Blazars are an extreme subclass of active galactic nuclei. Their rapid variability, luminous brightness, superluminal motion, and high and variable polarization are probably due to a beaming effect. ...However, this beaming factor (or Doppler factor) is very difficult to measure. Currently, a good way to estimate it is to use the timescale of their radio flares. In this Letter, we use multiwavelength data and Doppler factors reported in the literature for a sample of 86 flaring blazars detected by Fermi to compute their intrinsic multiwavelength data and intrinsic spectral energy distributions and investigate the correlations among observed and intrinsic data. Quite interestingly, intrinsic data show a positive correlation between luminosity and peak frequency, in contrast with the behavior of observed data, and a tighter correlation between γ-ray luminosity and the lower-energy ones. For flaring blazars detected by Fermi, we conclude that (1) observed emissions are strongly beamed; (2) the anti-correlation between luminosity and peak frequency from the observed data is an apparent result, the correlation between intrinsic data being positive; and (3) intrinsic γ-ray luminosity is strongly correlated with other intrinsic luminosities.
Exposure of cells to colloidal nanoparticles (NPs) can have concentration-dependent harmful effects. Mostly, such effects are monitored with biochemical assays or probes from molecular biology, i.e., ...viability assays, gene expression profiles, etc., neglecting that the presence of NPs can also drastically affect cellular morphology. In the case of polymer-coated Au NPs, we demonstrate that upon NP internalization, cells undergo lysosomal swelling, alterations in mitochondrial morphology, disturbances in actin and tubulin cytoskeleton and associated signaling, and reduction of focal adhesion contact area and number of filopodia. Appropriate imaging and data treatment techniques allow for quantitative analyses of these concentration-dependent changes. Abnormalities in morphology occur at similar (or even lower) NP concentrations as the onset of reduced cellular viability. Cellular morphology is thus an important quantitative indicator to verify harmful effects of NPs to cells, without requiring biochemical assays, but relying on appropriate staining and imaging techniques.
Free thiol groups of intra and extracellular molecules are considered to be antioxidative and to protect cells from damage caused by free radicals. However, the associations of serum total thiol ...levels (TTL) with the incidences of the four most frequent cancer sites have not yet been investigated in a large population‐based, prospective study. TTL was measured in case–cohort design in a sample from the population‐based, Norwegian Tromsø 3 study (cancer cases: n = 941; random subcohort: n = 1,000) and was repeatedly measured at Tromsø 5. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated by weighted multivariable‐adjusted Cox regression with time‐dependent modeling of TTL for incident lung, colorectal, breast and prostate cancer. High serum TTL were associated with a reduced risk of all four major cancers. The associations with lung (top vs. bottom tertile: HR, 0.64; 95% CI, 0.41, 0.99) and breast cancer (top vs. bottom tertile: HR, 0.64; 95% CI, 0.42, 0.96) were statistically significant, whereas associations with colorectal (top vs. bottom tertile: HR, 0.79; 95% CI, 0.54, 1.16) and prostate cancer (top vs. bottom tertile: HR, 0.79; 95% CI, 0.53, 1.17) were not statistically significant but pointed in the same protective direction. These findings from a large, prospective Norwegian cohort study suggest a preventive role of thiols against the development of the four most frequent cancers. Whereas associations with breast and lung cancer could be shown with statistical significance, larger studies are needed to corroborate potential associations of TTL with colorectal and prostate cancer.
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Circulating free radicals can damage DNA, cause havoc in cells, and induce cancer. Thiols are part of the body's system to clean up those harmful molecules, and serum total thiol levels (TTL) can serve as a reflection of the body's antioxidant capacity. Here, the authors assessed the relationship between thiol levels and risk of four common cancers. Using data from a large Norwegian cohort study, the authors found a statistically significant association between high TTL and reduced risk of breast cancer or lung cancer, and a weaker association with colorectal and prostate cancer.
