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As relativistic plasma launches from a compact object at the center of a galaxy, the corresponding outflow should slow down with the increase of separation from the core due to energy dissipation along the path. However, some long-baseline observations of active galactic nucleus (AGN) jets show that the velocity of jets increases rather than decreases at a larger and larger separation from the core. The mechanism of such an acceleration of astrophysical jets has not been well understood so far, although much progress has been achieved on theoretical and observational perspectives. This paper illustrates the phenomenon of jet acceleration that emerged in some AGNs by the nonballistic model in which some nonconsecutive knots are produced by a continuous outflow at different distances from the central black hole; such knots appear to rotate along different radii at the same precession cone in the case of a precessing jet. The projection of the trajectories of such knots on the plane of the sky leads us to expect that jet components further from the core move at larger apparent velocities. The investigation provides a very simple scenario to the puzzling phenomena of astrophysical jets.

Ghrelin is implicated in the regulation of gastric functional development. The octanoylation of ghrelin is critical for its physiological functions which dependent upon ghrelin O-acyltransferase (GOAT) catalyzation. To investigate the effect of GOAT on gastric acid secretion and expression of ghrelin in vitro. Primary cultures of gastric mucosal cells were challenged with 1.5 × 10

Fruit mulberry cultivation has become a new field of modern sericulture, and quite a number of studies were focused on the growth and development of mulberry flowers and fruits. In order to explore the molecular mechanism of development and regulation of mulberry pistillate flower, the total protein were extracted from the flowering style (with the stigma) and ovary with fruit mulberry variety "Da 10" as materials, separated by two-dimensional electrophoresis and identified by mass spectrometry. The results showed that there were significant differential expressions in different tissues, and 20 proteins with specific expression were detected in the style of pistillate flower. By mass spectrometry analysis, database retrieval and bioinformatics software analysis, these protein components were given functional annotation, mainly related to the biosynthetic metabolism of protein and flavonoid, stress response and redox reaction. Additionally, glucan endo-1,3-beta-glucosidase involved in cell wall metabolism was detected to be up-regulated expression and lipoxygenase participating in membrane lipid oxidation reaction was detected to be down-regulated expression in the style compared with that in the ovary. It illustrated that the differential expression of these proteins in style were closely related to pollen germination, pollen tube growth or intrusion of other xenobiotics.

Background There is increasing interest in the use of human amniotic fluid (AF) proteomics with surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) for diagnosing pregnancy-associated abnormalities. A critical parameter of diagnostic biomarkers is the accuracy and reproducibility of protein patterns. We evaluated the effects of common pretreatment protocols on protein patterns generated using SELDI mass spectrometry with two different protein capture strategies (including functional protein chips and functionalized magnetic beads prior to MS analysis) in AF. Method Various extrinsic factors involved in processing and storing amniotic fluid, including matrix composition, sample storage time, temperature and freeze–thaw cycles, were analyzed regarding their impact on AF protein patterns using SELDI mass spectrometry with 2 different protein capture strategies. Results Three extrinsic factors (sample storage for 3 days at either room temperature or 4 °C or freeze–thawing the sample 5 times) significantly decreased the number or intensities of protein peaks detected in AF. Matrix dilutions also changed the spectra of AF, with more peaks and higher intensities observed with 50% α-cyano-4-hydroxycinnamic acid (CHCA). Moreover, protein chips captured more proteins or peptides than magnetic beads on SELDI-TOF MS profiling of AF. Conclusions These results suggest that extrinsic factors must be taken into account for valid data interpretation to ensure good reproducibility of AF profiling by SELDI mass spectrometry.

There are two ways of expressing the precession of orbital plane of a binary pulsar system, given by Barker & O'Connell, Apostolatos et al. and Kidder, respectively. We point out that these two ways actually come from the same Lagrangian under different degrees of freedom. Damour & Schafer and Wex & Kopeikin applied Barker & O'Connell's orbital precession velocity in pulsar timing measurement. This paper applies Apostolatos et al.'s and Kidder's orbital precession velocity. We show that Damour & Schafer's treatment corresponds to negligible Spin-Orbit induced precession of periastron, while Wex & Kopeikin and this paper both found significant (but not equivalent) effects. The observational data of two typical binary pulsars, PSR J2051–0827 and PSR J1713+0747, apparently support a significant Spin-Orbit coupling effect. Specific binary pulsars with orbital plane nearly edge on could discriminate between Wex & Kopeikin and this paper: if the orbital period derivative of the double-pulsar system PSRs J0737–3039 A and B, with orbital inclination angle i = 87.7 −29 +17 deg, is much larger than that of the gravitational radiation induced one, then the expression in this paper is supported, otherwise Wex & Kopeikin's is supported.

