1,445 research outputs found

    Neurofibromin knockdown in glioma cell lines is associated with changes in cytokine and chemokine secretion in vitro.

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    The neurofibromin-1 tumor suppressor gene (NF1) is altered in approximately 20% of sporadic glioblastoma (GBM) cases. NF1 deficient GBM frequently shows a mesenchymal gene expression signature, suggesting a relationship between NF1 status and the tumor microenvironment. To identify changes in the production of secreted cytokines/chemokines in NF1 deficient glioma, we applied cytokine arrays to conditioned media from a panel of three GBM cell lines after siRNA-mediated NF1 knockdown. We identified increased secretion of platelet-derived growth factor AA (PDGF-AA), chitinase-3-like protein 1 (CHI3L1), interleukin-8 (IL-8), and endoglin (ENG) in different subsets of these cell lines. Secretion was associated with induction of the corresponding messenger RNA, suggesting a mechanism involving transcriptional upregulation. By contrast, in non-transformed immortalized normal human astrocytes, PDGF-AA secretion was increased upon NF1 knockdown, while secreted CHI3L1, ENG, and IL-8 were reduced or unchanged. Analysis of The Cancer Genome Atlas confirmed a relationship between glioma NF1 status and ENG and CHI3L1 in tumor samples. Overall, this study identifies candidate changes in secreted proteins from NF1 deficient glioma cells that could influence the tumor microenvironment, and suggests a direct link between NF1 loss and increased tumor cell production of CHI3L1 and endoglin, two factors implicated in mesenchymal identity in glioblastoma

    Solar Protons and Magnetic Storms in July 1961

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    Injun i satellite observations of solar protons and magnetic storm

    Ab initio calculation of the electromagnetic and neutral-weak response functions of 4He and 12C

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    Precise measurement of neutrino oscillations, and hence the determination of their masses demands a quantitative understanding of neutrino-nucleus interactions. To this aim, two-body meson-exchange currents have to be accounted for along within realistic models of nuclear dynamics. We summarize our progresses towards the construction of a consistent framework, based on quantum Monte Carlo methods and on the spectral function approach, that can be exploited to accurately describe neutrino interactions with atomic nuclei over the broad kinematical region covered by neutrino experiments.Comment: 8 pages, 4 figure, Proceedings of the 21st International Conference on Few-Body Problems in Physics, Chicago, Illinois, US

    Auswahl generativer prozessketten für die herstellung metallischer endprodukte

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    The application of generating processes for the creation of metal end-products can only be applied economically with small batch size and geometrically high-complex workpieces. This paper concerns the analytic evaluation of several additive methods and its process chains and compares these with traditional manufacturing technologies regarding the quality, processing time, expenses as well as the complexity of the product. The existing methods of process planning and the assurance of the quality are extended with a focus on the new manufacturing possibilities which can be realized by the application of additive processes.У даній статті розглядаються питання аналітичної оцінки процесу селективного спікання і його технологічних ланцюжків у порівнянні із традиційними технологіями виробництва. Критеріями порівняння є якість, час обробки, витрати, а також складність геометрії виробу. Існуючі методи планування й забезпечення якості повинні бути доповнені з урахуванням нових можливостей виготовлення виробів, які відкривають генеративні методи. Застосування генеративних технологій для виготовлення металевих кінцевих продуктів економічно обґрунтовано тільки для деталей зі складною геометрією й малим розміром

    Failure of Intravenous Morphine to Serve as an Effective Instrumental Reinforcer in Dopamine D2 Receptor Knock-Out Mice

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    The rewarding effects of opiates are thought to be mediated through dopaminergic mechanisms in the ventral tegmental area, dopamine-independent mechanisms in the nucleus accumbens, or both. The purpose of the present study was to explore the contribution of dopamine to opiate-reinforced behavior using D2 receptor knock-out mice. Wild-type, heterozygous, and D2 knock-out mice were first trained to lever press for water reinforcement and then implanted with intravenous catheters. The ability of intravenously delivered morphine to maintain lever pressing in these mice was studied under two schedules of reinforcement: a fixed ratio 4 (FR4) schedule (saline, 0.1, 0.3, or 1.0 mg/kg, per injection) and a progressive ratio (PR) schedule (1.0 mg/kg, per injection). In the wild-type and heterozygous mice, FR4 behavior maintained by morphine injections was significantly greater than behavior maintained by vehicle injections. Response rate was inversely related to injection dose and increased significantly in the wild-type and heterozygous mice when the animals were placed on the PR schedule. In contrast, the knock-out mice did not respond more for morphine than for saline and did not respond more when increased ratios were required by the PR schedule. Thus, morphine served as a positive reinforcer in the wild-type and heterozygous mice but failed to do so in the knock-out mice. Under this range of doses and response requirements, the rewarding effects of morphine appear to depend critically on an intact D2 receptor systemFil: Elmer, Greg I.. University of Maryland; Estados UnidosFil: Pieper, Jeanne O.. National Institutes of Health; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Low, Malcolm J.. Oregon Health and Sciences University; Estados UnidosFil: Grandy, David K.. Oregon Health and Sciences University; Estados UnidosFil: Wise, Roy A.. National Institutes of Health; Estados Unido

    Evaluating benthic macroinvertebrate populations in response to scouring events in the Trinity River, CA

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    River systems across California have been impacted by appurtenant structures such as dams and diversions. These structures have had an adverse impact on Benthic invertebrate (BMI) communities by regulating river systems and changing the natural hydraulic pulses that follow seasonal precipitation. Benthic invertebrates are a critical food resource for salmonids and serve as an indicator of ecosystem health. Our study was interested in seeing the effects of scouring events on BMI in the Trinity River of Trinity County, C.A. Following a large precipitation event that occurred in the region in December 2022, an influx of water entered the river through flood releases from Lewiston Dam, natural storm runoff, and accretion from regional tributaries along the Trinity River. The BMI samples from the Pear Tree Gulch site were used to measure the effects of the scouring event that occurred between January 8 and January 14, 2023. Our results showed that the Shannon Diversity Index (SDI) increased after the scouring event, the composition changed, and overall abundance decreased after the scour event. This study suggests that an isolated period of scouring in a regulated system does not result in BMI metrics associated with unregulated systems that experience frequent scouring events

    Yukawa model on a lattice: two body states

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    We present first results of the solutions of the Yukawa model as a Quantum Field Theory (QFT) solved non perturbatively with the help of lattice calculations. In particular we will focus on the possibility of binding two nucleons in the QFT, compared to the non relativistic result.Comment: 3 pages, talk at "IVth International Conference on Quarks and Nuclear Physics" (Madrid, June 2006

    Many-body effects in 16O(e,e'p)

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    Effects of nucleon-nucleon correlations on exclusive (e,ep)(e,e'p) reactions on closed-shell nuclei leading to single-hole states are studied using 16O(e,ep)15N^{16}O(e,e'p)^{15}N (6.326.32 MeV, 3/23/2^-) as an example. The quasi-hole wave function, calculated from the overlap of translationally invariant many-body variational wave functions containing realistic spatial, spin and isospin correlations, seems to describe the initial state of the struck proton accurately inside the nucleus, however it is too large at the surface. The effect of short-range correlations on the final state is found to be largely cancelled by the increase in the transparency for the struck proton. It is estimated that the values of the spectroscopic factors obtained with the DWIA may increase by a few percent due to correlation effects in the final state.Comment: 21 Pages, PHY-7849-TH-9
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