Biomedical subjects
Publications and source records attributed to Wen-ge Wang.
We use the uniform semiclassical approximation in order to derive the fidelity decay in the regime of large perturbations. Numerical computations are presented which agree with our theoretical predictions. Moreover, our theory allows us to explain previous findings, such as the deviation from the Lyapunov decay rate in cases where the classical finite-time instability is nonuniform in phase space.
OBJECTIVE: To observe the effect of verapamil-procaine compound (V-P) on prevention and treatment of acute respiratory distress syndrome (ARDS) subsequent to high risk operation. METHODS: Altogether 150 cases of major operations with high risk of ARDS were enrolled for study. They were randomly divided into three groups. V-P group: 5% glucose 500 ml and procaine 1 250 mg and verapamil 10 mg; procaine group: 5% glucose 500 ml and procaine 1 250 mg; control group: only glucose was given. The injection speed of the three groups were the same, and it was kept at 0.5 ml x h(-1) x kg(-1). The dosages of verapamil and procaine in V-P group and procaine group were doubled when the diagnosis of acute lung injury (ALI) or ARDS was confirmed. UT4000F was used in monitoring (non-invasive) blood pressure (BP), electrocardiogram (ECG), pulse oxygen saturation (SpO(2)), respiratory rate, and temperature. Blood routine and arterial blood gases measurements were intermittently performed. Diagnosis of systemic inflammatory response syndrome (SIRS), ALI and ARDS was made respectively according to published diagnostic criteria. SIRS score and acute physiology and chronic health evaluation II (APACHEII) score were performed. RESULTS: Eleven cases in V-P group, 26 in procaine group, and 42 in control group manifested symptoms and signs of SIRS. There were notable differences among groups (all P<0.01). Four patients in V-P group, 7 in procaine group, and 19 in control group were shown to develop ALI. Significant difference was found between control and V-P or procaine group (both P<0.01), but no significant difference was found between procaine group and V-P group. Twelve cases were complicated with ARDS in control group 2 weeks after the operation, and among them 5 died of multiple organ failure. There was significant difference between control group and V-P group or procaine group (both P<0.01). Two patients were complicated with acute renal failure in V-P group, 2 in procaine group, and 5 in control group. CONCLUSION: The V-P can interrupt SIRS to develop ALI, then ARDS and multiple organ dysfunction syndrome(MODS), and thus prevents and cures ARDS.
We study, analytically and numerically, the stability of quantum motion for a classically chaotic system. We show the existence of different regimes of fidelity decay. In particular, when the underlying classical dynamics is weakly chaotic, deviations from Fermi-golden-rule and Lyapounov regimes are observed and discussed.
It is shown that localization of eigenfunctions in the Wigner band random matrix model with increasing diagonal elements can be related to localization in a band random matrix model with random diagonal elements. The relation is obtained by making use of a result of a generalization of Brillouin-Wigner perturbation theory, which shows that reduced Hamiltonian matrices with relatively small dimensions can be introduced for nonperturbative parts of eigenfunctions, and by employing intermediate basis states, which can improve the method of the reduced Hamiltonian matrix. The latter model deviates from the standard band random matrix model mainly in two aspects: (i) the root mean square of diagonal elements is larger than that of off-diagonal elements within the band, and (ii) statistical distributions of the matrix elements are close to the Lévy distribution in their central parts, except in the high top regions.
We study the division of components of energy eigenfunctions, as the expansion of perturbed states in unperturbed states, into nonperturbative and perturbative parts in a three-orbital schematic shell model possessing a chaotic classical limit, the Hamiltonian of which is composed of a Hamiltonian of noninteracting particles and a perturbation. The perturbative parts of eigenfunctions are expanded in a convergent perturbation expansion by making use of the nonperturbative parts. The division is shown to have the property that, when the underlying classical system is chaotic, the statistics of the components of the nonperturbative parts whose relative localization length are close to 1 is in agreement with the prediction of random-matrix theory. When the underlying classical system is mixed, main bodies of most of the eigenfunctions are found to occupy parts of their nonperturbative regions, with some of the rest of the eigenfunctions being "ergodic" in their nonperturbative regions due to avoided level crossings. In case of the classical system being chaotic, most of the eigenfunctions are found "ergodic" or almost "ergodic" in their nonperturbative regions. Numerical results show that the average relative localization length of nonperturbative parts of eigenfunctions is useful in characterizing the behavior of the quantum system in the process of the underlying classical system changing from a mixed system to a chaotic one.
Explore the source record for details and available documents.
Explore the source record for details and available documents.