381 research outputs found

    Neutron diffraction study of yttrium α'-sialon

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    The structure of yttrium a'-Sialon ceramic of compn. Y0.5Si9.75Al2.25N15.25O0.75 was examd. by powd. neutron diffraction and Rietfeld refinement of the data. [on SciFinder (R)

    Tumour necrosis factor-α up-regulates macrophage migration inhibitory factor expression in endometrial stromal cells via the nuclear transcription factor NF-ÎșB

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    BACKGROUND: A series of controlled changes including proliferation, secretion and menstrual shedding occur in the human endometrium during every normal menstrual cycle. Macrophage migration inhibitory factor (MIF), a multifunctional cytokine with numerous proinflammatory, immunomodulatory and angiogenic properties, appears to be expressed in the human endometrium and to follow a regulated cycle phase-dependent expression, but the mechanisms underlying endometrial MIF expression remain to be fully elucidated. METHODS AND RESULTS: Results from enzyme-linked immunosorbent assay (ELISA) demonstrated a significant dose- and time-dependent increase in MIF secretion by human endometrial cells in response to tumour necrosis factor-alpha (TNF-α) (0.1-100 ng/ml). This increase was also observed at the mRNA level as shown by reverse transcription (RT)-PCR. Curcumin (10−8 mol/l), a known nuclear factor (NF)-ÎșB inhibitor, inhibited the TNF-α-induced pIÎșB phosphorylation as shown by western blotting, NF-ÎșB translocation into the nucleus as shown by electrophoretic mobility shift assay, and MIF synthesis and secretion as measured by ELISA and RT-PCR. The expression of a dominant-negative NF-ÎșB inhibitor (IÎșB) significantly decreased the TNF-α-induced MIF promoter activity as analysed by transient cell transfection. CONCLUSIONS: These results indicate clearly that TNF-α up-regulates the expression of MIF in endometrial stromal cells. This took place possibly through NF-ÎșB activation, and may play an important role in the physiology of the human endometriu

    Mitochondrial permeabilization engages NF-ÎșB-dependent anti-tumour activity under caspase deficiency

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    Apoptosis represents a key anti-cancer therapeutic effector mechanism. During apoptosis, mitochondrial outer membrane permeabilization (MOMP) typically kills cells even in the absence of caspase activity. Caspase activity can also have a variety of unwanted consequences that include DNA damage. We therefore investigated whether MOMP-induced caspase-independent cell death (CICD) might be a better way to kill cancer cells. We find that cells undergoing CICD display potent pro-inflammatory effects relative to apoptosis. Underlying this, MOMP was found to stimulate NF-ÎșB activity through the downregulation of inhibitor of apoptosis proteins. Strikingly, engagement of CICD displays potent anti-tumorigenic effects, often promoting complete tumour regression in a manner dependent on intact immunity. Our data demonstrate that by activating NF-ÎșB, MOMP can exert additional signalling functions besides triggering cell death. Moreover, they support a rationale for engaging caspase-independent cell death in cell-killing anti-cancer therapies

    Stress-induced TRAILR2 expression overcomes TRAIL resistance in cancer cell spheroids

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    The influence of 3D microenvironments on apoptosis susceptibility remains poorly understood. Here, we studied the susceptibility of cancer cell spheroids, grown to the size of micrometastases, to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Interestingly, pronounced, spatially coordinated response heterogeneities manifest within spheroidal microenvironments: In spheroids grown from genetically identical cells, TRAIL-resistant subpopulations enclose, and protect TRAIL-hypersensitive cells, thereby increasing overall treatment resistance. TRAIL-resistant layers form at the interface of proliferating and quiescent cells and lack both TRAILR1 and TRAILR2 protein expression. In contrast, oxygen, and nutrient deprivation promote high amounts of TRAILR2 expression in TRAIL-hypersensitive cells in inner spheroid layers. COX-II inhibitor celecoxib further enhanced TRAILR2 expression in spheroids, likely resulting from increased ER stress, and thereby re-sensitized TRAIL-resistant cell layers to treatment. Our analyses explain how TRAIL response heterogeneities manifest within well-defined multicellular environments, and how spatial barriers of TRAIL resistance can be minimized and eliminated

    Two-dimensional wave radiation and diffraction problems in a flat or sloping seabed environment

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    Two-dimensional water wave problems are investigated in an environment with a flat or sloping rigid seabed adopting a continuous Rankine source method. All the fluid domain surfaces, that is the free, body and seabed surfaces, are discretized using continuous panels. These panels are positioned exactly on the fluid boundary surfaces and no desingularization technique is required. A new seabed source panel distribution method is developed to accommodate both symmetric and asymmetric seabed profiles. To validate the numerical model comparisons are made with published findings from other mathematical models and experimental data. The presence of a sloped seabed alters the symmetry of the fluid domain, causing wave reflection and shoaling, and therefore, significantly affects the hydrodynamic characteristics of water wave problems. The influence of these topographies on the responses in all three degrees of freedom (heave, sway and roll) of a rigid floating body are investigated and discussed accounting for wave radiation and diffraction problems

    Driver Fusions and Their Implications in the Development and Treatment of Human Cancers.

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    Gene fusions represent an important class of somatic alterations in cancer. We systematically investigated fusions in 9,624 tumors across 33 cancer types using multiple fusion calling tools. We identified a total of 25,664 fusions, with a 63% validation rate. Integration of gene expression, copy number, and fusion annotation data revealed that fusions involving oncogenes tend to exhibit increased expression, whereas fusions involving tumor suppressors have the opposite effect. For fusions involving kinases, we found 1,275 with an intact kinase domain, the proportion of which varied significantly across cancer types. Our study suggests that fusions drive the development of 16.5% of cancer cases and function as the sole driver in more than 1% of them. Finally, we identified druggable fusions involving genes such as TMPRSS2, RET, FGFR3, ALK, and ESR1 in 6.0% of cases, and we predicted immunogenic peptides, suggesting that fusions may provide leads for targeted drug and immune therapy

    Measurement of the cross section of high transverse momentum Z→bb̄ production in proton–proton collisions at √s = 8 TeV with the ATLAS detector

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    This Letter reports the observation of a high transverse momentum Z→bb̄ signal in proton–proton collisions at √s=8 TeV and the measurement of its production cross section. The data analysed were collected in 2012 with the ATLAS detector at the LHC and correspond to an integrated luminosity of 19.5 fb−Âč. The Z→bb̄ decay is reconstructed from a pair of b -tagged jets, clustered with the anti-ktkt jet algorithm with R=0.4R=0.4, that have low angular separation and form a dijet with pT>200 GeVpT>200 GeV. The signal yield is extracted from a fit to the dijet invariant mass distribution, with the dominant, multi-jet background mass shape estimated by employing a fully data-driven technique that reduces the dependence of the analysis on simulation. The fiducial cross section is determined to be σZ→bbÂŻfid=2.02±0.20 (stat.) ±0.25 (syst.)±0.06 (lumi.) pb=2.02±0.33 pb, in good agreement with next-to-leading-order theoretical predictions

    Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

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    We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society
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