Search

The acceleration mechanisms of relativistic jets are of great importance for understanding various astrophysical phenomena such as gamma-ray bursts, active galactic nuclei and microquasars. One of the most popular scenarios is that the jets are initially Poynting-flux dominated and succumb to magnetohydrodynamic instability leading to magnetic reconnections. We suggest that the reconnection timescale and efficiency could strongly depend on the geometry of the jet, which determines the length scale on which the orientations of the field lines change. In contrast to a usually-assumed conical jet, the acceleration of a collimated jet can be found to be more rapid and efficient (i.e. a much more highly saturated Lorentz factor can be reached) while the jets with lateral expansion show the opposite behavior. The shape of the jet could be formed due to the lateral squeezing on the jet by the stellar envelope of a collapsing massive star or the interaction of the jet with stellar winds.

This paper simplifies the dish-shaped metal corrugated pipe into a elastic element, constitutes a single degree of freedom spring-mass system, then applicants the random vibration method to measure its natural frequency, further to calculate the dynamic stiffness of dish-shaped metal corrugated pipe. At the same time its static stiffness test is done. By comparison of two results, static and dynamic stiffness values fit well, and dynamic stiffness is closer to the actual working conditions. Random vibration method for dynamic stiffness is convenient, accurate and has application values in a wide range of engineering.

Detailed information of the 36 single copy nuclear genes used in this study. (DOCX 22Â kb)

Detailed information of the chloroplast and nuclear genes used in this study. (DOCX 58Â kb)

Nucleotide variation patterns of the 36 single copy nuclear genes used in this study. (DOCX 34Â kb)

Accession numbers of the Panax species and outgroups used in this study. (DOCX 23Â kb)

Accession numbers of the Panax species and outgroups used in this study. (DOCX 23Â kb)

Accessions of Panax species and outgroups sampled from the 36 single copy nuclear genes. (DOCX 43Â kb)

To establish a green fluorescent protein (GFP)- based cellular model for screening GLP-1 receptor ligands from Traditional Chinese Medicinal herbs. A eukaryotic expression vector pCMV6-GLP-1R-GFP was constructed and transfected into U20S cells. A stable expressing GLP- 1R-GFP U20S cell line was established and the expression of GLP-1 receptor was confirmed by Western Blots with a GLP-1 specific antibody. The activities of expressed GLP-1- GFP were investigated with the cellular redistribution of green fluorescence after stimulation with GLP-1 analogs in the absence or presence of a GLP-1 antagonist. The sensitivity and specificity of this cell line was qualified and suitable for GLP-1 receptor ligand screening. Keywords-GLP-1receptor; GLP-1-GFP/U2OS cell line; Type2 diabetics. I. INTRODUCTION The glucagon-like peptide-1 receptor (GLP-1R) is a therapeutically important family B G-protein-coupled receptor (GPCR) that is pleiotropically coupled to multiple signaling effectors, and with activities including regulation of insulin biosynthesis and secretion, GLP-1R is one of the key targets in the management of type II diabetes mellitus (DM) (1). GLP-1 is an incretin hormone secreted by intestine L-cells in response to nutrient ingestion and is responsible for up to 70% of the insulin response after a meal (2). After release, GLP-1 potentiates glucose-dependent insulin secretion (3), inhibits glucagon secretion (4), and increases β-cell mass by means of inducing β-cell proliferation and inhibiting the apoptosis of β-cell (5). The release of GLP-1 further induces satiety, delays gastric emptying, and has potential effects in both cardiovascular and nervous systems. Compared with conventional treatment for type II DM, GLP-1 promotes insulin release only in the context of hyperglycemia, so that it does not cause hypoglycemia in human (6). However, the promise of this receptor as a drug target for type II DM is hindered by the rapid degradation of endogenous peptides by dipeptidyl peptidase IV (DPPIV) in vivo. This has in part been overcome by the development of DPPIV-resistant GLP-1 mimetics such as exendin-4 and liraglutide as well as DPPIV inhibitors that prolong the plasma half-life of endogenous GLP-1R peptides (7,8). Although these have therapeutic potential (indeed, exendin-4 is currently used clinically), frequent intravenous or subcutaneous administration are required for these GLP-1 analogs for clinical uses, which can reduce patients' compliance. In addition, exendin-4 has also been associated with significant adverse side effects in some patients, including pancreatitis (9), of which the mechanistic basis is unknown. These difficulties have therefore driven the search for the development of small molecules orally active drugs that induce GLP-1R signaling. In this study, GFP-tagged GLP-1R stably expressed cell lines was constructed, and the cell model was validated, we will use this GLP-1-GFP/U2 cells to screen small molecule ligands of GLP-1R from Yunnan abundant natural medicinal resources. II. MATERIALS AND METHODS A. Materials

