2,691 research outputs found

    Hawking Radiation of Apparent Horizon in a FRW Universe

    Full text link
    Hawking radiation is an important quantum phenomenon of black hole, which is closely related to the existence of event horizon of black hole. The cosmological event horizon of de Sitter space is also of the Hawking radiation with thermal spectrum. By use of the tunneling approach, we show that there is indeed a Hawking radiation with temperature, T=1/2πr~AT=1/2\pi \tilde r_A, for locally defined apparent horizon of a Friedmann-Robertson-Walker universe with any spatial curvature, where r~A\tilde r_A is the apparent horizon radius. Thus we fill in the gap existing in the literature investigating the relation between the first law of thermodynamics and Friedmann equations, there the apparent horizon is assumed to have such a temperature without any proof. In addition, we stress the implication of the Hawking temperature associated with the apparent horizon.Comment: Latex, 9 paages; v2 published versio

    p38 Mapk signal pathway involved in anti-inflammatory effect of chaihu-shugan-san and shen-ling-bai-zhu-san on hepatocyte in non-alcoholic steatohepatitis rats

    Get PDF
    Background: Traditional Chinese Medicine (TCM), has over thousands-of-years history of use. Chaihu-Shugan-San (CSS), and Shen-ling-bai-zhu-San (SLBZS), are famous traditional Chinese herbal medicine formulas, which have been used in China, for the treatment of many chronic diseases.Materials and Methods:This study investigated the anti-inflammatory effects of CSS and SLBZS on signaling molecules involved in p38 mitogen-activated protein kinase (p38 MAPK), pathway on hepatocytes of non-alcoholic steatohepatitis (NASH), rats induced by high fat diet. SD male rats were randomly divided into 8 groups: negative control group, model control group, high (9.6g/kg/day)/low (3.2g/kg/day)-dose CSS group, high (30g/kg/day)/low (10g/kg/day)-dose SLBZS group, high (39.6g/kg/day)/low (13.2g/kg/day)-dose integrated group. The rats of NASH model were induced by feeding a high-fat diet. After 16, wks, Hepatocytes were isolated from 6, rats in each group by collagenase perfusion. The liver histopathological changes and serum inflammatory cytokines TNF-α, IL-6 were determined. The proteins of TLR4,  phosphor-p38 MAPK and p38 MAPK involved in p38 MAPK signal pathway were assayed.Results: The statistical data indicated the NASH model rats reproduced typical histopathological features of NASH in human. CSS and SLBZS ameliorated lipid metabolic disturbance, attenuated NASH progression, decreased the levels of TNF-α and IL-6 in serum, as well as inhibited TLR4 protein expression, p38 MAPK phosphorylation, and activation of p38 MAPK. In conclusion, CSS and SLBZS might work as a significant anti-inflammatory effect on hepatocyte of NASH by inhibiting the activation of TLR4, p-p38 MAPK and p38 MAPK involved in p38 MAPK signal pathway.Conclusion: To some extent, CSS and SLBZS may be a potential alternative and complementary medicine to protect against liver injury, alleviate the inflammation reaction, moderate NASH progression.Key words: p38 mitogen-activated protein kinase; Toll like receptor 4; Hepatocytes; Non-alcoholic Steatohepatitis; Traditional Chinese medicine

    Merging Brain-Computer Interface P300 speller datasets: Perspectives and pitfalls

    Get PDF
    BackgroundIn the last decades, the P300 Speller paradigm was replicated in many experiments, and collected data were released to the public domain to allow research groups, particularly those in the field of machine learning, to test and improve their algorithms for higher performances of brain-computer interface (BCI) systems. Training data is needed to learn the identification of brain activity. The more training data are available, the better the algorithms will perform. The availability of larger datasets is highly desirable, eventually obtained by merging datasets from different repositories. The main obstacle to such merging is that all public datasets are released in various file formats because no standard way is established to share these data. Additionally, all datasets necessitate reading documents or scientific papers to retrieve relevant information, which prevents automating the processing. In this study, we thus adopted a unique file format to demonstrate the importance of having a standard and to propose which information should be stored and why.MethodsWe described our process to convert a dozen of P300 Speller datasets and reported the main encountered problems while converting them into the same file format. All the datasets are characterized by the same 6 x 6 matrix of alphanumeric symbols (characters and numbers or symbols) and by the same subset of acquired signals (8 EEG sensors at the same recording sites).Results and discussionNearly a million stimuli were converted, relative to about 7000 spelled characters and belonging to 127 subjects. The converted stimuli represent the most extensively available platform for training and testing new algorithms on the specific paradigm - the P300 Speller. The platform could potentially allow exploring transfer learning procedures to reduce or eliminate the time needed for training a classifier to improve the performance and accuracy of such BCI systems

