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Sample records for macroscopic tumor formation

  1. Macroscopic domain formation in the platelet plasma membrane

    DEFF Research Database (Denmark)

    Bali, Rachna; Savino, Laura; Ramirez, Diego A.;

    2009-01-01

    There has been ample debate on whether cell membranes can present macroscopic lipid domains as predicted by three-component phase diagrams obtained by fluorescence microscopy. Several groups have argued that membrane proteins and interactions with the cytoskeleton inhibit the formation of large d...

  2. On the macroscopic formation length for GeV photons

    CERN Document Server

    Thomsen, H D; Kirsebom, K; Knudsen, H; Uggerhøj, E; Uggerhøj1, U I; Sona, P; Mangiarotti, A; Ketel, T J; Dizdar, A; Dalton, M M; Ballestrero, S; Connell, S H

    2009-01-01

    Experimental results for the radiative energy loss of 206 and 234 GeV electrons in 5–10 μm thin Ta targets are presented. An increase in radiation emission probability at low photon energies compared to a 100 μm thick target is observed. This increase is due to the formation length of the GeV photons exceeding the thickness of the thin foils, the so-called Ternovskii–Shul'ga–Fomin (TSF) effect. The formation length of GeV photons from a multi-hundred GeV projectile is through the TSF effect shown directly to be a factor 1010 longer than their wavelength.

  3. On the macroscopic formation length for GeV photons

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, H.D.; Esberg, J.; Kirsebom, K.; Knudsen, H.; Uggerhoj, E. [Department of Physics and Astronomy, University of Aarhus (Denmark); Uggerhoj, U.I. [Department of Physics and Astronomy, University of Aarhus (Denmark)], E-mail: ulrik@phys.au.dk; Sona, P. [University of Florence, Florence (Italy); Mangiarotti, A. [LIP, Universidade de Coimbra (Portugal); Ketel, T.J. [Free University, Amsterdam (Netherlands); Dizdar, A. [University of Istanbul, Istanbul (Turkey); Dalton, M.M.; Ballestrero, S.; Connell, S.H. [University of Johannesburg, Johannesburg (South Africa)

    2009-03-02

    Experimental results for the radiative energy loss of 206 and 234 GeV electrons in 5-10 {mu}m thin Ta targets are presented. An increase in radiation emission probability at low photon energies compared to a 100 {mu}m thick target is observed. This increase is due to the formation length of the GeV photons exceeding the thickness of the thin foils, the so-called Ternovskii-Shul'ga-Fomin (TSF) effect. The formation length of GeV photons from a multi-hundred GeV projectile is through the TSF effect shown directly to be a factor 10{sup 10} longer than their wavelength.

  4. Imaging of whole tumor cut sections using a novel scanning beam confocal fluorescence MACROscope

    Science.gov (United States)

    Constantinou, Paul; Vukovic, Vojislav; Haugland, Hans K.; Nicklee, Trudey; Hedley, David W.; Wilson, Brian C.

    2001-07-01

    Hypoxia caused by inadequate structure and function of the tumor vasculature has been found to negatively determine the prognosis of cancer patients. Hence, understanding the biological basis of tumor hypoxia is of significant clinical interest. To study solid tumor microenvironments in sufficient detail, large areas (several mm in diameter) need to be imaged at micrometers resolutions. We have used a novel confocal scanning laser MACROscopeTM (CSLM) capable of acquiring images over fields of view up to 2 cm X 2 cm. To demonstrate its performance, frozen sections from a cervical carcinoma xenograft were triple labeled for tissue hypoxia, blood vessels and hypoxia-inducible transcription factor 1 alpha (HIF-1(alpha) ), imaged using the CSLM and compared to images obtained using a standard epifluorescence microscope imaging system. The results indicate that the CSLM is a useful instrument for imaging tissue-based fluorescence at resolutions comparable to standard low-power microscope objectives.

  5. Microscopic origin and macroscopic implications of lane formation in mixtures of oppositely driven particles

    Science.gov (United States)

    Klymko, Katherine; Geissler, Phillip L.; Whitelam, Stephen

    2016-08-01

    Colloidal particles of two types, driven in opposite directions, can segregate into lanes [Vissers et al., Soft Matter 7, 2352 (2011), 10.1039/c0sm01343a]. This phenomenon can be reproduced by two-dimensional Brownian dynamics simulations of model particles [Dzubiella et al., Phys. Rev. E 65, 021402 (2002), 10.1103/PhysRevE.65.021402]. Here we use computer simulation to assess the generality of lane formation with respect to variation of particle type and dynamical protocol. We find that laning results from rectification of diffusion on the scale of a particle diameter: oppositely driven particles must, in the time taken to encounter each other in the direction of the drive, diffuse in the perpendicular direction by about one particle diameter. This geometric constraint implies that the diffusion constant of a particle, in the presence of those of the opposite type, grows approximately linearly with the Péclet number, a prediction confirmed by our numerics over a range of model parameters. Such environment-dependent diffusion is statistically similar to an effective interparticle attraction; consistent with this observation, we find that oppositely driven nonattractive colloids display features characteristic of the simplest model system possessing both interparticle attractions and persistent motion, the driven Ising lattice gas [Katz, Leibowitz, and Spohn, J. Stat. Phys. 34, 497 (1984), 10.1007/BF01018556]. These features include long-ranged correlations in the disordered regime, a critical regime characterized by a change in slope of the particle current with the Péclet number, and fluctuations that grow with system size. By analogy, we suggest that lane formation in the driven colloid system is a phase transition in the macroscopic limit, but that macroscopic phase separation would not occur in finite time upon starting from disordered initial conditions.

