271 research outputs found
Abstract 1880: Bulk lung cancer cell migration is more common than single cell migration and regulated by different genes
No full textAbstract
Introduction: There are two different forms how tumor cells migrate: single cell or small cell cluster movement as it is seen in small cell carcinoma, and movement by large clusters of organized cells as seen most often in adenocarcinoma or squamous cell carcinoma. This latter migration form is not understood. Drosophila border cells forming wings migrate in large cell complexes similar to what is seen in the carcinomas and the genes identified in these cells might regulate the same process in carcinomas. Methods: 30 cases of pulmonary squamous cell and adenocarcinomas were selected based on the identification of large tumor cell clusters visible within the stroma as well as in blood vessels. Immunohistochemistry was done for receptor of activated C kinase (Rack1), brinker (brk), mother against dpp (mad), and saxophone (sax), proteins shown to be responsible for bulk cell movement in drosophila development. In addition immunohistochemistry was also done for Src-kinase, Twist, Snail, and TGFβ1 Tyrosine kinase substrate 5 (Tks5), E-cadherin, SARI (suppressor of AP-1), and vimentin, all known to be associated with epithelial-to-mesenchymal transition (EMT) and formation of invadopodia. Results and Conclusion: Most well differentiated pulmonary carcinomas migrate in large cell clusters, for example acinar adenocarcinomas form nicely structured acini deep within the stroma and even within blood vessels. These carcinomas do not undergo classical EMT. Proteins expressed by the four genes (Rack1, brk, mad, and sax) associated with border cell movement in drosophila could also be identified in pulmonary carcinomas and might coordinate bulk cell movement. Other members of TGF-beta signaling cascade were identified. Inhibition of Src by Rack1 may be important for border cell migration and cluster cohesion maintenance. Proteins usually seen in single tumor cell migration, such as vimentin (a sign of EMT) could not be proven in the tumor cell clusters. Findings of this study show that similar mechanisms are working in pulmonary carcinomas and that bulk cell migration is probably another way of metastasis. Further investigation using cell culture system and genetically designed adenocarcinomas expressing these genes should prove our findings and contribute in understanding migration of carcinoma bulk complexes.
Citation Format: Helmut H. Popper, Sylvia Eidenhammer. Bulk lung cancer cell migration is more common than single cell migration and regulated by different genes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1880. doi:10.1158/1538-7445.AM2017-1880</jats:p
Karl Popper y Heráclito: antecedentes y problemas actuales de la Filosofía de la Ciencia
No full textThis essay discusses the meaning of Hereaclitus logo and
change ideas for Karl Popper's philosophy of science. The author
explains that Heraclitus has been misinterpreted and misunderstood,
especially since the critical rationalist conception, which Popper places
in the Ionian and Ephesian illustration. This has certainly involved,
according to the Austrian author, a lack of knowledge of the
contributions to scientific thinking of both philosophical, innovative
and original ideas in the pre-Socratic era. According to Popper,
Heraclito meant for the future of science and philosophy, a true link
with the innovative ideas that came over the centuries, issues that
influenced later developments of science. This work is a brief study of
the two works with which Popper studies Ephesio: Conjectures and
Refutations (1991) and The Open Society and Its Enemies (1984);
however, some connections are made with the rest of his work,
concluding that Popper bases his critical scientific rationalism on the
critical rationalism of the first Greek illustration.Se analiza el significado que tienen para la filosofía de la ciencia de Karl
Popper las ideas de logos y cambio de Heráclito de Éfeso. Este autor expone que
Heráclito ha sido mal interpretado e incomprendido, especialmente desde la
concepción racionalista crítica, que Popper sitúa en la ilustración
jónica y efesina. Ello ha implicado, según afirma, un desconocimiento
de los aportes para el pensamiento científico de ambas ideas
filosóficas, innovadoras y originales en la época presocrática. Según
Popper, Heráclito significó desde entonces, un verdadero enlace con
las ideas innovadoras que sobrevendrían al paso de los siglos,
influyendo en desarrollos posteriores de la ciencia. Este trabajo es un
breve estudio de las dos obras con las cuales Popper estudia al Efesino:
Conjeturas y refutaciones (1991) y La sociedad abierta y sus enemigos
(1984); sin embargo, se hacen algunas conexiones con el resto de su
obra, para concluir que Popper basa su racionalismo científico crítico
en el racionalismo crítico de la primera ilustración griega
The VEGF-system in primary pulmonary angiosarcomas and haemangioendotheliomas: New potential therapeutic targets?
