A Physical Measure for Characterizing Crossover from Integrable to Chaotic Quantum Systems.

In this paper, a quantity that describes a response of a system's eigenstates to a very small perturbation of physical relevance is studied as a measure for characterizing crossover from integrable to chaotic quantum systems. It is computed from the distribution of very small, rescaled components of perturbed eigenfunctions on the unperturbed basis. Physically, it gives a relative measure to prohibition of level transitions induced by the perturbation. Making use of this measure, numerical simulations in the so-called Lipkin-Meshkov-Glick model show in a clear way that the whole integrability-chaos transition region is divided into three subregions: a nearly integrable regime, a nearly chaotic regime, and a crossover regime.

Identifying risk factors for chronic kidney disease stage 3 in adults with acquired solitary kidney from unilateral nephrectomy: a retrospective cohort study.

BACKGROUND: We aimed to examine the risk factors for chronic kidney disease (CKD) stage 3 among adults with ASK from unilateral nephrectomy. METHODS: We retrospectively collected data from adult patients with ASK between January, 2009 and January, 2019, identified from a tertiary hospital in China. The clinical data were compared between patients who developed CKD stage 3 and those who did not develop CKD stage 3 during follow-up. RESULTS: In total, 172 patients with ASK (110 men; median 58.0 years) were enrolled, with a median follow-up duration of 5.0 years. During follow-up, 91 (52.9%) and 24 (14.0%) patients developed CKD stage 3 and end-stage renal disease, respectively. Multiple regression analyses showed that age (odds ratio [OR] 1.076, 95% confidence interval [CI] 1.039-1.115, p < 0.001), diabetes (OR 4.401, 95% CI 1.693-11.44, p = 0.002), hyperuricemia (OR 2.733, 95% CI 1.104-6.764, p = 0.03), a history of cardiovascular disease (CVD) (OR 5.583, 95% CI 1.884-18.068, p = 0.002), and ASK due to renal tuberculosis (OR 8.816, 95% CI 2.92-26.62, p < 0.001) were independent risk factors for developing CKD stage 3 among patients with ASK. CONCLUSIONS: Regular follow-up of renal function is needed among adult patients with ASK. Optimal management of diabetes, hyperuricemia, and CVD may reduce their risk of CKD stage 3, especially among those that undergo unilateral nephrectomy for renal tuberculosis.

SF36 Is a Reliable Patient-Oriented Outcome Evaluation Tool in Surgically Treated Degenerative Cervical Myelopathy Cases: A Systematic Review and Meta-Analysis.

BACKGROUND Degenerative spinal disorders have adverse impacts on patients' quality of life. Because the main objectives of any surgical intervention are to improve health-related quality of life and to reduce disability, instruments capable of measuring patient-oriented outcomes are now increasingly used. The aim of this study was to evaluate the use of the Short Form 36 Health Survey Questionnaire (SF36) for assessing patient-oriented outcomes of degenerative cervical myelopathy surgery. MATERIAL AND METHODS A literature search was conducted in electronic databases (Google Scholar, Ovid SP, PubMed, Science Direct, and Springer). Studies were included if they reported SF36 scores by following patients for at least 12 months. Random effects meta-analyses were performed to estimate changes in SF36 physical/mental component summary (SF36-PCS/MCS), SF36 dimensional, Japanese Orthopedics Association (JOA)/modified JOA (mJOA), and Neck Disability Index (NDI) scores by latest follow-up. RESULTS Fourteen studies (1966 patients; age 58.2 years [95% confidence interval (CI), 56.6 to 59.9]; 60% males [95% CI, 55 to 64]; follow-up 24.8 months [95% CI, 20.9 to 28.7]) were included in meta-analysis. SF36-PCS (6.60 [95% CI, 4.91 to 8.28]; p<0.00001), SF36-MCS (6.33 [95% CI, 4.31 to 8.35]; p<0.00001) and SF36 dimensional (p<0.05) scores improved significantly at latest follow-up. Surgery significantly improved JOA/mJOA (3.43 [95% CI, 2.80 to 4.06]; p<0.00001) and NDI (-13.70 [95% CI, -17.35 to -10.06]; p<0.00001) scores also. Change in SF36-PCS score were correlated (r=-0.554) with change in NDI score, whereas change in SF36-MCS score was correlated with change in JOA score (r=0.550). CONCLUSIONS Surgery for degenerative cervical myelopathy is associated with significantly improved SF36-measured patient-oriented outcomes.

[Correlation Study on Pathological Characteristics of Target Organs and Excess Evil Syndrome in IgA Nephropathy].