  6. In vivo macroscopic HPD fluorescence reflectance imaging on small animals bearing surface ARO/NPA tumor

    Science.gov (United States)

    Autiero, Maddalena; Celentano, Luigi; Laccetti, Paolo; Marotta, Marcello; Mettivier, Giovanni; Montesi, Maria C.; Riccio, Patrizia; Russo, Paolo; Roberti, Giuseppe

    2005-08-01

    Recently multimodal imaging systems have been devised because the combination of different imaging modalities results in the complementarity and integration of the techniques and in a consequent improvement of the diagnostic capabilities of the multimodal system with respect to each separate imaging modality. We developed a simple and reliable HematoPorphyrin (HP) mediated Fluorescence Reflectance Imaging (FRI) system that allows for in vivo real time imaging of surface tumors with a large field of view. The tumor cells are anaplastic human thyroid carcinoma-derived ARO cells, or human papillary thyroid carcinoma-derived NPA cells. Our measurements show that the optical contrast of the tumor region image is increased by a simple digital subtraction of the background fluorescence and that HP fluorescence emissivity of ARO tumors is about 2 times greater than that of NPA tumors, and about 4 times greater than that of healthy tissues. This is also confirmed by spectroscopic measurements on histological sections of tumor and healthy tissues. It was shown also the capability of this system to distinguish the tumor type on the basis of the different intensity of the fluorescence emission, probably related to the malignancy degree. The features of this system are complementary with those ones of a pixel radionuclide detection system, which allows for relatively time expensive, narrow field of view measurements, and applicability to tumors also deeply imbedded in tissues. The fluorescence detection could be used as a large scale and quick analysis tool and could be followed by narrow field, higher resolution radionuclide measurements on previously determined highly fluorescent regions.

  7. Tundish Open Eye Formation in Inert Gas-Shrouded Tundishes: A Macroscopic Model from First Principles

    Science.gov (United States)

    Chatterjee, Saikat; Chattopadhyay, Kinnor

    2016-10-01

    Open eye formation in tundishes can result in reoxidation of liquid steel leading to the formation of harmful inclusions. Moreover, it is also a site for heat loss, gas absorption, and slag emulsification. All these factors make it necessary to understand the fundamentals of open eye formation, which in turn will allow us to prevent or control its harmful effects. In the present study, the bubble plume regions in a ladle and tundish were compared, and it was observed that there are significant differences between the two. Moreover, a simplistic model for predicting the open eye area in tundishes for `thin slag' practices was derived using the principles of conservation of mass and momentum. The proposed model was able to predict open eye areas in tundish reasonably well and was compared with other models, and experimental results.

  8. MACROSCOPIC RIVERS

    NARCIS (Netherlands)

    VANDENBERG, IP

    1991-01-01

    We present a mathematical model for the ''river-phenomenon'': striking concentrations of trajectories of ordinary differential equations. This model of ''macroscopic rivers'' is formulated within nonstandard analysis, and stated in terms of macroscopes and singular perturbations. For a subclass, the

  9. A Macroscopic Approach to the Lane Formation Phenomenon in Pedestrian Counterflow

    Institute of Scientific and Technical Information of China (English)

    XIONG Tao; ZHANG Peng; WONG S. C.; SHU Chi-Wang; ZHANG Meng-Ping

    2011-01-01

    We simulate pedestrian counterflow by adopting an optimal path-choice strategy and a recently observed speed-density relationship. Although the whole system is symmetric, the simulation demonstrates the segregation and formation of many walking lanes for two groups of pedestrians. The symmetry breaking is most likely triggered by a small numerical viscosity or "noise", and the segregation is associated with the minimization of travel time. The underlying physics can be compared with the "optimal self-organization" mechanism in Helbing's social force model, by which driven entities in an open system tend to minimize their interaction to enable them to reach some ordering state.%We simulate pedestrian counterflow by adopting an optimal path-choice strategy and a recently observed speeddensity relationship.Although the whole system is symmetric,the simulation demonstrates the segregation and formation of many walking lanes for two groups of pedestrians.The symmetry breaking is most likely triggered by a small numerical viscosity or “noise”,and the segregation is associated with the minimization of travel time.The underlying physics can be compared with the “optimal self-organization” mechanism in Helbing's social force model,by which driven entities in an open system tend to minimize their interaction to enable them to reach some ordering state.The phenomenon of lane formation in pedestrian flows has been frequently observed through direct observation or controlled experiments.Helbing et al.[4]presented photographs to show that pedestrians could form uniform walking lanes at sufficiently high densities.Theoretically,the phenomenon was explained through an optimal self-organization mechanism,[3,6]namely,a pedestrian crowd constitutes an open system of driven entities that tends to minimize interaction and dissipation,and thus an optimal state is reached.This differs from a closed system,which is governed by the second law of thermodynamics and thus the entropy

