of Gauss maps in positive characteristic

For a smooth projective variety X of dimension n in a projective space defined over an algebraically closed field k, the Gauss mapis a morphism from X to the Grassmannian of n-plans in sending to the embedded tangent space .The purpose of this paper is to prove the generic injectivity of Gauss mapsin positive characteristic for two cases; (1) weighted complete intersectionsof dimension of general type; (2) surfaces or 3-folds with -semistable tangent bundles; based on a criterion of Kaji by looking atthe stability of Frobenius pull-backs of their tangent bundles. The first result implies that a conjecture of Kleiman--Piene is true in case X is of general type of dimension . The second result is a generalization of the injectivity for curves.     

Wavepacket dynamics and quantum mechanical energy densities in the quartet N+ 2 + O2 system

Surface crossing of the potential energy surfaces (PESs) and the formulation of differentiable PES functions are discussed in the quartet N⁺ ₂ + O₂ system containing the T shape intermediate complex. Consideration of the ion-dipole interaction between N₂ and O₂ fragments due to the induced dipole moment of the neutral molecule gives a good image of the surface crossing between the quartet reactant state (N⁺ ₂ ···O₂) and the quartet product state (N₂ ···O⁺ ₂) for the charge transfer (CT) reaction in terms of the conventional harpooning mechanism. Differentiable functions of PESs are constructed for the reactant and product states that may be applied for 3-dimensional dynamics calculations by means of wavepackets, and examples of 2-dimensional wavepacket dynamics calculations are introduced. Further, electron transfer processes and local electronic nature in the CT reaction are discussed in terms of the quantum mechanical energy densities based on regional density functional theory. Regional partitioning by using the kinetic energy density provides a new concept of electron transfer, and the tension density provides new images of microscopic electronic stresses.     

A new method for side-chain conformation prediction using a Hopfield network and reproduced rotamers

We present a new side-chain prediction method based on energy minimization using a Hopfield network, focusing on the buried residues of proteins. In this method, the network is composed of automata assigned to each rotamer to restrict side-chain conformational space. We reproduced a rotamer library that enabled us to more widely cover the space for side-chain conformations than those previously produced. The accuracy of the side-chain modeling was estimated by three standards: root mean square deviations (rmsds) between the modeled and the crystal structures, the percentages of correctly predicted side-chain torsion angles, and the percentages of correctly predicted hydrogen bonds. The average rmsd for buried side chains of 21 proteins was 1.10 Å. The value was almost always improved relative to the previous works. The percentage of side-chain X₁ angles for buried residues was 87.3%. By considering the hydrogen bond energy, the average percentage of correctly predicted hydrogen bonds rose from 33% without hydrogen bond energy to 52% with the bond energy. We applied this method to homology modeling, where the protein backbone used to predict side-chain conformations deviates from the correct conformation, and could predict side-chain conformations as correctly as those using the correct backbones. © 1996 by John Wiley & Sons, Inc.     

A Paradox of Economic Growth and Relative Deprivation

Rapid economic growth sometimes intensifies people's frustration. In this article, we attempt to formulate this kind of paradox of economic growth, and to explain theoretically how economic growth increases people's dissatisfaction by way of the notion of relative deprivation by employing the theoretical framework of Yitzhaki's relative deprivation index. We introduce the problem of the China puzzle as the latest case of the paradox. Then, we introduce the definition of Yitzhaki's index of relative deprivation, and use this to explain the China puzzle. Besides, through a theoretical examination of Yitzhaki's index, we propose a proposition proving that an increase of relative deprivation in the society can occur even when the amount of wealth increases and the degree of inequality reduces.     

Observation and reaction control of a singlet born radical pair formed photochemically in an SDS micelle by pulsed microwave irradiation

The photochemical reaction of tetraphenylhydrazine in an SDS micellar solution is studied using a transient absorption detected magnetic resonance (ADMR) method. This system is photo-dissociated via the singlet excited state and forms a transient radical pair. Strong microwave irradiation of this system under an × band EPR magnetic field provides an ADMR spectrum of the singlet born radical pair as the optical absorbance change of the diphenylaminyl radical. The employment of a short duration microwave pulse that efficiently flips the electron spin quantum (Δm _s = 1) controls the reaction of the radical pair, and the reaction rate constant of this system is determined. Furthermore, changing the microwave duration shows the quantum beat of this system induced by the electromagnetic field. This beat signal carries both a single beat that corresponds to the Rabi frequency and a double-frequency beat that is due to simultaneous two-spin controlling.     

Comparison between quantitative and subjective assessments of chemotherapy-induced peripheral neuropathy in cancer patients: A prospective cohort study

Objective: Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse event experienced by cancer patients. In general, CIPN is evaluated subjectively based on patient self-assessment or clinician-reported scales; evidence supporting the utility and validity of quantitative sensory tests (QST) is lacking in this patient population. The aim of this study was to objectively assess CIPN of lower extremities by QSTs, and to evaluate the concordance between QSTs and subjective assessments. Methods: In this prospective cohort study, outpatients with cancer receiving chemotherapy were recruited at a single university hospital. We assessed CIPN at the lower extremities at baseline and three months after baseline. The QSTs were performed by applying a monofilament and a tuning fork to determine touch and vibration thresholds, respectively, at the affected site. Subjective assessments were performed based on the visual analog scale (VAS) and the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) toxicity grade. Kappa coefficients were calculated to evaluate the concordance between QSTs and subjective assessments. Results: After exclusion and drop-outs during follow-up, nineteen patients were included in the analysis. The prevalence of patients with abnormal sensation was 37% based on QSTs, 32% based on the VAS, and 14% based on CTCAE grading, respectively. Kappa coefficients were 0.32 between QSTs and VAS, and 0.28 between QSTs and CTCAE. Conclusions: The concordance rates between quantitative and subjective assessments were low. CIPN should be assessed using both quantitative and subjective assessments.     

High resolution off-magic-angle spinning NMR for cholesteric liquid crystals

High resolution NMR of cholesteric liquid crystals is realized by off-magic-angle spinning (OMAS). Using the average potential theory, it is shown that the pitch axes of a cholesteric liquid crystal with a positive (negative) magnetic susceptibility anisotropy are aligned along the spinning axis with an OMAS angle larger (smaller) than the magic angle without any distortion of the helical structure, which is untwisted or distorted by the static magnetic field in some static samples. Hence, the line broadening due to the anisotropies of chemical shifts and/or quadrupole couplings is removed, while information of the anisotropies in cholesteric alignments can be obtained from the line positions. A detailed theoretical analysis of effects of spinning frequency and molecular diffusion along the pitch axis on the linewidth is given, predicting that the resolution is improved greatly at a spinning frequency much higher than the rotational diffusion coefficient. These theoretical results are verified by ¹³C OMAS experiments on a cholesteric liquid crystal of p-ethoxybenzyl-p-[(S)-2- methylbutyl]aniline (EBMBA) and cholesteric mixtures of p-methoxybenzylidene-p-n-butylaniline (MBBA) and cholesteryl chloride (CC).