38,779 research outputs found
Electronic visualization of gas bearing behavior
Visualization technique produces a visual simulation of gas bearing operation by electronically combining the outputs from the clearance probes used to monitor bearing component motion. Computerized recordings of the probes output are processed, displayed on an oscilloscope screen and recorded with a high-speed motion picture camera
Spin-transfer mechanism for magnon-drag thermopower
We point out a relation between the dissipative spin-transfer-torque
parameter and the contribution of magnon drag to the thermoelectric
power in conducting ferromagnets. Using this result we estimate in iron
at low temperatures, where magnon drag is believed to be the dominant
contribution to the thermopower. Our results may be used to determine
from magnon-drag-thermopower experiments, or, conversely, to infer the strength
of magnon drag via experiments on spin transfer
Relativistic Modification of the Gamow Factor
In processes involving Coulomb-type initial- and final-state interactions,
the Gamow factor has been traditionally used to take into account these
additional interactions. The Gamow factor needs to be modified when the
magnitude of the effective coupling constant increases or when the velocity
increases. For the production of a pair of particles under their mutual
Coulomb-type interaction, we obtain the modification of the Gamow factor in
terms of the overlap of the Feynman amplitude with the relativistic wave
function of the two particles. As a first example, we study the modification of
the Gamow factor for the production of two bosons. The modification is
substantial when the coupling constant is large.Comment: 13 pages, in LaTe
Neuroprotective roles of asiaticoside on hydrogen peroxide-induced toxicity in SH-SY5Y cells
This study aims to determine whether the neuroprotective role of asiaticoside at maximum non-toxic dose (MNTD) or half MNTD (½MNTD) on H2O2-induced neurotoxicity in SH-SY5Y cells was mediated by regulation of reactive oxygen species (ROS) and nitric oxide (NO) through inducible nitric oxide synthase (iNOS) and heme-oxygenase 1 (HO-1). The levels of ROS, NO, iNOS and HO-1 in SH-SY5Y cells pre-treated with asiaticoside ½MNTD were significantly reduced by 15.3, 55.6, 24.8 and 6.7 %, respectively as compared to the H2O2 treatment group. Cells pre-treated MNTD only reduced the iNOS level significantly. Asiaticoside, particularly at ½MNTD reduced the ROS, NO and iNOS levels. Contrarily, the HO-1 expression was down-regulated when treated with asiaticoside, which further suggest that asiaticoisde exerted its neuroprotective effects via HO-1 regulation.Keywords: Asiaticoside; Heme-oxygenase 1; Inducible nitric oxide synthase; Nitric oxide; Reactive oxygen species
A heparin-mimicking polymer conjugate stabilizes basic fibroblast growth factor.
Basic fibroblast growth factor (bFGF) is a protein that plays a crucial role in diverse cellular functions, from wound healing to bone regeneration. However, a major obstacle to the widespread application of bFGF is its inherent instability during storage and delivery. Here, we describe the stabilization of bFGF by covalent conjugation with a heparin-mimicking polymer, a copolymer consisting of styrene sulfonate units and methyl methacrylate units bearing poly(ethylene glycol) side chains. The bFGF conjugate of this polymer retained bioactivity after synthesis and was stable to a variety of environmentally and therapeutically relevant stressors--such as heat, mild and harsh acidic conditions, storage and proteolytic degradation--unlike native bFGF. Following the application of stress, the conjugate was also significantly more active than the control conjugate system in which the styrene sulfonate units were omitted from the polymer structure. This research has important implications for the clinical use of bFGF and for the stabilization of heparin-binding growth factors in general
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ZNF750 is a lineage-specific tumour suppressor in squamous cell carcinoma.
ZNF750 controls epithelial homeostasis by regulating epidermal-differentiation genes, a role underscored by its pathogenic mutations in esophageal squamous cell cancers (SCCs). However, the precise role of ZNF750 in SCC cell biology remains unclear. In this study, we report that ZNF750 is exclusively deleted, mutated and underexpressed in human SCCs, and low ZNF750 expression is associated with poor survival. Restoration of wildtype, but not mutant ZNF750 protein uniquely inhibited the malignant phenotypes of SCC cells both in vitro and in vivo. Notably, ZNF750 promoted the expression of a long non-coding RNA (TINCR), which mediated both cancer-inhibition and differentiation-induction effects of ZNF750. In addition, ZNF750 potently suppressed cell migration by directly inhibiting the transactivation of LAMC2. Together, our findings characterize ZNF750 as a crucial SCC-specific suppressor and uncover its novel anticancer-associated functions
Dissociation rates of J/psi's with comoving mesons - thermal vs. nonequilibrium scenario
We study J/psi dissociation processes in hadronic environments. The validity
of a thermal meson gas ansatz is tested by confronting it with an alternative,
nonequilibrium scenario. Heavy ion collisions are simulated in the framework of
the microscopic transport model UrQMD, taking into account the production of
charmonium states through hard parton-parton interactions and subsequent
rescattering with hadrons. The thermal gas and microscopic transport scenarios
are shown to be very dissimilar. Estimates of J/psi survival probabilities
based on thermal models of comover interactions in heavy ion collisions are
therefore not reliable.Comment: 12 pages, 6 figure
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