    Isometric contraction of skeletal muscle with multiple parameters

    Get PDF
    2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    The measurement of skeletal muscle with multi-parameters by sonography

    Get PDF
    2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Evidence Base of Clinical Studies on Qi Gong: A Bibliometric Analysis

    Get PDF
    © 2020 The Authors Objective: This bibliometric study aimed to systematically and comprehensively summarize the volume, breadth and evidence for clinical research on Qigong. And this bibliometric analysis also can provide the evidence of this field. Design: Bibliometric analysis. Methods: All types of primary and secondary studies on humans were included: systematic reviews, randomized clinical trials, non-randomized controlled clinical studies, case series and case reports. Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Chinese Scientific Journal Database, Chinese Academic Conference Papers Database and Chinese Dissertation Database, PubMed and the Cochrane Library were searched from the date of inception to December 10, 2018. Bibliometric information, such as publication information, disease/condition, Qigong intervention and research results were extracted and analyzed. Results: A total of 886 clinical studies were identified: including 47 systematic reviews, 705 randomized clinical trials, 116 non-randomized controlled clinical studies, 12 case series and 6 case reports. The studies were conducted in 14 countries. The top 15 diseases/conditions studied were: diabetes, chronic obstructive pulmonary disease, hypertension, stroke, cervical spondylosis, lumbar disc herniation, insomnia, knee osteoarthritis, low back pain, and osteoporosis, Coronary heart disease, breast cancer, periarthritis of shoulder, depression, metabolic syndrome. Of the various Qigong exercises reported in these 886 clinical studies, Ba Duan Jin was the most frequently researched in 492 (55.5%) studies, followed by Health Qigong 107 (12.1%), Dao Yin Shu 85 (9.6%), Wu Qin Xi 67 (7.6%) and Yi Jin Jing 66 (7.4%). The most frequently used comparisons in randomized trials were maintaining normal way of life unchanged 149 (18.1%), the remaining controls included conventional treatment, mainly western medicine, Chinese herbal medicine, acupuncture, health education, psychological therapy, Yoga, Tai Chi and other non-drug therapy. The most frequently reported outcomes were physical function, quality of life, symptoms, pain and mental health indicators. Beneficial results from practicing Qigong were reported in 97% of studies. Conclusions: Qigong research publications have been increasing gradually. Reports on study types, participants, Qigong Intervention, and outcomes are diverse and inconsistent. There is an urgent need to develop a set of reporting standards for various interventions of Qigong. Further trials of high methodological quality with sufficient sample size and real world studies are needed to verify the effects of Qigong in health and disease management

    Study of the transient and depth-dependent swelling behavior of articular cartilage by ultrasound

    Get PDF
    2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    EFFECT OF STRUCTURAL RELAXATION ON THE DEFORMATION BEHAVIOR OF A Zr64.13Cu15.75Ni10.12Al10 BULK METALLIC GLASS UNDER NANOINDENTATION

    Get PDF
    Structural relaxation by isothermal annealing below the glass transition temperature is conducted on a Zr64.13Cu15.75Ni10.12Al10 bulk metallic glass. The effect of structural relaxation on thermal and mechanical properties was investigated by differential scanning calorimetry and instrumented nanoindentation. The recovery of the enthalpy in the DSC curves indicates that thermally unstable defects were annihilated through structural relaxation. During nanoindentation, the structural relaxation did not have a significant influence on the serrated plastic flow behavior. However, Structural relaxation shows an obvious effect in increasing both the hardness and elastic modulus, which is attributed to the annihilation of thermally unstable defects that resulted from the relaxation

    Realizing and characterizing chiral photon flow in a circuit quantum electrodynamics necklace

    Get PDF
    Gauge theory plays the central role in modern physics. Here we propose a scheme of implementing artificial Abelian gauge fields via the parametric conversion method in a necklace of superconducting transmission line resonators (TLRs) coupled by superconducting quantum interference devices (SQUIDs). The motivation is to synthesize an extremely strong effective magnetic field for charge-neutral bosons which can hardly be achieved in conventional solid-state systems. The dynamic modulations of the SQUIDs can induce effective magnetic fields for the microwave photons in the TLR necklace through the generation of the nontrivial hopping phases of the photon hopping between neighboring TLRs. To demonstrate the synthetic magnetic field, we study the realization and detection of the chiral photon flow dynamics in this architecture under the influence of decoherence. Taking the advantages of its simplicity and flexibility, this parametric scheme is feasible with state-of-the-art technology and may pave an alternative way for investigating the gauge theories with superconducting quantum circuits. We further propose a quantitative measure for the chiral property of the photon flow. Beyond the level of qualitative description, the dependence of the chiral flow on external pumping parameters and cavity decay is characterized

    A preliminary study on evaluation of muscle fatigue with B-mode ultrasound

    Get PDF
    2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
    corecore