765 research outputs found

    Molecular gas in nearby powerful radio galaxies

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    We report the detection of CO(1-0) and CO(2-1) emission from the central region of nearby 3CR radio galaxies (z<< 0.03). Out of 21 galaxies, 8 have been detected in, at least, one of the two CO transitions. The total molecular gas content is below 109^9 \msun. Their individual CO emission exhibit, for 5 cases, a double-horned line profile that is characteristic of an inclined rotating disk with a central depression at the rising part of its rotation curve. The inferred disk or ring distributions of the molecular gas is consistent with the observed presence of dust disks or rings detected optically in the cores of the galaxies. We reason that if their gas originates from the mergers of two gas-rich disk galaxies, as has been invoked to explain the molecular gas in other radio galaxies, then these galaxies must have merged a long time ago (few Gyr or more) but their remnant elliptical galaxies only recently (last 107^7 years or less) become active radio galaxies. Instead, we argue the the cannibalism of gas-rich galaxies provide a simpler explanation for the origin of molecular gas in the elliptical hosts of radio galaxies (Lim et al. 2000). Given the transient nature of their observed disturbances, these galaxies probably become active in radio soon after the accretion event when sufficient molecular gas agglomerates in their nuclei.Comment: 6 pages, including 2 figures,in "QSO Hosts and Their Environments", ed. I. Marquez, in pres

    Synergistic Impact of Alpha-Fetoprotein and Tumor Burden on Long-Term Outcomes Following Curative-Intent Resection of Hepatocellular Carcinoma

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    Introduction: The prognostic role of tumor burden score (TBS) relative to pre-operative α -fetoprotein (AFP) levels among patients undergoing curative-intent resection of HCC has not been examined. Methods: Patients who underwent curative-intent resection of HCC between 2000 and 2017 were identified from a multi-institutional database. The impact of TBS on overall survival (OS) and cumulative recurrence relative to serum AFP levels was assessed. Results: Among 898 patients, 233 (25.9%) patients had low TBS, 572 (63.7%) had medium TBS and 93 (10.4%) had high TBS. Both TBS (5-year OS; low TBS: 76.9%, medium TBS: 60.9%, high TBS: 39.1%) and AFP (>400 ng/mL vs. <400 ng/mL: 48.5% vs. 66.1%) were strong predictors of outcomes (both p < 0.001). Lower TBS was associated with better OS among patients with both low (5-year OS, low-medium TBS: 68.0% vs. high TBS: 47.7%, p < 0.001) and high AFP levels (5-year OS, low-medium TBS: 53.7% vs. high TBS: not reached, p < 0.001). Patients with low-medium TBS/high AFP had worse OS compared with individuals with low-medium TBS/low AFP (5-year OS, 53.7% vs. 68.0%, p = 0.003). Similarly, patients with high TBS/high AFP had worse outcomes compared with patients with high TBS/low AFP (5-year OS, not reached vs. 47.7%, p = 0.015). Patients with high TBS/low AFP and low TBS/high AFP had comparable outcomes (5-year OS, 47.7% vs. 53.7%, p = 0.24). The positive predictive value of certain TBS groups relative to the risk of early recurrence and 5-year mortality after HCC resection increased with higher AFP levels. Conclusion: Both TBS and serum AFP were important predictors of prognosis among patients with resectable HCC. Serum AFP and TBS had a synergistic impact on prognosis following HCC resection with higher serum AFP predicting worse outcomes among patients with HCC of a certain TBS class.info:eu-repo/semantics/publishedVersio

    Serum α-Fetoprotein Levels at Time of Recurrence Predict Post-Recurrence Outcomes Following Resection of Hepatocellular Carcinoma

