2,418 research outputs found

    Atomic and Molecular Absorption in Redshifted Radio Sources

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    We report on a survey for associated HI 21-cm and OH 18-cm absorption with the Giant Metrewave Radio Telescope at redshifts z = 0.2-0.4. Although the low redshift selection ensures that our targets are below the critical ultra-violet luminosity, which is hypothesised to ionise all of the neutral gas in the host galaxy, we do not obtain any detections in the six sources searched. Analysing these in context of the previous surveys, in addition to the anti-correlation with the ultra-violet luminosity (ionising photon rate), we find a correlation between the strength of the absorption and the blue -- near-infrared colour, as well as the radio-band turnover frequency. We believe that these are due to the photo-ionisation of the neutral gas, an obscured sight-line being more conducive to the presence of cold gas and the compact radio emission being better intercepted by the absorbing gas, maximising the flux coverage, respectively. Regarding the photo-ionisation, the compilation of the previous surveys increases the significance of the critical ionising photon rate, above which all of the gas in the host galaxy is hypothesised to be ionised, to >5 sigma. This reaffirms that this is an ubiquitous effect, which has profound implications for the detection of neutral gas in these objects with the Square Kilometre Array.Comment: Accepted by MNRA

    PKSB1740-517: An ALMA view of the cold gas feeding a distant interacting young radio galaxy

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    Cold neutral gas is a key ingredient for growing the stellar and central black hole mass in galaxies throughout cosmic history. We have used the Atacama Large Millimetre Array (ALMA) to detect a rare example of redshifted 12^{12}CO(2-1) absorption in PKS B1740-517, a young (t1.6×103t \sim 1.6 \times 10^{3} yr) and luminous (L5GHz6.6×1043L_{\rm 5 GHz} \sim 6.6 \times 10^{43} erg s1^{-1} ) radio galaxy at z=0.44z = 0.44 that is undergoing a tidal interaction with at least one lower-mass companion. The coincident HI 21-cm and molecular absorption have very similar line profiles and reveal a reservoir of cold gas (Mgas107108M_{\rm gas} \sim 10^{7} - 10^{8} M_{\odot}), likely distributed in a disc or ring within a few kiloparsecs of the nucleus. A separate HI component is kinematically distinct and has a very narrow line width (ΔvFWHM5\Delta{v}_{\rm FWHM} \lesssim 5 km s1^{-1}), consistent with a single diffuse cloud of cold (Tk100T_{\rm k} \sim 100 K) atomic gas. The 12^{12}CO(2-1) absorption is not associated with this component, which suggests that the cloud is either much smaller than 100 pc along our sight-line and/or located in low-metallicity gas that was possibly tidally stripped from the companion. We argue that the gas reservoir in PKS B1740-517 may have accreted onto the host galaxy \sim50 Myr before the young radio AGN was triggered, but has only recently reached the nucleus. This is consistent with the paradigm that powerful luminous radio galaxies are triggered by minor mergers and interactions with low-mass satellites and represent a brief, possibly recurrent, active phase in the life cycle of massive early type galaxies.Comment: 15 pages, 7 figures, accepted for publication in MNRA

    Screen for DNA-damage-responsive histone modifications identifies H3K9Ac and H3K56Ac in human cells

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    Recognition and repair of damaged DNA occurs within the context of chromatin. The key protein components of chromatin are histones, whose post-translational modifications control diverse chromatin functions. Here, we report our findings from a large-scale screen for DNA-damage-responsive histone modifications in human cells. We have identified specific phosphorylations and acetylations on histone H3 that decrease in response to DNA damage. Significantly, we find that DNA-damage-induced changes in H3S10p, H3S28p and H3.3S31p are a consequence of cell-cycle re-positioning rather than DNA damage per se. In contrast, H3K9Ac and H3K56Ac, a mark previously uncharacterized in human cells, are rapidly and reversibly reduced in response to DNA damage. Finally, we show that the histone acetyl-transferase GCN5/KAT2A acetylates H3K56 in vitro and in vivo. Collectively, our data indicate that though most histone modifications do not change appreciably after genotoxic stress, H3K9Ac and H3K56Ac are reduced in response to DNA damage in human cells

    The Warburg effect as a therapeutic target for bladder cancers and intratumoral heterogeneity in associated molecular targets

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    Bladder cancer is the 10th most common cancer worldwide. For muscle-invasive bladder cancer (MIBC), treatment includes radical cystectomy, radiotherapy, and chemotherapy; however, the outcome is generally poor. For non–muscle-invasive bladder cancer (NMIBC), tumor recurrence is common. There is an urgent need for more effective and less harmful therapeutic approaches. Here, bladder cancer cell metabolic reprogramming to rely on aerobic glycolysis (the Warburg effect) and expression of associated molecular therapeutic targets by bladder cancer cells of different stages and grades, and in freshly resected clinical tissue, is investigated. Importantly, analyses indicate that the Warburg effect is a feature of both NMIBCs and MIBCs. In two in vitro inducible epithelial-mesenchymal transition (EMT) bladder cancer models, EMT stimulation correlated with increased lactate production, the end product of aerobic glycolysis. Protein levels of lactate dehydrogenase A (LDH-A), which promotes pyruvate enzymatic reduction to lactate, were higher in most bladder cancer cell lines (compared with LDH-B, which catalyzes the reverse reaction), but the levels did not closely correlate with aerobic glycolysis rates. Although LDH-A is expressed in normal urothelial cells, LDH-A knockdown by RNAi selectively induced urothelial cancer cell apoptotic death, whereas normal cells were unaffected—identifying LDH-A as a cancer-selective therapeutic target for bladder cancers. LDH-A and other potential therapeutic targets (MCT4 and GLUT1) were expressed in patient clinical specimens; however, positive staining varied in different areas of sections and with distance from a blood vessel. This intratumoral heterogeneity has important therapeutic implications and indicates the possibility of tumor cell metabolic coupling