OBJECTIVE: To explore the correlation between pathological characteristics of target organs and excess evil syndrome in IgA nephropathy. METHODS: Data were collected in multicenter cooperation. Totally 266 IgA nephropathy patients were typed into exogenous wind-heat affection syndrome (49 cases), lower energizer damp-heat syndrome (100 cases), damp-phlegm syndrome (43 cases), and blood stasis syndrome (74 cases). Meanwhile, percutaneous renal biopsy was performed in all patients for Hass classification, Oxford classification, Katafuchi integral, and Jiang's classification methods. The correlation between excess evil syndrome and pathological index was analyzed. RESULTS: Four syndrome types were correlated with their Hass levels (r = 0. 341, P <0. 01). Affection of exogenous wind-heat syndrome was correlated with segmental proliferation of endothelial cells and damaged active lesions of segmental capillary loops. Lower-energizer damp-heat syndrome was associated with Hass III level, destroying active lesions of capillary loops, segmental proliferation of endothelial cells, glomerular segmental lesions, focal interstitial infiltration of inflammatory cells, focal interstitial fibrosis and tubular atrophy. Blood stasis syndrome was associated with Hass IV level, glomerular sclerosis, segmental glomerulosclerosis (S)/adhesion, mesangial hypercellularity (M), angiohyalinosis, multi-foci interstitial infiltration of inflammatory cells, multi-foci interstitial fibrosis and tubular atrophy. Phlegm-damp syndrome had higher proportions of Hass I and III levels, but with no association with other pathological parameters. CONCLUSIONS: Excess evil syndrome was associated with partial pathological characteristics of IgA nephropathy. It could reflect pathological damage degree of target organs, activities, chronic lesions, and prognosis of IgA nephropathy to certain extent. Correlated pathological characteristics and its evolution could indicate excess evil syndrome types and their evolution rules.

Preferred states of decoherence under intermediate system-environment coupling.

The notion that decoherence rapidly reduces a superposition state to an incoherent mixture implicitly adopts a special representation, namely, the representation of preferred (pointer) states (PS). For weak or strong system-envrionment interaction, the behavior of PS is well known. Via a simple dynamical model that simulates a two-level system interacting with few other degrees of freedom as its environment, it is shown that even for intermediate system-environment coupling, approximate PS may still emerge from the coherent quantum dynamics of the whole system in the absence of any thermal averaging. The found PS can also continuously deform to expected limits for weak or strong system-environment coupling. Computational results are also qualitatively explained. The findings should be useful towards further understanding of decoherence and quantum thermalization processes.

T-2 toxin induces degenerative articular changes in rodents: link to Kaschin-Beck disease.

Osteoarthritis (OA) is a degenerative joint disease that is characterized by joint pain and a progressive loss of articular cartilage. Kaschin-Beck Disease is a form of endemic OA in China whose etiology is unclear, but epidemiological data indicate a possible link to trichothecenes mycotoxin exposure. In vitro, T-2 toxin, a trichothecenes mycotoxin, has been demonstrated to inhibit aggrecan synthesis and promote aggrecanase and pro-inflammatory cytokine production in cultured chondrocytes. To assess the effects of T-2 toxin on articular cartilage in vivo, Wistar rats were fed a diet containing T-2 toxin (100 ng/kg chow) for six and ten months. Following six months of T-2 toxin exposure, histopathological changes in femorotibial cartilage were characterized by chondrocyte degeneration/necrosis and loss, chondrocyte clones, and loss of proteoglycan staining of articular cartilage, sometimes involving the entire thickness of the cartilage in the tibial plateaus and femoral condyles. By ten months, in addition to these changes, there was evidence of cartilage fibration in some rats. In conclusion, T-2 toxin exposure in rats induced degenerative lesions in articular cartilage similar to spontaneous OA, lending support to an etiologic role of mycotoxins in Kaschin-Beck Disease. T-2 toxin-induced degenerative joint disease may be a useful model of metabolic polyarticular OA.

Quantum chaos and the correspondence principle.

The correspondence principle is a cornerstone in the entire construction of quantum mechanics. This principle has been recently challenged by the observation of an early-time exponential increase of the out-of-time-ordered correlator (OTOC) in classically nonchaotic systems [E. B. Rozenbaum et al., Phys. Rev. Lett. 125, 014101 (2020)PRLTAO0031-900710.1103/PhysRevLett.125.014101]. Here, we show that the correspondence principle is restored after a proper treatment of the singular points. Furthermore, our results show that the OTOC maintains its role as a diagnostic of chaotic dynamics.

Closeness of the reduced density matrix of an interacting small system to the Gibbs state.

