1,825 research outputs found

    Spin transfer and polarization of antihyperons in lepton induced reactions

    Full text link
    We study the polarization of antihyperon in lepton induced reactions such as e+eHˉ+Xe^+e^-\to\bar H+X and l+pl+Hˉ+Xl+p\to l'+\bar H+X with polarized beams using different models for spin transfer in high energy fragmentation processes. We compare the results with the available data and those for hyperons. We make predictions for future experiments.Comment: 31 pages, 6 figures. submitted to Phys. Rev. D. content changed, references adde

    Constraints on Ho\v{r}ava-Lifshitz gravity from GRB 170817A

    Full text link
    In this work we focus on a toy model: (3+1)-dimensional Ho\v{r}ava-Lifshitz gravity coupling with an anisotropic electromagnetic (EM) field which is generated through a Kaluza-Klein reduction of a (4+1)-dimensional Ho\v{r}ava-Lifshitz gravity. This model exhibits a remarkable feature that it has the same velocity for both gravitational and electromagnetic waves. This feature makes it possible to restrict the parameters of the theory from GRB 170817A. In this work we use this feature to discuss possible constraints on the parameter β\beta in the theory, by analyzing the possible Lorentz invariance violation effect of the GRB 170817A. This is achieved by analyzing potential time delay of gamma-ray photons in this event. It turns out that it places a stringent constraint on this parameter. In the most ideal case, it gives 1β<(10191018)|1-\sqrt{\beta}|<(10^{-19}-10^{-18}).Comment: 21 pages, 2 tables. Accepted for publication in EPJ

    Barrier Inhomogeneity of Schottky Diode on Nonpolar AlN Grown by Physical Vapor Transport

    Full text link
    An aluminum nitride (AlN) Schottky barrier diode (SBD) was fabricated on a nonpolar AlN crystal grown on tungsten substrate by physical vapor transport. The Ni/Au-AlN SBD features a low ideality factor n of 3.3 and an effective Schottky barrier height (SBH) of 1.05 eV at room temperature. The ideality factor n decreases and the effective SBH increases at high temperatures. The temperature dependences of n and SBH were explained using an inhomogeneous model. A mean SBH of 2.105 eV was obtained for the Ni-AlN Schottky junction from the inhomogeneity analysis of the current-voltage characteristics. An equation in which the parameters have explicit physical meanings in thermionic emission theory is proposed to describe the current-voltage characteristics of inhomogeneous SBDs.Comment: 6 pages, 6 figure

    Research progress on antidepressant effects and mechanisms of berberine

    Get PDF
    Depression, a global health problem with growing prevalence, brings serious impacts on the daily life of patients. However, the antidepressants currently used in clinical are not perfectly effective, which greatly reduces the compliance of patients. Berberine is a natural quaternary alkaloid which has been shown to have a variety of pharmacological effects, such as hypoglycemic, lipid-regulation, anti-cancer, antibacterial, anti-oxidation, anti-inflammatory, and antidepressant. This review summarizes the evidence of pharmacological applications of berberine in treating depression and elucidates the mechanisms of berberine regulating neurotransmitter levels, promoting the regeneration of hippocampal neurons, improving hypothalamic-pituitary-adrenal axis dysfunction, anti-oxidative stress, and suppressing inflammatory status in order to provide a reference for further research and clinical application of berberine

    Prevalence of Clonorchis sinensis infection in dogs and cats in subtropical southern China

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Clonorchiasis, caused by <it>Clonorchis sinensis</it>, is one of the major parasitic zoonoses in China, particularly in China's southern Guangdong province where the prevalence of <it>C. sinensis </it>infection in humans is high. However, little is known of the prevalence of <it>C. sinensis </it>infection in its reservoir hosts dogs and cats. Hence, the prevalence of <it>C. sinensis </it>infection in dogs and cats was investigated in Guangdong province, China between October 2006 and March 2008.</p> <p>Results</p> <p>A total of 503 dogs and 194 cats from 13 administrative regions in Guangdong province were examined by post-mortem examination. The worms were examined, counted, and identified to species according to existing keys and descriptions. The average prevalences of <it>C. sinensis </it>infection in dogs and cats were 20.5% and 41.8%, respectively. The infection intensities in dogs were usually light, but in cats the infection intensities were more serious. The prevalences were higher in some of the cities located in the Pearl River Delta region which is the most important endemic area in Guangdong province, but the prevalences were relatively lower in seaside cities.</p> <p>Conclusions</p> <p>The present investigation revealed a high prevalence of <it>C. sinensis </it>infection in its reservoir hosts dogs and cats in China's subtropical Guangdong province, which provides relevant "base-line" data for conducting control strategies and measures against clonorchiasis in this region.</p

    Earthquake-related pelvic crush fracture vs. non-earthquake fracture on digital radiography and MDCT: a comparative study