  10. Cell Competition Drives the Formation of Metastatic Tumors in a Drosophila Model of Epithelial Tumor Formation

    DEFF Research Database (Denmark)

    Eichenlaub, Teresa; Cohen, Stephen M; Herranz, Héctor

    2016-01-01

    Cell competition is a homeostatic process in which proliferating cells compete for survival. Elimination of otherwise normal healthy cells through competition is important during development and has recently been shown to contribute to maintaining tissue health during organismal aging. The mechan......Cell competition is a homeostatic process in which proliferating cells compete for survival. Elimination of otherwise normal healthy cells through competition is important during development and has recently been shown to contribute to maintaining tissue health during organismal aging....... The mechanisms that allow for ongoing cell competition during adult life could, in principle, contribute to tumorigenesis. However, direct evidence supporting this hypothesis has been lacking. Here, we provide evidence that cell competition drives tumor formation in a Drosophila model of epithelial cancer. Cells...... of the Septin family protein Peanut. Cytokinesis failure due to downregulation of Peanut is required for tumorigenesis. This study provides evidence that the cellular mechanisms that drive cell competition during normal tissue growth can be co-opted to drive tumor formation and metastasis. Analogous mechanisms...

  11. Patient-Derived Tumor Xenografts Are Susceptible to Formation of Human Lymphocytic Tumors

    Directory of Open Access Journals (Sweden)

    Gennadiy Bondarenko

    2015-09-01

    Full Text Available Patient-derived xenograft (PDX tumor models have emerged as a new approach to evaluate the effects of cancer drugs on patients’ personalized tumor grafts enabling to select the best treatment for the cancer patient and providing a new tool for oncology drug developers. Here, we report that human tumors engrafted in immunodeficient mice are susceptible to formation of B-and T-cell PDX tumors. We xenografted human primary and metastatic tumor samples into immunodeficient mice and found that a fraction of PDX tumors generated from patients’ samples of breast, colon, pancreatic, bladder and renal cancer were histologically similar to lymphocytic neoplasms. Moreover, we found that the first passage of breast and pancreatic cancer PDX tumors after initial transplantation of the tumor pieces from the same human tumor graft could grow as a lymphocytic tumor in one mouse and as an adenocarcinoma in another mouse. Whereas subcutaneous PDX tumors resembling human adenocarcinoma histology were slow growing and non-metastatic, we found that subcutaneous PDX lymphocytic tumors were fast growing and formed large metastatic lesions in mouse lymph nodes, liver, lungs, and spleen. PDX lymphocytic tumors were comprised of B-cells which were Epstein-Barr virus positive and expressed CD45 and CD20. Because B-cells are typically present in malignant solid tumors, formation of B-cell tumor may evolve in a wide range of PDX tumor models. Although PDX tumor models show great promise in the development of personalized therapy for cancer patients, our results suggest that confidence in any given PDX tumor model requires careful screening of lymphocytic markers.

  12. Acidosis Promotes Metastasis Formation by Enhancing Tumor Cell Motility.

    Science.gov (United States)

    Riemann, A; Schneider, B; Gündel, D; Stock, C; Gekle, M; Thews, O

    2016-01-01

    The tumor microenvironment is characterized by hypoxia, acidosis as well as other metabolic and biochemical alterations. Its role in cancer progression is increasingly appreciated especially on invasive capacity and the formation of metastasis. The effect of acidosis on metastasis formation of two rat carcinoma cell lines was studied in the animal model. In order to analyze the pH dependency of different steps of metastasis formation, invasiveness, cell adhesion and migration of AT-1 prostate cancer cells as well as possible underlying cell signaling pathways were studied in vitro. Acidosis significantly increased the formation of lung metastases of both tumor cell lines in vivo. In vitro, extracellular acidosis neither enhanced invasiveness nor affected cell adhesion to a plastic or to an endothelial layer. However, cellular motility was markedly elevated at pH 6.6 and this effect was sustained even when extracellular pH was switched back to pH 7.4. When analyzing the underlying mechanism, a prominent role of ROS in the induction of migration was observed. Signaling through the MAP kinases ERK1/2 and p38 as well as Src family kinases was not involved. Thus, cancer cells in an acidic microenvironment can acquire enhanced motility, which is sustained even if the tumor cells leave their acidic microenvironment e.g. by entering the blood stream. This increase depended on elevated ROS production and may contribute to the augmented formation of metastases of acidosis-primed tumor cells in vivo.