I study the statistical description of a small quantum system, which is coupled to a large quantum environment in a generic form and with a generic interaction strength, when the total system lies in an equilibrium state described by a microcanonical ensemble. The focus is on the difference between the reduced density matrix (RDM) of the central system in this interacting case and the RDM obtained in the uncoupled case. In the eigenbasis of the central system's Hamiltonian, it is shown that the difference between diagonal elements is mainly confined by the ratio of the maximum width of the eigenfunctions of the total system in the uncoupled basis to the width of the microcanonical energy shell; meanwhile, the difference between off-diagonal elements is given by the ratio of certain property of the interaction Hamiltonian to the related level spacing of the central system. As an application, a sufficient condition is given, under which the RDM may have a canonical Gibbs form under system-environment interactions that are not necessarily weak; this Gibbs state usually includes certain averaged effect of the interaction. For central systems that interact locally with many-body quantum chaotic systems, it is shown that the RDM usually has a Gibbs form. I also study the RDM which is computed from a typical state of the total system within an energy shell.

Decay of Loschmidt echo in a Bose-Einstein condensate at a dynamical phase transition.

We study the quantum Loschmidt echo (LE) in a Bose-Einstein condensate (BEC) in a double-well potential. The BEC may undergo a dynamical phase transition between two phases: a tunneling phase and a self-trapping phase. For sufficiently weak perturbation, the LE has Gaussian decay in both phases. While, for relatively strong perturbation, the LE has a Gaussian decay in the self-trapping phase and has a stretched exponential decay in the tunneling phase. This qualitative difference in the decaying law of the LE in the two phases provides a characterization of the dynamical phase transition of the BEC. The semiclassical theory is used to explain the numerically observed behaviors of the LE decay.

Sensitivity of quantum motion to perturbation in a triangle map.

We study quantum Loschmidt echo, or fidelity, in the triangle map whose classical counterpart has linear instability and weak chaos. Numerically, three regimes of fidelity decay have been found with respect to the perturbation strength epsilon. In the regime of weak perturbation, the fidelity decays as exp(-c epsilon(2)t(gamma)) with gamma approximately 1.7. In the regime of strong perturbation, the fidelity is approximately a function of epsilont(2.5), which is predicted for the classical fidelity [G. Casati, Phys. Rev. Lett. 94, 114101 (2005)], and decays slower than power-law decay for long times. In an intermediate regime, the fidelity has approximately an exponential decay exp(-c' epsilont).

Stability of Fock states in a two-component Bose-Einstein condensate with a regular classical counterpart.

We study the stability of a two-component Bose-Einstein condensate (BEC) in the parameter regime in which its classical counterpart has regular motion. The stability is characterized by the fidelity for both the same and different initial states. We study as initial states the Fock states with definite numbers of atoms in each component of the BEC. It is found that for some initial times the two Fock states with all the atoms in the same component of the BEC are more stable than Fock states with atoms distributed in the two components. An experimental scheme is discussed, in which the fidelity can be measured in a direct way.

Decoherence approach to energy transfer and work done by slowly driven systems.

A main problem, which is met when computing the energy transfer of or work done by a quantum system, comes from the fact that the system may lie in states with coherence in its energy eigenstates. As is well known, when the so-called environment-induced decoherence has happened with respect to a preferred basis given by the energy basis, no coherence exists among the energy basis and the energy change of the system can be computed in a definite way. I argue that one may make use of this property, in the search for an appropriate definition of quantum work for a total system that does not include any measuring apparatus. To show how this idea may work, in this paper, I study decoherence properties of a generic slowly driven system, which is weakly coupled to a huge environment whose main body is a complex quantum system. It is shown that decoherence may generically happen for such a system.

Characterization of random features of chaotic eigenfunctions in unperturbed basis.

In this paper we study random features manifested in components of energy eigenfunctions of quantum chaotic systems, given in the basis of unperturbed, integrable systems. Based on semiclassical analysis, particularly on Berry's conjecture, it is shown that the components in classically allowed regions can be regarded as Gaussian random numbers in a certain sense, when appropriately rescaled with respect to the average shape of the eigenfunctions. This suggests that when a perturbed system changes from integrable to chaotic, deviation of the distribution of rescaled components in classically allowed regions from the Gaussian distribution may be employed as a measure for the "distance" to quantum chaos. Numerical simulations performed in the Lipkin-Meshkov-Glick model and the Dicke model show that this deviation coincides with the deviation of the nearest-level-spacing distribution from the prediction of random-matrix theory. Similar numerical results are also obtained in two models without classical counterpart.