    Get PDF
    OBJECTIVE: To determine the features of earthquake-related pelvic crush fractures versus non-earthquake fractures with digital radiography and multidetector row computed tomography. METHODS: One hundred and sixty-seven survivors with pelvic crush fractures in the 2008 Sichuan earthquake were entered in our study as the earthquake-related group (139 underwent digital radiography, 28 underwent multidetector row computed tomography); 70 victims with non-earthquake pelvic fractures were enrolled into this study as the non-earthquake group (54 underwent digital radiography, 16 underwent multidetector row computed tomography). Data were reviewed retrospectively between groups, focusing on anatomic distributions, status of pelvic bone fractures, numbers of pelvic bones involved, and classification of pelvic ring fractures according to the Tile classification system. RESULTS: Pelvic fractures occurred more frequently in the pubis in the earthquake-related group than in the non-earthquake group (135/167, 81% vs. 48/70, 69%). In addition, comminuted fractures were more common in the earthquake-related group than in the non-earthquake group (55/167, 33% vs. 10/70, 14%). Multiple fractures were less common in the earthquake-related group than in the non-earthquake group (81/167, 49% vs. 46/70, 66%). Regarding the classification of pelvic ring fractures, Type C predominantly composed of subtype C3 occurred more frequently (64/167, 38% vs. 12/70, 17%), and Type A was less common in the earthquake-related group than in the non-earthquake group (31/167, 19% vs. 23/70, 32%). All differences were statistically significant (

    Earthquake-related pelvic crush fracture vs. non-earthquake fracture on digital radiography and MDCT: a comparative study

    Get PDF
    OBJECTIVE: To determine the features of earthquake-related pelvic crush fractures versus non-earthquake fractures with digital radiography and multidetector row computed tomography. METHODS: One hundred and sixty-seven survivors with pelvic crush fractures in the 2008 Sichuan earthquake were entered in our study as the earthquake-related group (139 underwent digital radiography, 28 underwent multidetector row computed tomography); 70 victims with non-earthquake pelvic fractures were enrolled into this study as the non-earthquake group (54 underwent digital radiography, 16 underwent multidetector row computed tomography). Data were reviewed retrospectively between groups, focusing on anatomic distributions, status of pelvic bone fractures, numbers of pelvic bones involved, and classification of pelvic ring fractures according to the Tile classification system. RESULTS: Pelvic fractures occurred more frequently in the pubis in the earthquake-related group than in the non-earthquake group (135/167, 81% vs. 48/70, 69%). In addition, comminuted fractures were more common in the earthquake-related group than in the non-earthquake group (55/167, 33% vs. 10/70, 14%). Multiple fractures were less common in the earthquake-related group than in the non-earthquake group (81/167, 49% vs. 46/70, 66%). Regarding the classification of pelvic ring fractures, Type C predominantly composed of subtype C3 occurred more frequently (64/167, 38% vs. 12/70, 17%), and Type A was less common in the earthquake-related group than in the non-earthquake group (31/167, 19% vs. 23/70, 32%). All differences were statistically significant (p<0.05). No difference was found in Type B fractures between the groups (72/167, 43% vs. 35/70, 50%). CONCLUSION: Earthquake-related pelvic crush fractures can be characterized by a high incidence of pelvic fractures occurring in the pubis, comminuted fractures, and Type C fractures predominantly composed by subtype C3, despite a low incidence of multiple fractures

    Electric power network fractal and its relationship with power system fault

    Get PDF
    Mreža elektro-energetskog sustava ima karakteristike fraktala. Ima osnovnu značajku složene mreže: sličnost samoj sebi. Autori su najprije izračunali vrijednosti fraktalne dimenzije za nekoliko elektro-energetskih rešetki, uključujući sustav 9 sabirnica WSCC (Western Systems Coordinating Council), sustav 14 sabirnica IEEE, sustav 30 sabirnica IEEE, sustav 39 sabirnica IEEE, sustav 118 sabirnica IEEE i sustav 300 sabirnica IEEE, kao i nekoliko stvarnih energetskih rešetki kao što su 500 kV glavne China Southern Power Grid (CSPG), 500 kV glavne energetske rešetke provincije Guangdong te 500 kV i 220 kV miješane energetske rešetke provincije Guangdong, itd. Na temelju fraktalne vrijednosti energetske rešetke analizirana je usporedba i odnos između fraktalne vrijednosti i intenziteta kvarenja energetskog sustava. Osnovni je zaključak da će za isti nivo napona, što je veća skala, energetska rešetka vjerojatno imati veću fraktalnu vrijednost i veći intenzitet kvarenja. Kod iste skale, što je gušća energetska rešetka to će vjerojatno biti veća fraktalna vrijednost i veći intenzitet kvarenja rešetke. Zaključci pružaju novi uvid u prosudbu statusa osjetljivosti energetskog sustava s interdisciplinarnog gledišta te voditi do novih smjerova u istraživanju.Electric power system network is with fractal characteristic. It has the basic feature of a complex network: self-similarity. The authors first calculated the fractal dimension values for several electric power grids, including WSCC (Western Systems Coordinating Council) 9 bus system, IEEE14 bus system, IEEE 30 bus system, IEEE 39 bus system, IEEE 118 bus system and IEEE 300 bus system; as well as some real power grids such as China Southern Power Grid (CSPG) 500 kV main power grid, Guangdong province 500 kV main power grid, and Guangdong province 500 kV and 220 kV mixed power grid, etc. Based on the power grid fractal value, a comparison and relationship between the fractal value and power system failure rate is analysed. The basic conclusion is that for the same voltage level, the larger the scale is, the larger fractal value and higher failure rate the power grid will possibly have. For the same scale, the denser the power grid, the larger fractal value and higher failure rate the power grid will probably have. The conclusions provide a new vision on the power system vulnerability status judgment from an interdisciplinary view and lead to a new research direction
    corecore