  13. Enhanced Tumor Formation in Mice Heterozygous for Blm Mutation

    Science.gov (United States)

    Heppner Goss, Kathleen; Risinger, Mary A.; Kordich, Jennifer J.; Sanz, Maureen M.; Straughen, Joel E.; Slovek, Lisa E.; Capobianco, Anthony J.; German, James; Boivin, Gregory P.; Groden, Joanna

    2002-09-01

    Persons with the autosomal recessive disorder Bloom syndrome are predisposed to cancers of many types due to loss-of-function mutations in the BLM gene, which encodes a recQ-like helicase. Here we show that mice heterozygous for a targeted null mutation of Blm, the murine homolog of BLM, develop lymphoma earlier than wild-type littermates in response to challenge with murine leukemia virus and develop twice the number of intestinal tumors when crossed with mice carrying a mutation in the Apctumor suppressor. These observations indicate that Blm is a modifier of tumor formation in the mouse and that Blm haploinsufficiency is associated with tumor predisposition, a finding with important implications for cancer risk in humans.

  14. Drosophila neural stem cells in brain development and tumor formation.

    Science.gov (United States)

    Jiang, Yanrui; Reichert, Heinrich

    2014-01-01

    Neuroblasts, the neural stem cells in Drosophila, generate the complex neural structure of the central nervous system. Significant progress has been made in understanding the mechanisms regulating the self-renewal, proliferation, and differentiation in Drosophila neuroblast lineages. Deregulation of these mechanisms can lead to severe developmental defects and the formation of malignant brain tumors. Here, the authors review the molecular genetics of Drosophila neuroblasts and discuss some recent advances in stem cell and cancer biology using this model system.

  15. Tumor blood vessels formation in osteosarcoma:vasculogenesis mimicry

    Institute of Scientific and Technical Information of China (English)

    蔡宣松; 贾永伟; 梅炯; 汤如勇

    2004-01-01

    Background Osteosarcoma is characterized by high neovascularization and a high propensity for metastasis through bloodstream. This study was to examine whether there is evidence for vasculogenic mimicry in osteosarcoma and to illustrate mechanism of tumor blood vessels formation in osteosarcoma.Methods Osteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type Ⅰ collagen. The structures of the tubular networks were observed with phase contrast microscope and transmission electron microscope (TEM). Morphometric studies using hematoxylin and eosin (HE) stain and CD31 immunohistochemical stain to show tumor-lined channels in human osteosarcoma were also performed.Results Observation with light microscope and TEM showed that highly aggressive osteosarcoma cell lines (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type Ⅰ collagen, in the absence of endothelial cells or fibroblasts. Morphometric observation using HE stain and CD31 immunohistochemical stain showed that tumor cell-lined channels were also detected in vivo in osteosarcoma; by comparison, all vascular areas in the pedicel of osteochondroma or outside osteochondroma were endothelial-lined.Conclusion These observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry.

  16. The Inhibitory Effects of Arresten Protein on Tumor Formation

    Institute of Scientific and Technical Information of China (English)

    Yi Lv; Jin-ping Zheng

    2012-01-01

    To examine the inhibitory effects of recombinant purified arresten on tumor formation.Methods Purified arresten protein was incubated with human umbilical vein endothelial cells (HUVECs) and HeLa cells in vitro.The effect on proliferation of HUVECs and HeLa cells was examined using 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide assay,and apoptosis of these cells monitored by flow cytometry.The effect on migration of HUVECs and HeLa cells was examined by Boyden chamber.Twenty colon carcinoma-bearing C67BL/6 mice were used to investigate the antitumor effects of arresten protein.The mice were randomly divided into arresten treatment group (n=10) and control group (n=10).The microvessel densities of the tumors were measured by immunohistochemical staining with anti-CD31 monoclonal antibody.Results Arresten inhibited the proliferation and migration of HUVECs in a dose-dependent manner while promoting apoptosis.However,arresten had no significant effects on the proliferation and apoptosis of HeLa cells.The migration of HeLa cells was modestly inhibited by arresten.The arresten treatment group of mice showed no weight loss or unusual behavior during the course of treatment,and the tumor growth was significantly decreased; in contrast,the control group of mice exhibited rapidly growing tumors and cachexia.A dramatically decreased microvessel density in tumor tissues was found in arresten-treated mice compared with that in the control mice.Conclusion Arresten can inhibit tumor growth through inhibition of tumor angiogenesis.

  17. Origin of Molar-Tooth Structure Based on Sequence-Stratigraphic Position and Macroscopic Features:Example from Mesoproterozoic Gaoyuzhuang Formation at Jixian Section, Tianjin, North China

    Institute of Scientific and Technical Information of China (English)

    Mei Mingxiang

    2006-01-01

    Both the macroscopic feature and the sequence-stratigraphic position of the molar-tooth structure developed in the third member of the Gaoyuzhuang (高于庄) Formation at the Jixian (蓟县)Section in Tianjin (天津) can provide some useful information about its origin and can reveal some problems to be further researched in the future. The Mesoproterozoic Gaoyuzhuang Formation is a set of ~ 1 600 m thick carbonate strata. This formation can be divided into four members. The first member is mainly made up of stromatolitic dolomites; the second is marked by a set of manganese dolomites; the third is mainly composed of lamina limestones with the development of molar-tooth strcutures; the fourth is a set of stromatolitic-lithoherm dolomites. According to lithofacies and its succession, several types of meter-scale cycles can be discerned in the Gaoyuzhuang Formation: the L-M type, the subtidal type and the peritidal type. There is a regularly vertical stacking pattern for meter-scale cycles in the third-order sequence. Therefore, the Mesoproterozoic Gaoyuzhuang Formation can be divided into 13 third-order sequences (SQ1 to SQ13 ) and can further be grouped into 4 second-order sequences. The third member is marked by lamina limestones and can be grouped into three third-order sequences (SQ9 to SQ11 ). The molar-tooth structure is developed in the middle part of the third sequence, I.e. SQ11, in the third member. Several features of this kind of molar-tooth structure reflect some features of carbonate sedimentation in the Precambrian, such as the particular configuration, abundant organic matter, and easy silication. Stromatolites are chiefly formed in a shallow tidal-flat environment; lamina are mainly formed in the shallow ramp and molar-tooth structures are mainly generated in a relatively more deep-water environment from the middle to the deep ramp. Therefore, similar to stromatolite and lamina, the molartooth structure might also be a kind of bio