We use a large N-body simulation to study the relation of the structural properties of dark matter halos to their assembly history and environment. The complexity of individual halo assembly ...histories can be well described by a small number of principal components (PCs), which, compared to formation times, provide a more complete description of halo assembly histories and have a stronger correlation with halo structural properties. Using decision trees built with the random ensemble method, we find that about 60%, 10%, and 20% of the variances in halo concentration, axis ratio, and spin, respectively, can be explained by combining four dominating predictors: the first PC of the assembly history, halo mass, and two environment parameters. Halo concentration is dominated by halo assembly. The local environment is found to be important for the axis ratio and spin but is degenerate with halo assembly. The small percentages of the variance in the axis ratio and spin that are explained by known assembly and environmental factors suggest that the variance is produced by many nuanced factors and should be modeled as such. The relations between halo intrinsic properties and environment are weak compared to their variances, with the anisotropy of the local tidal field having the strongest correlation with halo properties. Our method of dimension reduction and regression can help simplify the characterization of the halo population and clarify the degeneracy among halo properties.
A small nonaxisymmetric (3D) magnetic field can induce nonambipolar transport of the particle species confined in a tokamak and thus a significant change of plasma rotation. This process can be in a ...favor of instability control in the region where the tokamak plasma is sufficiently collisional and resistive, as observed in the applications of n=1 resonant magnetic perturbations to the KSTAR tokamak. The plasma rotation can be globally accelerated due to radially drifting electrons and constrained to the electron root, if the radial transport is enhanced by an amplified 3D response. This mechanism is verified by a kinetically self-consistent magnetohydrodynamic modeling for both response and transport, which offers the quantitative explanations on the internal n=1 structure detected by electron-cyclotron-emission imaging and the cocurrent plasma spinning observed in the experiments.
Large-scale hydrophilic Fe3O4 nanoparticles (NPs) were prepared in the presence of citrate and sodium nitrate via a facile method. The Fe3O4 NPs are quite stable and can be freely dispersed in water. ...The as-prepared magnetic nanoparticle solution can be stable for more than 1 month. The mean diameter of the Fe3O4 NPs can be controlled in the range of ∼20 to ∼40 nm in mean diameter. The NPs show superparamagnetic properties with a relatively high saturation magnetization moment 58 emu/mg at room temperature. Furthermore, a possible formation mechanism is proposed to explain why the magnetic nanoparticles are very well soluble in water.
The precipitations in an Al–5.0Cu–0.3Mg (wt%) alloy and an Al–5.0Cu–0.3Mg–0.3Si (wt%) alloy have been systematically investigated by high-angle annular dark-field scanning transmission electron ...microscopy. The results are compared to clarify the effect of Si addition. The nucleation and growth process of θ′ (Al2Cu) phase in Si-containing alloy during isothermal ageing at 180°C is revealed in detail. The formation of Q″-type precipitates, on which the θ′ precursors nucleate heterogeneously, contributes to the considerable increase in the ageing kinetics and higher strength at the early ageing stage. The thickening of the θ′ precipitate is largely confined due to the rather small size of fine Q″-type precipitate. As a result, a large proportion of θ′ phase precipitates possess a specific thickness of 2cθ′ and change slightly during the entire observed duration of ageing. The θ′ growth mechanism distinct from the Al–Cu–Mg alloy finally leads to a refined θ′ morphology regarding the thickness and aspect ratio (diameter/thickness). As is counterintuitive, the θ′ precipitate thickness distribution is demonstrated to have little effect on the mechanical property steadiness at the late ageing stage of the Al–Cu–Mg–(Si) alloys.
Eu-doped ZnO nanosheets-based microflowers have been synthesized successfully by using a hydrothermal method. Eu
3+-related red emission results from energy transfer are observed in the microflowers ...under UV laser excitation. Further systematic photoluminescence studies on the samples upon oxygen and vacuum annealing treatments suggest that there exists a strong correlation between the intrinsic defects and the efficiency of the Eu
3+-related emission. It is demonstrated that these defects may act as the media in the energy transfer process from the ZnO host to Eu
3+ ions.
