1,249 research outputs found
Top quark spin and interaction in charged Higgs and top quark associated production at LHC
We study the charged Higgs production at LHC via its associated production
with top quark. The kinematic cuts are optimized to suppress the background
processes so that the reconstruction of the charged Higgs and top quark is
possible. The angular distributions with respect to top quark spin are explored
to study the interaction at LHC.Comment: 10 pages,5 figures, to appear in PR
Relation between axial length and ocular parameters
AIM: To investigatethe relation between axial length(AL), age and ocular parameters.<p>METHODS: A total of 360 subjects(360 eyes)with emmetropia or myopia were recruited. Refraction, center corneal thickness(CCT), AL, intraocular pressure(IOP)were measured by automatic-refractor, Pachymeter, A-mode ultrasound and non-contact tonometer, respectively. Corneal curvature(CC), anterior chamber depth(ACD)and white-to-white distance(WWD)were measured by Orbscan II. Three dimensional frequency domain coherent optical tomography(3D-OCT)was used to examine the retinal nerve fiber layer thickness(RNFLT). The Pearson correlation coefficient(<i>r</i>)and multiple regression analysis were performed to evaluate the relationship between AL, age and ocular parameters.<p>RESULTS: The average AL was 24.15±1.26mm. With elongation of the AL, spherical equivalent(SE)(<i>r</i>=-0.742,<i>P</i><0.01), CC(<i>r</i>=-0.395, <i>P</i><0.01)and RNFLT(<i>r</i>=-0.374, <i>P</i><0.01)all decreased, while the mean ACD(<i>r</i>=0.411, <i>P</i><0.01)increased. On the contrary, there was not statistical significan with CCT(<i>r</i>=0.099, <i>P</i>=0.060)and WWD(<i>r</i>=0.061, <i>P</i>=0.252). There was also a significant correlation between AL and age(<i>P</i>=0.001), SE(<i>P</i><0.001), ACD(<i>P</i><0.001), CC(<i>P</i><0.001)in Multiple linear regression analysis.<p>CONCLUSION: In longer eyes, there is a tendency toward myopia, a flatter cornea, a deeper ACD and a thinner RNFLT. Age is an influencing factor for the AL as well
XMM-Newton observation of the eclipsing binary Algol
We present an {\sl XMM-Newton} observation of the eclipsing binary Algol
which contains an X-ray dark B8V primary and an X-ray bright K2IV secondary.
The observation covered the optical secondary eclipse and captured an X-ray
flare that was eclipsed by the B star. The EPIC and RGS spectra of Algol in its
quiescent state are described by a two-temperature plasma model. The cool
component has a temperature around 6.4 K while that of the hot
component ranges from 2 to 4.0 K. Coronal abundances of C, N, O,
Ne, Mg, Si and Fe were obtained for each component for both the quiescent and
the flare phases, with generally upper limits for S and Ar, and C, N, and O for
the hot component. F-tests show that the abundances need not to be different
between the cool and the hot component and between the quiescent and the flare
phase with the exception of Fe. Whereas the Fe abundance of the cool component
remains constant at 0.14, the hot component shows an Fe abundance of
0.28, which increases to 0.44 during the flare. This increase is
expected from the chromospheric evaporation model. The absorbing column density
of the quiescent emission is 2.5 cm, while that of
the flare-only emission is significantly lower and consistent with the column
density of the interstellar medium. This observation substantiates earlier
suggestions of the presence of X-ray absorbing material in the Algol system.Comment: 15 pages, 9 figures, Accpted by RA
The Biological Behaviors of Rat Dermal Fibroblasts Can Be Inhibited by High Levels of MMP9
Aims. To explore the effects of the high expression of MMP9 on biological behaviors of fibroblasts. Methods. High glucose and hyperhomocysteine were used to induce MMP9 expression in skin fibroblasts. Cell proliferation was detected by flow cytometry and cell viability by CCK-8. ELISA assay was used to detect collagen (hydroxyproline) secretion. Scratch test was employed to evaluate horizontal migration of cells and transwell method to evaluate vertical migration of cells. Results. The mRNA and protein expressions of MMP9 and its protease activity were significantly higher in cells treated with high glucose and hyperhomocysteine than those in control group. At the same time, the S-phase cell ratio, proliferation index, cell viability, collagen (hydroxyproline) secretion, horizontal migration rate, and the number of vertical migration cells decreased in high-glucose and hyperhomocysteine-treated group. Tissue inhibitor of metalloproteinase 1 (TIMP1), which inhibits the activity of MMP9, recovered the above biological behaviors. Conclusions. High expression of MMP9 in skin fibroblasts could be induced by cultureing in high glucose and hyperhomocysteine medium, which inhibited cell biological behaviors. Inhibitions could be reversed by TIMP1. The findings suggested that MMP9 deters the healing of diabetic foot ulcers by inhibiting the biological behaviors of fibroblasts
Myoplasmic resting Ca2+ regulation by ryanodine receptors is under the control of a novel Ca2+-binding region of the receptor
Passive SR (sarcoplasmic reticulum) Ca2+ leak through the RyR (ryanodine receptor) plays a critical role in the mechanisms that regulate [Ca2+ ]rest (intracellular resting myoplasmic free Ca2+ concentration) in muscle. This process appears to be isoform-specific as expression of either RyR1 or RyR3 confers on myotubes different [Ca2+ ]rest. Using chimaeric RyR3–RyR1 receptors expressed in dyspedic myotubes, we show that isoformdependent regulation of [Ca2+ ]rest is primarily defined by a small region of the receptor encompassing amino acids 3770– 4007 of RyR1 (amino acids 3620–3859 of RyR3) named as the CLR (Ca2+ leak regulatory) region. [Ca2+ ]rest regulation by the CLR region was associated with alteration of RyRs’ Ca2+ - activation profile and changes in SR Ca2+ -leak rates. Biochemical analysis using Tb3+ -binding assays and intrinsic tryptophan fluorescence spectroscopy of purified CLR domains revealed that this determinant of RyRs holds a novel Ca2+ -binding domainwith conformational properties that are distinctive to each isoform. Our data suggest that the CLR region provides channels with unique functional properties that modulate the rate of passive SR Ca2+ leak and confer on RyR1 and RyR3 distinctive [Ca2+ ]rest regulatory properties. The identification of a new Ca2+ -binding domain ofRyRswith a key modulatory role in [Ca2+ ]rest regulation provides new insights into Ca2+ -mediated regulation of RyRs
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