  18. Formation of macroscopic surface layers on Fe(0) electrocoagulation electrodes during an extended field trial of arsenic treatment.

    Science.gov (United States)

    van Genuchten, Case M; Bandaru, Siva R S; Surorova, Elena; Amrose, Susan E; Gadgil, Ashok J; Peña, Jasquelin

    2016-06-01

    Extended field trials to remove arsenic (As) via Fe(0) electrocoagulation (EC) have demonstrated consistent As removal from groundwater to concentrations below 10 μg L(-1). However, the coulombic performance of long-term EC field operation is lower than that of laboratory-based systems. Although EC electrodes used over prolonged periods show distinct passivation layers, which have been linked to decreased treatment efficiency, the spatial distribution and mineralogy of such surface layers have not been investigated. In this work, we combine wet chemical measurements with sub-micron-scale chemical maps and selected area electron diffraction (SAED) to determine the chemical composition and mineral phase of surface layers formed during long-term Fe(0) EC treatment. We analyzed Fe(0) EC electrodes used for 3.5 months of daily treatment of As-contaminated groundwater in rural West Bengal, India. We found that the several mm thick layer that formed on cathodes and anodes consisted of primarily magnetite, with minor fractions of goethite. Spatially-resolved SAED patterns also revealed small quantities of CaCO3, Mn oxides, and SiO2, the source of which was the groundwater electrolyte. We propose that the formation of the surface layer contributes to decreased treatment performance by preventing the migration of EC-generated Fe(II) to the bulk electrolyte, where As removal occurs. The trapped Fe(II) subsequently increases the surface layer size at the expense of treatment efficiency. Based on these findings, we discuss several simple and affordable methods to prevent the efficiency loss due to the surface layer, including alternating polarity cycles and cleaning the Fe(0) surface mechanically or via electrolyte scouring.

  19. Salivary gland anlage tumor. A case with widespread necrosis and large cyst formation.

    Science.gov (United States)

    Michal, M; Sokol, L; Mukensnabl, P

    1996-05-01

    We describe a case of the salivary gland anlage tumor (congenital pleomorphic adenoma). The tumor arose in the nasopharynx as a pedunculated mass. Microscopically most of the tumor contained large necrotic areas which revealed squamous cell metaplasia resulting in the formation of large cysts. This feature has never been described previously in this tumor and might lead to an erroneous diagnosis.

  20. Is IGSF1 involved in human pituitary tumor formation?

    Science.gov (United States)

    Faucz, Fabio R; Horvath, Anelia D; Azevedo, Monalisa F; Levy, Isaac; Bak, Beata; Wang, Ying; Xekouki, Paraskevi; Szarek, Eva; Gourgari, Evgenia; Manning, Allison D; de Alexandre, Rodrigo Bertollo; Saloustros, Emmanouil; Trivellin, Giampaolo; Lodish, Maya; Hofman, Paul; Anderson, Yvonne C; Holdaway, Ian; Oldfield, Edward; Chittiboina, Prashant; Nesterova, Maria; Biermasz, Nienke R; Wit, Jan M; Bernard, Daniel J; Stratakis, Constantine A

    2015-02-01

    IGSF1 is a membrane glycoprotein highly expressed in the anterior pituitary. Pathogenic mutations in the IGSF1 gene (on Xq26.2) are associated with X-linked central hypothyroidism and testicular enlargement in males. In this study, we tested the hypothesis that IGSF1 is involved in the development of pituitary tumors, especially those that produce growth hormone (GH). IGSF1 was sequenced in 21 patients with gigantism or acromegaly and 92 healthy individuals. Expression studies with a candidate pathogenic IGSF1 variant were carried out in transfected cells and immunohistochemistry for IGSF1 was performed in the sections of GH-producing adenomas, familial somatomammotroph hyperplasia, and in normal pituitary. We identified the sequence variant p.N604T, which in silico analysis suggested could affect IGSF1 function, in two male patients and one female with somatomammotroph hyperplasia from the same family. Of 60 female controls, two carried the same variant and seven were heterozygous for other variants. Immunohistochemistry showed increased IGSF1 staining in the GH-producing tumor from the patient with the IGSF1 p.N604T variant compared with a GH-producing adenoma from a patient negative for any IGSF1 variants and with normal control pituitary tissue. The IGSF1 gene appears polymorphic in the general population. A potentially pathogenic variant identified in the germline of three patients with gigantism from the same family (segregating with the disease) was also detected in two healthy female controls. Variations in IGSF1 expression in pituitary tissue in patients with or without IGSF1 germline mutations point to the need for further studies of IGSF1 action in pituitary adenoma formation.