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    Introduction: Although preoperative α-fetoprotein (AFP) has been recognized as an important tumor marker among patients with hepatocellular carcinoma (HCC), the predictive value of AFP levels at the time of recurrence (rAFP) on post-recurrence outcomes has not been well examined. Methods: Patients undergoing curative-intent resection of HCC between 2000 and 2017 were identified using a multi-institutional database. The impact of rAFP on post-recurrence survival, as well as the impact of rAFP relative to the timing and treatment of HCC recurrence were examined. Results: Among 852 patients who underwent resection of HCC, 307 (36.0%) individuals developed a recurrence. The median rAFP level was 8 ng/mL (interquartile range 3-100). Among the 307 patients who developed recurrence, 3-year post-recurrence survival was 48.5%. Patients with rAFP > 10 ng/mL had worse 3-year post-recurrence survival compared with individuals with rAFP 10 vs. 10 vs. 10 ng/mL had a twofold higher hazard of death in the post-recurrence setting (hazard ratio 1.96, 95% confidence interval 1.26-3.04). Conclusion: AFP levels at the time of recurrence following resection of HCC predicted post-recurrence survival independent of the secondary treatment modality used. Evaluating AFP levels at the time of recurrence can help inform post-recurrence risk stratification of patients with recurrent HCC.info:eu-repo/semantics/publishedVersio

    Is Our Universe Natural?

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    It goes without saying that we are stuck with the universe we have. Nevertheless, we would like to go beyond simply describing our observed universe, and try to understand why it is that way rather than some other way. Physicists and cosmologists have been exploring increasingly ambitious ideas that attempt to explain why certain features of our universe aren't as surprising as they might first appear.Comment: Invited review for Nature, 11 page

    Self-healing capacity of nuclear glass observed by NMR spectroscopy

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    Safe management of high level nuclear waste is a worldwide significant issue for which vitrification has been selected by many countries. There exists a crucial need for improving our understanding of the ageing of the glass under irradiation. While external irradiation by ions provides a rapid simulation of damage induced by alpha decays, short lived actinide doping is more representative of the reality. Here, we report radiological NMR experiments to compare the damage in International Simplified Glass (ISG) when irradiated by these two methods. In the 0.1 mole percent 244Cm doped glass, accumulation of high alpha decay only shows small modifications of the local structure, in sharp contrast to heavy ion irradiation. These results reveal the ability of the alpha particle to partially repair the damage generated by the heavy recoil nuclei highlighting the radiation resistance of nuclear glass and the difficulty to accurately simulate its behaviour by single ion beam irradiations

    Impact of Tumor Burden Score on Conditional Survival after Curative-Intent Resection for Hepatocellular Carcinoma: A Multi-Institutional Analysis

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    Background: The impact of tumor burden score (TBS) on conditional survival (CS) among patients undergoing curative-intent resection of hepatocellular carcinoma (HCC) has not been examined to date. Methods: Patients who underwent liver resection of HCC between 2000 and 2017 were identified from a multi-institutional database. The impact of TBS and other clinicopathologic factors on 3-year conditional survival (CS3) was examined. Results: Among 1,040 patients, 263 (25.3%) patients had low TBS, 668 (64.2%) had medium TBS and 109 (10.5%) had high TBS. TBS was strongly associated with OS; 5-year OS was 39.0% among patients with high TBS compared with 61.1% and 79.4% among patients with medium and low TBS, respectively (p < 0.001). While actuarial survival decreased as time elapsed from resection, CS increased over time irrespective of TBS. The largest differences between 3-year actuarial survival and CS3 were noted among patients with high TBS (5-years postoperatively; CS3: 78.7% vs. 3-year actuarial survival: 30.7%). The effect of adverse clinicopathologic factors including high TBS, poor/undifferentiated tumor grade, microvascular invasion, liver capsule involvement, and positive margins on prognosis decreased over time. Conclusions: CS rates among patients who underwent resection for HCC increased as patients survived additional years, irrespective of TBS. CS estimates can be used to provide important dynamic information relative to the changing survival probability after resection of HCC.info:eu-repo/semantics/publishedVersio

    Impact of Body Mass Index on Tumor Recurrence Among Patients Undergoing Curative - Intent Resection of Intrahepatic Cholangiocarcinoma - a Multi-institutional International Analysis