Four isonitrogenous and isolipidic diets containing fresh fish oil (peroxide value, POV: 11.5 meq kg−1, diet FR) and three degrees of oxidized fish oil (POV: 132, 277 and 555 meq kg−1, diet OX132, ...OX277 and OX555, respectively) were formulated to investigate the effects of dietary oxidized fish oil on growth performance, body composition, antioxidant defence mechanism and liver histology of juvenile largemouth bass. After a 12‐week feeding trail, a proportion of approximately 9% of Micropterus salmoides showed inflammation and haemorrhage at the base of dorsal, pectoral and tail fin in both groups OX277 and OX555. Fish fed oxidized oil diets obtained significantly higher (P < 0.05) weight gain and specific growth rate because of their remarkable higher feed intakes, compared with the fresh oil receiving group. The analysis of biometric parameters and body composition indicated significant differences (P < 0.05) in various test diets. The activities of hepatic catalase and superoxide dismutase were significantly stimulated (P < 0.05) by oxidized oil ingestion. Hepatic glutathione peroxidase, glutathione reductase and glutathione‐S‐transferase activities were significantly higher (P < 0.05), and liver glutathione content was markedly lower (P < 0.05) in group OX555 than the other treatments. Oxidized oil consumption resulted in marked depletion (P < 0.05) of vitamin E concentration in plasma, liver and muscle tissue, increased plasma and muscle malondialdehyde content along with decreased haematocrit value. Histological examinations indicated that hepatocytes with lipid vacuoles and nuclear migration were shown in groups OX277 and OX555. The overall results in this study suggested that an increased oxidative stress in M. salmoides fed oxidized lipid may account for their stimulated hepatic antioxidant defences, vitamin E depletion in plasma and certain tissues, and pathological changes. The detrimental effect of oxidation products on fish health and the unexpectedly enhanced feed intake of oxidized feeds in M. salmoides underline the importance that cares should be taken to minimize dietary oxidation products to the greatest extent possible.
Epidermal growth factor (EGF) has been considered a potential regulator of meiotic and cytoplasmic maturation in mammalian oocytes, but inconsistencies exist between earlier studies, probably due to ...differences in the culture conditions used. Using a serum- and hormone-free in vitro maturation (IVM) medium, this study investigated the specific contribution of EGF on IVM of porcine (Sus scrofa) oocytes and its interactive effects with follicle-stimulating hormone (FSH), porcine follicular fluid (pFF), cumulus cells, and serum. It was noteworthy that EGF functionally mimicked the action of FSH and could completely replace FSH for nuclear maturation (83.2
±
4.4% vs. 55.9
±
5.2%; mean
±
SEM), whereas EGF had a synergistic effect with FSH on cytoplasmic maturation of porcine oocytes (P
<
0.05). Specific inhibition of EGF receptor (EGFR) by tyrphostin AG 1478 inhibited both EGF- and FSH-induced meiotic resumption (17.9
±
5.2% and 18.2
±
4.4%, respectively), thereby suggesting that EGFR signaling pathway was essential for oocyte reentry into the meiotic cell cycle. Furthermore, it is possible that FSH action occurs via the EGFR signaling pathway to induce meiotic maturation, although alternate pathways could not be excluded. There were also individual or combined effects of cumulus cells, FSH, serum, and pFF with EGF on IVM of porcine oocytes (P
<
0.05). Although FSH had a synergistic effect with EGF on cytoplasmic maturation, pFF masked the effects of EGF on both nuclear and cytoplasmic maturation of porcine oocytes (P
<
0.05). Moreover, the presence of cumulus cells was essential for EGF action. In conclusion, a defined system was used to better examine the effects of EGF. We inferred that EGF functionally mimics FSH for nuclear maturation of porcine oocytes, and its exogenous supplementation into IVM medium can optimize the beneficial effects of FSH on cytoplasmic maturation of oocytes to obtain enhanced embryo development in vitro.
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