We consider the problem of oscillation and nonoscillation solutions for unstable type second-order neutral difference equation : Δ2(x(n) - p(n)x(n - τ)) = q(n)x(g(n)).In this paper, we obtain some conditions for the bounded solutions of Eq(1) to be oscillatory and for the existence of the nonoscillatory solutions.

In this paper, we are mainly concerned with the classification of nonoscillatory solutions for the higher order difference equation and some existence results for some kinds of nonoscillatory solutions.

In this paper, we consider the oscillation of the second-order neutral difference equation $$\Delta ^2 \left( {x_n - px_{n - \tau } } \right) + q_n f\left( {x_{n - \sigma _n } } \right) = 0$$ as well as the oscillatory behavior of the corresponding ordinary difference equation $$\Delta ^2 z_n + q_n f\left( {R\left( {n,\lambda } \right)z_n } \right) = 0$$ .

In order to study total dose radiation effects of PbZrxTi1-xO3 (PZT) film made with the pulsed excimer laser deposition (PLD) technique, hysteresis loops and capacitance-voltage (C-V) curves of PZT film capacitors have been measured before and after gamma-ray irradiation. The results show that, in a range of 0-2 x 10(5) Gy (Si), with increasing total dose, the remanent polarization 2P(r) increased while dielectric constant epsilon decreased. This can be explained by charges trapped by some defects during irradiation.

Although much attention has been paid to Al-Cu-Li-Mg-Ag-Zr alloys, there are sparse reports about the influence of Li on precipitation in these alloys. The aim of the present study is to determine the effects of Li on modifying precipitation in a baseline aluminum alloy 2195 and the accompanying variants with 0--1.6 wt.% Li.

We investigate the properties of bulk superconductors in weakly static electric fields by a stationary perturbation method applied to the Schrodinger equation.

Angiotensin-converting enzyme 2 (ACE2) is a newly discovered homolog of ACE whose actions oppose those of angiotensin II (AngII). However, the underlying mechanisms by which ACE2 effectively suppresses early atherosclerotic lesions remain poorly understood. Here, we show, both in vitro and in vivo, that ACE2 inhibited the development of early atherosclerotic lesions by suppressing the growth of vascular smooth muscle cells (VSMCs) and improving endothelial function. In a relatively large cohort animal study (66 rabbits), aortic segments transfected by Ad-ACE2 showed significantly attenuated fatty streak formation, neointimal macrophage infiltration, and alleviation of impaired endothelial function. Segments also showed decreased expression of monocyte chemoattractant protein 1, lectin-like oxidized low-density lipoprotein receptor 1, and proliferating cell nuclear antigen, which led to the delayed onset of atherosclerotic lesions. At the cellular level, ACE2 significantly modulated AngII-induced growth and migration in human umbilical vein endothelial cells and VSMCs. The antiatherosclerotic effect of ACE2 involved down-regulation of the ERK-p38, JAK-STAT, and AngII-ROS-NF-κB signaling pathways and up-regulation of the PI3K-Akt pathway. These findings revealed the molecular mechanisms of the antiatherosclerotic activity of ACE2 and suggested that modulation of ACE2 could offer a therapeutic option for treating atherosclerosis.