  1. Is IGSF1 involved in human pituitary tumor formation?

    Science.gov (United States)

    Faucz, Fabio R.; Horvath, Anelia D.; Azevedo, Monalisa F.; Levy, Isaac; Bak, Beata; Wang, Ying; Xekouki, Paraskevi; Szarek, Eva; Gourgari, Evgenia; Manning, Allison D.; de Alexandre, Rodrigo Bertollo; Saloustros, Emmanouil; Trivellin, Giampaolo; Lodish, Maya; Hofman, Paul; Anderson, Yvonne C; Holdaway, Ian; Oldfield, Edward; Chittiboina, Prashant; Nesterova, Maria; Biermasz, Nienke R.; Wit, Jan M.; Bernard, Daniel J.; Stratakis, Constantine A.

    2014-01-01

    IGSF1 is a membrane glycoprotein highly expressed in the anterior pituitary. Pathogenic mutations in the IGSF1 gene (on Xq26.2) are associated with X-linked central hypothyroidism and testicular enlargement in males. In this study we tested the hypothesis that IGSF1 is involved in the development of pituitary tumors, especially those that produce growth hormone (GH). IGSF1 was sequenced in 21 patients with gigantism or acromegaly and 92 healthy individuals. Expression studies with a candidate pathogenic IGSF1 variant were carried out in transfected cells and immunohistochemistry for IGSF1 was performed in sections from GH-producing adenomas, familial somatomammotroph hyperplasia and in normal pituitary. In two male patients, and in one female, with somatomammotroph hyperplasia from the same family, we identified the sequence variant p.N604T, which in silico analysis suggested could affect IGSF1 function. Of 60 female controls, two carried the same variant, and seven were heterozygous for other variants. Immunohistochemistry showed increase IGSF1 staining in the GH-producing tumor from the patient with the IGSF1 p.N604T variant compared to a GH-producing adenoma from a patient negative for any IGSF1 variants and to normal control pituitary tissue. The IGSF1 gene appears polymorphic in the general population. A potentially pathogenic variant identified in the germline of three patients with gigantism from the same family (segregating with the disease) was also detected in two healthy female controls. Variations in IGSF1 expression in pituitary tissue in patients with or without IGSF1 germline mutations point to the need for further studies of IGSF1 action in pituitary adenoma formation. PMID:25527509

  2. Interference of macroscopic superpositions

    CERN Document Server

    Vecchi, I

    2000-01-01

    We propose a simple experimental procedure based on the Elitzur-Vaidman scheme to implement a quantum nondemolition measurement testing the persistence of macroscopic superpositions. We conjecture that its implementation will reveal the persistence of superpositions of macroscopic objects in the absence of a direct act of observation.

  3. Liver tumor formation by a mutant retinoblastoma protein in the transgenic mice is caused by an upregulation of c-Myc target genes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Hikosaka, Keisuke; Sultana, Nishat; Sharkar, Mohammad Tofael Kabir [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Noritake, Hidenao [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Kimura, Wataru; Wu, Yi-Xin [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Kobayashi, Yoshimasa [Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Uezato, Tadayoshi [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan); Miura, Naoyuki, E-mail: nmiura@hama-med.ac.jp [Department of Biochemistry, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192 (Japan)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Fifty percent of the mutant Rb transgenic mice produced liver tumors. Black-Right-Pointing-Pointer In the tumor, Foxm1, Skp2, Bmi1 and AP-1 mRNAs were up-regulated. Black-Right-Pointing-Pointer No increase in expression of the Myc-target genes was observed in the non-tumorous liver. Black-Right-Pointing-Pointer Tumor formation depends on up-regulation of the Myc-target genes. -- Abstract: The retinoblastoma (Rb) tumor suppressor encodes a nuclear phosphoprotein that regulates cellular proliferation, apoptosis and differentiation. In order to adapt itself to these biological functions, Rb is subjected to modification cycle, phosphorylation and dephosphorylation. To directly determine the effect of phosphorylation-resistant Rb on liver development and function, we generated transgenic mice expressing phosphorylation-resistant human mutant Rb (mt-Rb) under the control of the rat hepatocyte nuclear factor-1 gene promoter/enhancer. Expression of mt-Rb in the liver resulted in macroscopic neoplastic nodules (adenomas) with {approx}50% incidence within 15 months old. Interestingly, quantitative reverse transcriptase-PCR analysis showed that c-Myc was up-regulated in the liver of mt-Rb transgenic mice irrespective of having tumor tissues or no tumor. In tumor tissues, several c-Myc target genes, Foxm1, c-Jun, c-Fos, Bmi1 and Skp2, were also up-regulated dramatically. We determined whether mt-Rb activated the Myc promoter in the HTP9 cells and demonstrated that mt-Rb acted as an inhibitor of wild-type Rb-induced repression on the Myc promoter. Our results suggest that continued upregulation of c-Myc target genes promotes the liver tumor formation after about 1 year of age.