    The effect of water immersion on short-latency somatosensory evoked potentials in human

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    <p>Abstract</p> <p>Background</p> <p>Water immersion therapy is used to treat a variety of cardiovascular, respiratory, and orthopedic conditions. It can also benefit some neurological patients, although little is known about the effects of water immersion on neural activity, including somatosensory processing. To this end, we examined the effect of water immersion on short-latency somatosensory evoked potentials (SEPs) elicited by median nerve stimuli. Short-latency SEP recordings were obtained for ten healthy male volunteers at rest in or out of water at 30°C. Recordings were obtained from nine scalp electrodes according to the 10-20 system. The right median nerve at the wrist was electrically stimulated with the stimulus duration of 0.2 ms at 3 Hz. The intensity of the stimulus was fixed at approximately three times the sensory threshold.</p> <p>Results</p> <p>Water immersion significantly reduced the amplitudes of the short-latency SEP components P25 and P45 measured from electrodes over the parietal region and the P45 measured by central region.</p> <p>Conclusions</p> <p>Water immersion reduced short-latency SEP components known to originate in several cortical areas. Attenuation of short-latency SEPs suggests that water immersion influences the cortical processing of somatosensory inputs. Modulation of cortical processing may contribute to the beneficial effects of aquatic therapy.</p> <p>Trial Registration</p> <p>UMIN-CTR (UMIN000006492)</p

    Are autistic traits measured equivalently in individuals with and without an Autism Spectrum Disorder?:An invariance analysis of the Autism Spectrum Quotient Short Form

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    It is common to administer measures of autistic traits to those without autism spectrum disorders (ASDs) with, for example, the aim of understanding autistic personality characteristics in non-autistic individuals. Little research has examined the extent to which measures of autistic traits actually measure the same traits in the same way across those with and without an ASD. We addressed this question using a multi-group confirmatory factor invariance analysis of the Autism Quotient Short Form (AQ-S: Hoekstra et al. in J Autism Dev Disord 41(5):589-596, 2011) across those with (n = 148) and without (n = 168) ASD. Metric variance (equality of factor loadings), but not scalar invariance (equality of thresholds), held suggesting that the AQ-S measures the same latent traits in both groups, but with a bias in the manner in which trait levels are estimated. We, therefore, argue that the AQ-S can be used to investigate possible causes and consequences of autistic traits in both groups separately, but caution is due when combining or comparing levels of autistic traits across the two group

    Site-specific incorporation of phosphotyrosine using an expanded genetic code.

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    Access to phosphoproteins with stoichiometric and site-specific phosphorylation status is key to understanding the role of protein phosphorylation. Here we report an efficient method to generate pure, active phosphotyrosine-containing proteins by genetically encoding a stable phosphotyrosine analog that is convertible to native phosphotyrosine. We demonstrate its general compatibility with proteins of various sizes, phosphotyrosine sites and functions, and reveal a possible role of tyrosine phosphorylation in negative regulation of ubiquitination

    In-Vivo Biodistribution and Safety of 99mTc-LLP2A-HYNIC in Canine Non-Hodgkin Lymphoma

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    Theranostic agents are critical for improving the diagnosis and treatment of non-Hodgkin Lymphoma (NHL). The peptidomimetic LLP2A is a novel peptide receptor radiotherapy candidate for treating NHL that expresses the activated α4β1 integrin. Tumor-bearing dogs are an excellent model of human NHL with similar clinical characteristics, behavior, and compressed clinical course. Canine in vivo imaging studies will provide valuable biodistribution and affinity information that reflects a diverse clinical population of lymphoma. This may also help to determine potential dose-limiting radiotoxicity to organs in human clinical trials. To validate this construct in a naturally occurring model of NHL, we performed in-vivo molecular targeted imaging and biodistribution in 3 normal dogs and 5 NHL bearing dogs. 99mTc-LLP2A-HYNIC-PEG and 99mTc-LLP2A-HYNIC were successfully synthesized and had very good labeling efficiency and radiochemical purity. 99mTc-LLP2A-HYNIC and 99mTc-LLP2A-HYNIC-PEG had biodistribution in keeping with their molecular size, with 99mTc-LLP2A-HYNIC-PEG remaining longer in the circulation, having higher tissue uptake, and having more activity in the liver compared to 99mTc-LLP2A-HYNIC. 99mTc-LLP2A-HYNIC was mainly eliminated through the kidneys with some residual activity. Radioactivity was reduced to near-background levels at 6 hours after injection. In NHL dogs, tumor showed moderately increased activity over background, with tumor activity in B-cell lymphoma dogs decreasing after chemotherapy. This compound is promising in the development of targeted drug-delivery radiopharmaceuticals and may contribute to translational work in people affected by non-Hodgkin lymphoma
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