The purpose of this study was to test the hypothesis that overexpression of angiotensin-converting enzyme 2 (ACE2) may favorably affect left ventricular (LV) remodeling and function after myocardial infarction (MI). The left anterior descending coronary artery was ligated to produce anterior MI in 100 Wistar-Kyoto rats that were randomly divided into Ad-ACE2, Ad-ACE2+A779, Ad-EGFP, model, and sham groups. Two weeks later, rats in the Ad-ACE2 and Ad-EGFP groups received direct intramyocardial injection of Ad-ACE2 and Ad-EGFP, respectively. Rats in the Ad-ACE2+A779 group received both intramyocardial injection of Ad-ACE2 and a continuous intravenous infusion of A779 for 15 days. LV volume and systolic function, the extent of myocardial fibrosis, and levels of ACE2, angiotensin II (Ang II), and collagen I protein expression were evaluated. Four weeks after ACE2 gene transfer, the Ad-ACE2 group showed reduced LV volume, extent of myocardial fibrosis, and expression levels of ACE, Ang II, and collagen I in the myocardium, and increased LV ejection fraction and levels of ACE2 activity and expression in comparison with the Ad-EGFP and model groups. These results suggest that ACE2 overexpression attenuated LV fibrosis and improved LV remodeling and systolic function. In conclusion, overexpression of ACE2 favorably affected the pathological process of LV remodeling after MI by inhibiting ACE activity, reducing AngII levels, and up-regulating Ang-(1-7) expression, thus providing a potential therapeutic target in the treatment of heart failure.

Objective— The purpose of this study was to test the hypothesis that ACE2 overexpression may enhance atherosclerotic plaque stability by antagonizing ACE activity and converting angiotensin II to angiotensin 1–7. Methods and Results— Atherosclerotic plaques were induced in the abdominal aorta of 114 rabbits by endothelial injury and atherogenic diet. Gene therapy was performed in group A at week 4 and in group B at week 12, respectively. Each group of rabbits were randomly divided into 3 subgroups which received, respectively, a recombinant ACE2 expressing vector (AdACE2), a control vector AdEGFP and AdACE2+A779, an antagonist of angiotensin 1–7 receptor. Local ACE2 overexpression attenuated the progression of lesions from week 4 to week 8, but not progression of plaque size from week 12 to week 16. In group B rabbits, local ACE2 overexpression resulted in stable plaque compositions, ie, fewer macrophages, less lipid deposition and more collagen contents, higher plaque stability scores, decreased angiotensin II levels, and increased angiotensin 1–7 levels in plaque tissues in the AdACE2 subgroup compared with those in the AdEGFP subgroup. Conclusions— Overexpression of ACE2 results in stabilized atherosclerotic plaques and the mechanism is probably the conversion of vasoconstrictive angiotensin II to vessel protective angiotensin 1–7.

The purpose of the current study was to investigate the changes of serum proteome and discover potential biomarkers for Kashin-Beck disease (KBD) using surface-enhanced laser desorption ionization mass spectrometry (SELDI-TOF MS). The serum protein profiles from 102 cases (36 KBD patients, 16 controls in KBD areas, 33 controls in non-KBD areas, and 17 osteoarthritis controls) were detected by SELDI-TOF MS and weak cation-exchange protein chip. Differently expressed peaks in KBD were identified by comparing the data among the four groups using the nonparametric Mann-Whitney test with Bonferroni correction at a significance level of 0.05. Then, those 102 cases were used to generate a classification tree as the training set, and an additional 34 cases were collected as the test set. A classification tree was generated by Biomarker Patterns Software (Ciphergen). Multiple protein changes were detected in the KBD group, including three potential biomarkers (15 886, 5336, 6113 m/z). A classification tree with three distinct proteins was generated. The classification tree was able to distinguish the KBD patients from the controls with 88.89% specificity and 86.36% sensitivity. The study demonstrates that marked serum proteomic changes exist in KBD. The proteins represented by the differently expressed peaks are candidate biomarkers for KBD.

C-axis oriented Y1Ba2Cu3O7-x (YBCO) thin films and PbZr0.52Ti0.48O3 (PZT)/(YBCO) heterostructures were deposited on single-crystal LaAlO3 by Nd:YAG pulsed laser deposition. The results showed that the YBCO films exhibited superconducting transition temperature above 86 K and ion beam channeling minimum yields χmin of 49%, indicating the relatively good quality of YBCO films deposited on the LaAlO3 substrate. The PZT films in situ grown on the YBCO films were epitaxially c-axis oriented with a saturation polarization and remanence as high as 57μC/cm2 and 39μC/cm2 (at 204 kV/cm), respectively. The coercive field of PZT films is about 55 kV/cm.