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    Background: The association between body mass index (BMI) and long-term outcomes of patients with ICC has not been well defined. We sought to define the presentation and oncologic outcomes of patients with ICC undergoing curative-intent resection, according to their BMI category. Methods: Patients who underwent resection of ICC were identified in a multi-institutional database. Patients were categorized as normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2) and obese (BMI≥30 kg/m2) according to the World Health Organization (WHO) definition. Impact of clinico-pathological factors on recurrence-free survival (RFS) was assessed using Cox proportional hazards model among patients in the three BMI categories. Results: Among a total of 790 patients undergoing curative-intent resection of ICC in the analytic cohort, 399 (50.5%) had normal weight, 274 (34.7%) were overweight and 117 (14.8%) were obese. Caucasian patients were more likely to be obese (66.7%, n = 78) and overweight (47.1%, n = 129) compared with Asian (obese: 18.8%, n = 22; overweight: 46%, n = 126) and other races (obese: 14.5%, n = 17; overweight: 6.9%, n = 19)(p 0.05). On multivariable analysis, increased BMI was an independent risk factor for tumor recurrence (OR 1.16, 95% CI 1.02-1.32, for every 5 unit increase). Conclusion: Increasing BMI was associated with incremental increases in the risk of recurrence following curative-intent resection of ICC. Future studies should aim to achieve a better understanding of BMI-related factors relative to prognosis of patients with ICC.info:eu-repo/semantics/publishedVersio

    Mathematical modelling of cytokines, MMPs and fibronectin fragments in osteoarthritic cartilage

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    Osteoarthritis (OA) is a degenerative disease which causes pain and stiffness in joints. OA progresses through excessive degradation of joint cartilage, eventually leading to significant joint degeneration and loss of function. Cytokines, a group of cell signalling proteins, present in raised concentrations in OA joints, can be classified into pro-inflammatory and anti-inflammatory groups. They mediate cartilage degradation through several mechanisms, primarily the up-regulation of matrix metalloproteinases (MMPs), a group of collagen-degrading enzymes. In this paper we show that the interactions of cytokines within cartilage have a crucial role to play in OA progression and treatment. We develop a four-variable ordinary differential equation model for the interactions between pro- and anti-inflammatory cytokines, MMPs and fibronectin fragments (Fn-fs), a by-product of cartilage degradation and upregulator of cytokines. We show that the model has four classes of dynamic behaviour: homoeostasis, bistable inflammation, tristable inflammation and persistent inflammation. We show that positive and negative feedbacks controlling cytokine production rates can determine either a pre-disposition to OA or initiation of OA. Further, we show that manipulation of cytokine, MMP and Fn-fs levels can be used to treat OA, but we suggest that multiple treatment targets may be essential to halt or slow disease progression

    Infrared (810-nm) low-level laser therapy on rat experimental knee inflammation

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    Arthritis of the knee is the most common type of joint inflammatory disorder and it is associated with pain and inflammation of the joint capsule. Few studies address the effects of the 810-nm laser in such conditions. Here we investigated the effects of low-level laser therapy (LLLT; infrared, 810-nm) in experimentally induced rat knee inflammation. Thirty male Wistar rats (230–250 g) were anesthetized and injected with carrageenan by an intra-articular route. After 6 and 12 h, all animals were killed by CO2 inhalation and the articular cavity was washed for cellular and biochemical analysis. Articular tissue was carefully removed for real-time PCR analysis in order to evaluate COX-1 and COX-2 expression. LLLT was able to significantly inhibit the total number of leukocytes, as well as the myeloperoxidase activity with 1, 3, and 6 J (Joules) of energy. This result was corroborated by cell counting showing the reduction of polymorphonuclear cells at the inflammatory site. Vascular extravasation was significantly inhibited at the higher dose of energy of 10 J. Both COX-1 and 2 gene expression were significantly enhanced by laser irradiation while PGE2 production was inhibited. Low-level laser therapy operating at 810 nm markedly reduced inflammatory signs of inflammation but increased COX-1 and 2 gene expression. Further studies are necessary to investigate the possible production of antiinflammatory mediators by COX enzymes induced by laser irradiation in knee inflammation
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