  4. Amplification of Mdmx (or Mdm4) directly contributes to tumor formation by inhibiting p53 tumor suppressor activity

    DEFF Research Database (Denmark)

    Danovi, Davide; Meulmeester, Erik; Pasini, Diego

    2004-01-01

    Human tumors are believed to harbor a disabled p53 tumor suppressor pathway, either through direct mutation of the p53 gene or through aberrant expression of proteins acting in the p53 pathway, such as p14(ARF) or Mdm2. A role for Mdmx (or Mdm4) as a key negative regulator of p53 function in vivo...... has been established. However, a direct contribution of Mdmx to tumor formation remains to be demonstrated. Here we show that retrovirus-mediated Mdmx overexpression allows primary mouse embryonic fibroblast immortalization and leads to neoplastic transformation in combination with HRas(V12......). Furthermore, the human Mdmx ortholog, Hdmx, was found to be overexpressed in a significant percentage of various human tumors and amplified in 5% of primary breast tumors, all of which retained wild-type p53. Hdmx was also amplified and highly expressed in MCF-7, a breast cancer cell line harboring wild...

  5. Effect of single-walled carbon nanotubes on tumor cells viability and formation of multicellular tumor spheroids

    Science.gov (United States)

    Yakymchuk, Olena M.; Perepelytsina, Olena M.; Dobrydnev, Alexey V.; Sydorenko, Mychailo V.

    2015-03-01

    This paper describes the impact of different concentrations of single-walled carbon nanotubes (SWCNTs) on cell viability of breast adenocarcinoma, MCF-7 line, and formation of multicellular tumor spheroids (MTS). Chemical composition and purity of nanotubes is controlled by Fourier transform infrared spectroscopy. The strength and direction of the influence of SWCNTs on the tumor cell population was assessed by cell counting and measurement of the volume of multicellular tumor spheroids. Effect of SWCNTs on the formation of multicellular spheroids was compared with the results obtained by culturing tumor cells with ultra dispersed diamonds (UDDs). Our results demonstrated that SWCNTs at concentrations ranging from 12.5 to 50 μg/ml did not have cytotoxic influence on tumor cells; instead, they had weak cytostatic effect. The increasing of SWCNTs concentration to 100 to 200 μg/ml stimulated proliferation of tumor cells, especially in suspension fractions. The result of this influence was in formation of more MTS in cell culture with SWCNTs compared with UDDs and control samples. In result, the median volume of MTS after cultivation with SWCNTs at 100 to 200 μg/ml concentrations is 3 to 5 times greater than that in samples which were incubated with the UDDs and is 2.5 times greater than that in control cultures. So, if SWCNTs reduced cell adhesion to substrate and stimulated formation of tumor cell aggregates volume near 7 · 10-3 mm3, at the same time, UDDs reduced adhesion and cohesive ability of cells and stimulated generation of cell spheroids volume no more than 4 · 10-3 mm3. Our results could be useful for the control of cell growth in three-dimensional culture.

  6. Tumor interstitial fluid formation, characterization and clinical implications

    Directory of Open Access Journals (Sweden)

    Marek eWagner

    2015-05-01

    Full Text Available The interstitium, situated between the blood and lymph vessels and the cells, consists of a solid or matrix phase and a fluid phase, together constituting the tissue microenvironment. In the present review we focus on the interstitial fluid phase of solid tumors (TIF, i.e. the fluid bathing the tumor and stroma cells, also including immune cells. This is a component of the internal milieu of a solid tumor that has attracted regained attention. Access to this compartment may provide important insight into how tumors develop and how they respond to therapy. TIF is formed by transcapillary filtration, and since fluid is not readily available we discuss available techniques for TIF isolation, results from subsequent characterization and implications of recent findings with respect to transcapillary fluid balance and uptake of macromolecular therapeutic agents. It has recently been shown that local gradients exist in signaling substances from neoplastic tissue to plasma that may provide new insight into the biology of tumors. The emergence of sensitive proteomic technologies has made the interstitial fluid compartment in general, but that of tumors in particular, a highly valuable source for tissue specific proteins that may serve as biomarker candidates. Potential biomarkers will appear locally at high concentrations in the tissue of interest and will eventually appear in the plasma where they are diluted. Access to fluid that reliably reflects the local microenvironment enables us to identify substances that can be used in early detection and monitoring of disease.

  7. FORMATION OF NECROTIC CORES IN THE GROWTH OF TUMORS: ANALYTIC RESULTS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this article, the author studies the mechanism of formation of necrotic cores in the growth of tumors by using rigorous analysis of a mathematical model. The model modifies a corresponding tumor growth model proposed by Byrne and Chaplain in 1996, in the case where no inhibitors exist. The modification is made such that both necrotic tumors and nonnecrotic tumors can be considered in a joint way. It is proved that if the nutrient supply is below a threshold value, then there is not dormant tumor,and all evolutionary tumors will finally vanish. If instead the nutrient supply is above this threshold value then there is a unique dormant tumor which can either be necrotic or nonnecrotic, depending on the level of the nutrient supply and the level of dead-cell dissolution rate, and all evolutionary tumors will converge to this dormant tumor. It is also proved that, in the second case, if the dormant tumor is necrotic then an evolutionary tumor will form a necrotic core at a finite time, and if the dormant tumor is nonnecrotic then an evolutionary tumor will also be nonnecrotic from a finite time.

