625 research outputs found
Probing neutral top-pion via a flavor-changing process
In the framework of topcolor-assisted-technicolor model(TC2), we study a
flavor-changing neutral top-pion production process . The study shows that there exists a resonance effect
which can enhance the cross section up to a few fb even tens fb. For a yearly
luminosity 100 at future linear colliders, there might be hundreds
even thousands events to be produced. On the other hand, the background of such
flavor-changing process is very clean due to the GIM mechanism in SM . With
such sufficient events and clean background, neutral toppion could be detected
at future linear colliders with high center of energy and luminosity. Our study
provides a possible way to test TC2 model.Comment: 10 pages, 4 figures,has been accepted by Phys.Rev.
Lepton flavor violation decays in the topcolor-assisted technicolor model and the littlest Higgs model with parity
The new particles predicted by the topcolor-assisted technicolor ()
model and the littlest Higgs model with T-parity (called model) can
induce the lepton flavor violation () couplings at tree level or one loop
level, which might generate large contributions to some processes. Taking
into account the constraints of the experimental data on the relevant free
parameters, we calculate the branching ratios of the decay processes
with = , and
in the context of these two kinds of new physics models. We find
that the model and the model can indeed produce significant
contributions to some of these decay processes.Comment: 24 pages, 7 figure
The rare top quark decays in the topcolor-assisted technicolor model
We consider the rare top quark decays in the framework of topcolor-assisted
technicolor (TC2) model. We find that the contributions of top-pions and
top-Higgs predicted by the TC2 model can enhance the SM branching ratios by as
much as 6-9 orders of magnitude. i.e., in the most case, the orders of
magnitude of branching ratios are , , . With the reasonable values of the
parameters in TC2 model, such rare top quark decays may be testable in the
future experiments. So, rare top quark decays provide us a unique way to test
TC2 model.Comment: 14 pages, 4 figure
RE: "Trends in 'Deaths of Despair' Among Working-Aged White and Black Americans, 1990-2017"
In a recent article by Tilstra et al., the authors characterize mortality rates from suicide, drug use, and alcohol use stratified by sex and race, with the goal of comparing non-Hispanic Black and non-Hispanic White death rates related to these “deaths of despair.” We commend the authors for this important work. The authors used data from the National Vital Statistics System and US Census to assess cause-specific mortality trends stratified by race and sex and found parallels in mortality trends for Black and White adults with respect to the opioid epidemic and the Great Recession. The authors did not observe period or cohort increases in suicide for Black men and women, stating that this finding warrants further study. Measurement error could underlie some of the unexpected trends the authors identified. One potential source of error is differential misclassification of suicide by race in the US National Center for Vital Statistics data. The authors cite a study that found the odds of suicide misclassification as “undetermined intent” was twice as high in Black populations compared with White populations. Additionally, the National Center of Health Statistics found evidence that deaths are overreported differentially in White and Black populations (overestimates of 1% and 5%, respectively), which may be related to historical undercounting of certain populations, including Black and Hispanic populations, in the Census denominator of the mortality rate
Nanoemulsions for drug delivery
Emulsions are liquid–liquid dispersions with one liquid phase dispersed in the other liquid phase as small droplets. Nanoemulsions are nano-sized emulsions with sizes ranging from tens to hundreds of nanometers, and have great potential applications in pharmaceutics, foods and cosmetics due to their attractive properties, such as small sizes, high surface area per unit volume, improved dispersion of active hydrophobic components and enhanced absorption. The article provides an overview of nanoemulsions for drug delivery, starting with an introduction of emulsion types, nanoemulsion preparation and nanoemulsion stability. Surfactants play critical roles in producing and stabilizing nanoemulsions. Different types of surfactants are summarized including small molecule surfactants, particle surfactants, phospholipids, peptide and protein surfactants. Then the applications of nanoemulsions as nanomedicine in drug delivery are presented. Finally, clinical applications of nanoemulsions are discussed.Russell J. Wilson, Yang Li, Guangze Yang, Chun-Xia Zha
First Report of Alternaria Black Spot Disease Caused by Alternaria alternata on the Invasive Weed Solanum rostratum in Xinjiang, China
Solanum rostratum is a noxious weed, native to Mexico and the USA, which has invaded Liaoning, Jilin, Hebei, Inner
Mongolia, Shanxi, Xinjiang and Beijing, China (Eminniya et al., 2013). In August 2015, foliar symptoms of yellowish to black
spots were observed on plants of S. rostratum nearby an agricultural plantation in Changji, Xinjiang. The following year, about
17% of the 206 plants surveyed on about 0.2 ha of deserted farmland were infected from July-September (at 19-35°C under
29-97% RH)
Revisión sobre métodos de preparación, mecanismos y aplicaciones de péptidos antioxidantes en aceites
Natural antioxidants, especially those used in edible oil, are safer compared to chemically synthesized antioxidants. Therefore, research on natural antioxidants has become prevelant. Antioxidant peptides derived from food protein can effectively prevent oil oxidation. Protein hydrolyzation is widely applied for the production of antioxidant peptides in industry, and bioinformatics is employed nowadays to generate the desired peptide sequence. Furthermore, the mechanism of antioxidant peptides in the oil system is still controversial, which limits the further development of antioxidant peptides as food antioxidants. This review introduces the preparation method of antioxidant peptides and their mechanisms as well as applications in the oil. It will help to comprehensively understand the function of antioxidant peptides and promote their development in the oil field.Los antioxidantes naturales, especialmente utilizados en aceites comestibles, son más seguros en comparación con los antioxidantes sintetizados químicamente. Por lo tanto, la investigación sobre antioxidantes naturales se convierte en un punto de interés. Los péptidos antioxidantes derivados de las proteínas alimentarias pueden prevenir eficazmente la oxidación del aceite. La hidrolización de proteínas se usa ampliamente en la industria para la producción de péptidos antioxidantes y la bioinformática se emplea hoy en día para generar la secuencia de péptidos deseada. Además, el mecanismo de los péptidos antioxidantes en el sistema oleoso sigue siendo controvertido, lo que limita el desarrollo posterior de péptidos antioxidantes como antioxidantes alimentarios. Esta revisión presenta el método de preparación de péptidos antioxidantes y su mecanismo, así como las aplicaciones en aceite, lo que ayudará a comprender de manera integral la función de los péptidos antioxidantes y promoverá su desarrollo en el campo petrolero
Finite element assessment of the temperature field couple under joule heat and friction heat between a third rail and collector shoe
Based on the finite element software COMSOL Multiphysics 4.3b, a temperature field model for an aluminium/stainless steel composite third rail and a copper impregnated carbon collector shoe contact with coupling of joule heat and friction heat was established. A method of coupling the two kinds of heat was developed, the temperature fields were calculated, and the maximum coupled temperature change under different electric current, normal forces, sliding velocities and sliding distances were studied. The results show that the temperature distribution expands around the contact area in a descending tendency at positions closer to the electric contact area and the temperature gradients are higher; the maximum coupled temperature increases with an increase of electric current; with an increase of normal force, the maximum coupled temperature initially decreases then increases; the maximum coupled temperature increases initially then gradually becomes stable with an increase of sliding distance; an optimal normal force range exists in frictional sliding with an electric current, at which the maximum coupled temperature is at its lowest; joule heat and friction heat are competitive with each other. When normal force is lower, the joule heat becomes the main heat source, but when normal force is greater, mechanical friction heat becomes the main heat source
- …