No full textTheory testing (hypothesis testing) in agricultural economics
No full textAccording to Karl Popper, economics and agricultural economics should be deemed scientific if the theories (hypotheses) are subject to strict tests. The testing of agro-economic theories goes back 50 years in the USA, Canada, Europe, and Japan, and these methods are becoming increasingly part of educational research methodology. In fact, the author of this paper teaches this very subject at Debrecen University, and for this reason has endeavoured to provide an overview on current trends in this field. The present overview first discusses the role of testing in the research process (cognition), and then analyses the various classification methods (types) of testing. It deals in detail with the application of the (microeconomic) production-theory in agriculture and discusses the potential and limits for measuring scientific progress in this field. Finally it draws conclusions regarding future trends.theory testing, hypotheses testing, economics, agricultural economics, production-theory, Research Methods/ Statistical Methods,
Solvent Engineering for High-Performance Two-Dimensional Ruddlesden-Popper CsPbI<sub>3</sub>Solar Cells
No full textTwo-dimensional (2D) Ruddlesden-Popper (RP) CsPbI3 exhibits enhanced phase stability compared with 3D CsPbI3. However, the issue of the uncontrollable crystallization process limits its photovoltaic performance. Here, the influence of a binary mixed solvent on the film quality and photovoltaic properties of (PEA)2Cs4Pb5I16 (n = 5) is studied in detail. It is demonstrated that the crystallization rate and crystal growth can be controlled by adjusting the amount of dimethyl sulfoxide (DMSO). Optimizing the solvent composition with adding 10% DMSO in pure dimethyl formamide (DMF) leads to perfect coverage, larger flaky 2D grains, reduced grain boundaries, and a better vertical orientation to the substrate due to the formation of a more stable intermediate phase. This can form good interface contact, which is beneficial to charge transport/extraction between TiO2 (electron transport layer, ETL) and perovskite, finally resulting in improved device performance. The enhancement of the power conversion efficiency of the optimized device based on DMF/DMSO (9:1) is 3.57% compared with the reference device based on pure DMF. This work illustrates the role of crystallization kinetics in the RP CsPbI3 film and offers a simple and effective method for high-performance 2D CsPbI3 solar cells.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Photovoltaic Materials and Device
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
International capital flows : do short-term investment and direct investment differ?
No full textThe authors examine the behavior of four major components of international capital flows in 15 developing and industrial countries. Striking differences in the behavior of the component flows arise in general specifications that allow the flows to interact. For example, the behavior of international short-term investment appears to be sensitive to changes in all the other types of international capital flows, including direct investment, but direct investment appears to be insensitive to such changes. In finding that short-term investment appears to respond more dramatically to disturbances in other capital flows and in other countries than does direct investment, the authors provide empirical support for the conventional notion that short-term investment is"hot money"and direct investment is not.International Terrorism&Counterterrorism,Economic Theory&Research,Payment Systems&Infrastructure,Fiscal&Monetary Policy,Capital Markets and Capital Flows,Financial Intermediation,International Terrorism&Counterterrorism,Economic Theory&Research,Banks&Banking Reform,Capital Flows
Manipulation of the immune system by non-small cell lung cancer and possible therapeutic interference
No full textPulmonary carcinomas have developed mechanisms by which they escape the attack of immune cells. Immune checkpoint molecules programmed death 1 - programmed death ligand 1 (PD1-PDL1) and the cytotoxic T-lymphocyte antigen 4 system have gained attention. The expression of PDL1 by tumor cells causes immune tolerance, and further influences the microenvironment via orchestration by cytokines. Therapy with PDL1 antibodies could restore the cytotoxicity of T-lymphocytes towards tumor cells. Many patients will respond to this treatment. However, resistance mechanisms will counteract this therapy. New investigations have identified additional immune checkpoint inhibitors such as lymphocyte activation gene 3 and T cell immunoglobulin and mucin-domain containing-3. Tumor cells also induce tolerance by manipulating cells of the innate immune system. Macrophages are polarized to tumor-friendly M2, neutrophils into N2 types, and dendritic cells and myeloid suppressor cells are switched to assist tumor cells. Regulatory T cells enter the tumor microenvironment and signal tolerance to cytotoxic cells, inhibiting the influx of NK cells. Soluble mediators either released by tumor cells or cells of the tumor stroma induce immune tolerance, examples including tryptophan and indolamine dioxygenases, arginine and adenosine. Treatment options to counteract these molecules are currently being tested. The tumor stroma has been classified as immune-inflamed, immune-excluded, and immune-desert types. The latter might be switched to an inflamed type by induction of tertiary lymph follicles. Dendritic cells and macrophages normally phagocytose tumor antigens, but inhibitors of phagocytosis can block this. Interference with these molecules is another option for re-establishing the cytotoxic action of the immune system against tumor cells. In this review we will discuss these aspects with a special emphasis on non-small cell lung cancer
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