Fourier heat conduction as a strong kinetic effect in one-dimensional hard-core gases.

For a one-dimensional (1D) momentum conserving system, intensive studies have shown that generally its heat current autocorrelation function (HCAF) tends to decay in a power-law manner and results in the breakdown of the Fourier heat conduction law in the thermodynamic limit. This has been recognized to be a dominant hydrodynamic effect. Here we show that, instead, the kinetic effect can be dominant in some cases and leads to the Fourier law for finite-size systems. Usually the HCAF undergoes a fast decaying kinetic stage followed by a long slowly decaying hydrodynamic tail. In a finite range of the system size, we find that whether the system follows the Fourier law depends on whether the kinetic stage dominates. Our Rapid Communication is illustrated by the 1D hard-core gas models with which the HCAF is derived analytically and verified numerically by molecular dynamics simulations.

Stability of quantum motion in regular systems: a uniform semiclassical approach.

We study the stability of quantum motion of classically regular systems in the presence of small perturbations. On the basis of a uniform semiclassical theory we derive the fidelity decay which displays a quite complex behavior, from Gaussian to power law decay t(-alpha), with 1

Internal temperature of quantum chaotic systems at the nanoscale.

The extent to which a temperature can be appropriately assigned to a small quantum system, as an internal property but not as a property of any large environment, is still an open problem. In this paper, a method is proposed for solving this problem, by which a studied small system is coupled to a two-level system as a probe, the latter of which can be measured by measurement devices. A main difficulty in the determination of possible temperature of the studied system comes from the back-action of the probe-system coupling to the system. For small quantum chaotic systems, we show that a temperature can be determined, the value of which is sensitive to neither the form, location, and strength of the probe-system coupling, nor the Hamiltonian and initial state of the probe. The temperature thus obtained turns out to have the form of Boltzmann temperature.

Correlations in eigenfunctions of quantum chaotic systems with sparse Hamiltonian matrices.

In most realistic models for quantum chaotic systems, the Hamiltonian matrices in unperturbed bases have a sparse structure. We study correlations in eigenfunctions of such systems and derive explicit expressions for some of the correlation functions with respect to energy. The analytical results are tested in several models by numerical simulations. Some applications are discussed for a relation between transition probabilities and for expectation values of some local observables.

Uniform semiclassical approach to fidelity decay: from weak to strong perturbation.

We study fidelity decay by a uniform semiclassical approach, in the three perturbation regimes: namely, the perturbative regime, the Fermi golden rule (FGR) regime, and the Lyapunov regime. A semiclassical expression is derived for the fidelity of initial Gaussian wave packets with width of the order sqare root h (h being the effective Planck constant). The short-time decay of the fidelity of initial Gaussian wave packets is also studied with respect to two time scales introduced in the semiclassical approach. In the perturbative regime, it is confirmed numerically that fidelity has FGR-type decay before Gaussian decay sets in. An explanation is suggested for a non-FGR decay in the FGR regime of a system with weak chaos in the classical limit by using the Levy distribution as an approximation for the distribution of the action difference. In the Lyapunov regime, it is shown that the average of the logarithm of fidelity may have roughly Lyapunov decay within some time interval in systems possessing large fluctuations in the finite-time Lyapunov exponent in the classical limit.

Uniform semiclassical approach to fidelity decay in the deep Lyapunov regime.

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.

[Effect of qingfei oral liquid on protein expression of transforming growth factor-beta1 and platelet derived growth factor-BB of adenovirus type 3I, 7b induced human embryonic lung fibroblast cells].

OBJECTIVE: To explore the effect of qingfei oral liquid (QOL) contained serum on protein expression of transforming growth factor-beta1 (TGF-beta1) and platelet derived growth factor-BB (PDGF-BB) of adenovirus type 3I, 7b induced human embryonic lung fibroblast cells. METHODS: The cells were divided into 5 groups, the normal cells group (NCG), the virus control group (VCG), the blank serum group (BSG), the ribavirin group (RVG) and the QOL contained serum group (QSG). All the cells except those in the NCG were challenged by adenovirus type 3I, 7b and treated with correspondent medicine. The contents of TGF-beta1 and PDGF-BB in the supernatant of cell culture were monitored by ELISA and compared among groups. RESULTS: Contents of TGF-beta1 and PDGF-BB in VCG were significantly higher, while those in QSG were significantly lower than those in VCG (P < 0.01). CONCLUSION: Adenovirus infection can increase the protein expression of TGF-beta1 and PDGF-BB of human embryonic lung fibroblast cells. QOL can decrease the protein expression of these cytokines, which maybe one of the mechanisms of its antiviral effect.