Detailed information of the 36 single copy nuclear genes used in this study. (DOCX 22Â kb)

Accessions of Panax species and outgroups sampled from the 36 single copy nuclear genes. (DOCX 43Â kb)

Detailed information of the chloroplast and nuclear genes used in this study. (DOCX 58Â kb)

Nucleotide variation patterns of the 36 single copy nuclear genes used in this study. (DOCX 34Â kb)

The point kinetic equations are the system of a couple stiff ordinary differential equations. Many studies have focused on the development of more advanced and efficient methods of solving the equations, such as the high order Taylor polynomials method, the Haar wavelet operational method, the fractional point-neutron kinetic model method, the basis function method, the homotopy analysis method, and other methods. Most of these methods are successful in some specific problems, but still have, more or less, disadvantages. For example, the accuracy of the Haar wavelet operational method is limited by the collocation points, and it needs more computing time for a high precision. Aiming at the requirements that some numerical calculation results must have the higher precision and only the positive error in the nuclear reactor safety engineering and ship reactor for the maneuverability, in this paper we try to look for a new numerical method to satisfy that the calculation value is slightly higher than the real value when the actual curve is upward convex or downward concave, and the error is not greater than that by the Euler and improved Euler method. The new method is so-called the curvature weight (CW) method, which is based on the curvature circle method and considers the contributions of two curvatures at the interval step point to the average curvature inside the interval step. Using the decoupling method to remove the stiffness of equations and the instantaneous jump approximation to derive the neutron differential equations, the first and second derivative of neutron density are obtained. Then the CW method is used to solve the point reactor neutron kinetic equations, and thus obtaining the numerical solution. Compared with the results by the Euler and improved Euler method, the numerical calculation results by the CW method are always higher than the real value, and the calculation accuracy and speed are improved significantly. When this new method is used to solve the point reactor neutron differential equations with the step and linear reactivity inserted into the subcritical reactor, the numerical results which satisfy the requirements of positive calculation error and high precision can be obtained quickly. After improving the calculation step length, the precision reduction by the CW method is significantly lower than that by the Euler and improved Euler method. So the CW method can greatly shorten the total computing time, and it is also effective for most of differential equation systems.

Based on the resonating valence bond theory, the linear combinations of the main orbits occupied by liquid hydrogen electrons are selected as the basis sets to construct the Jastrow antisymmetrized geminal product. The resonating valence bond (RVB) wave function which takes into consideration electron correlation effects provides lower energy than the local density approximation (LDA) function. In order to improve the nodal accuracy of the variational trial wave function, the backflow correlations are suggested to be employed whenever rs1.75 or T 15000 K, the improved wave function has about 1 mHa/atom decrease in local energy with respect to the one without backflow effects at the VMC level, and has a lower variance simultaneity. After combining the coupled electron-ion Monte Carlo (CEIMC) method with the RVB wave function, the simulation results we have obtained are in good agreement with the experimental and other ab-initio ones; the deuterium principal Hugoniot curve passing through the error bars of various existing experiments conducted via different high-pressure technologies has a maximum compression of 4.48 at about 50.3GPa, but the phenomenon of apparent increase in compression ratio along the Hugoniot between 100120 GPa has not been found. The RVB wave function discussed in this paper when adopted the CEIMC method is not only quite suitable for the simulation of liquid hydrogen within a wide range of density and temperature (1.0 rs2.2, 2800 K T60000 K), but also can give some more applicable thermodynamic properties of hydrogen under shock loading.