  8. Macroscopic quantum resonators (MAQRO)

    CERN Document Server

    Kaltenbaek, Rainer; Kiesel, Nikolai; Romero-Isart, Oriol; Johann, Ulrich; Aspelmeyer, Markus

    2012-01-01

    Quantum physics challenges our understanding of the nature of physical reality and of space-time and suggests the necessity of radical revisions of their underlying concepts. Experimental tests of quantum phenomena involving massive macroscopic objects would provide novel insights into these fundamental questions. Making use of the unique environment provided by space, MAQRO aims at investigating this largely unexplored realm of macroscopic quantum physics. MAQRO has originally been proposed as a medium-sized fundamental-science space mission for the 2010 call of Cosmic Vision. MAQRO unites two experiments: DECIDE (DECoherence In Double-Slit Experiments) and CASE (Comparative Acceleration Sensing Experiment). The main scientific objective of MAQRO, which is addressed by the experiment DECIDE, is to test the predictions of quantum theory for quantum superpositions of macroscopic objects containing more than 10e8 atoms. Under these conditions, deviations due to various suggested alternative models to quantum th...

  9. Pathophysiological Basis for the Formation of the Tumor Microenvironment

    DEFF Research Database (Denmark)

    Horsman, Michael R; Vaupel, Peter

    2016-01-01

    Poor microenvironmental conditions are a characteristic feature of solid tumors. Such conditions occur because the tumor vascular supply, which develops from the normal host vasculature by the process of angiogenesis, is generally inadequate in meeting the oxygen and nutrient demands of the growing...... as a single entity, yet we now know that it is multifactorial. Furthermore, hypoxia is often associated with other microenvironmental parameters, such as elevated interstitial fluid pressure, glycolysis, low pH, and reduced bioenergetic status, and these can also influence the effects of hypoxia. Here, we...... review the various aspects of hypoxia, but also discuss the role of the other microenvironmental parameters associated with hypoxia....

  10. Identification of a population of epidermal squamous cell carcinoma cells with enhanced potential for tumor formation.

    Directory of Open Access Journals (Sweden)

    Gautam Adhikary

    Full Text Available Epidermal squamous cell carcinoma is among the most common cancers in humans. These tumors are comprised of phenotypically diverse populations of cells that display varying potential for proliferation and differentiation. An important goal is identifying cells from this population that drive tumor formation. To enrich for tumor-forming cells, cancer cells were grown as spheroids in non-attached conditions. We show that spheroid-selected cells form faster growing and larger tumors in immune-compromised mice as compared to non-selected cells. Moreover, spheroid-selected cells gave rise to tumors following injection of as few as one hundred cells, suggesting these cells have enhanced tumor-forming potential. Cells isolated from spheroid-selected tumors retain an enhanced ability to grow as spheroids when grown in non-attached culture conditions. Thus, these tumor-forming cells retain their phenotype following in vivo passage as tumors. Detailed analysis reveals that spheroid-selected cultures are highly enriched for expression of epidermal stem cell and embryonic stem cell markers, including aldehyde dehydrogenase 1, keratin 15, CD200, keratin 19, Oct4, Bmi-1, Ezh2 and trimethylated histone H3. These studies indicate that a subpopulation of cells that possess stem cell-like properties and express stem cell markers can be derived from human epidermal cancer cells and that these cells display enhanced ability to drive tumor formation.

  11. Calcium Glucarate Prevents Tumor Formation in Mouse Skin

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Objective Calcium Glucarate (Cag), Ca salt of D-glucaric acid is a naturally occurring non-toxic compound present in fruits, vegetables and seeds of some plants, and suppress tumor growth in different models. Due to lack of knowledge about its mode of action its uses are limited in cancer chemotherapy thus the objective of the study was to study the mechanism of action of Cag on mouse skin tumorigenesis. Methods We have estimated effect of Cag on DMBA induced mouse skin tumor development following complete carcinogenesis protocol. We measured, epidermal transglutaminase activity (TG), a marker of cell differentiation after DMBA and/or Cag treatment and [3H] thymidine incorporation into DNA as a marker for cell proliferation. Results Topical application of Cag suppressed the DMBA induced mouse skin tumor development. Topical application of Cag significantly modifies the critical events of proliferation and differentiation TG activity was found to be reduced after DMBA treatment. Reduction of the TG activity was dependent on the dose of DMBA and duration of DMBA exposure. Topical application of Cag significantly alleviated DMBA induced inhibition of TG. DMBA also caused stimulation of DNA synthesis in epidermis, which was inhibited by Cag. Conclusion Cag inhibits DMBA induced mouse skin tumor development. Since stimulation of DNA synthesis reflects proliferation and induction of TG represents differentiation, the antitumorigenic effect of Cag is considered to be possibly due to stimulation of differentiation and suppression of proliferation.

  12. Tumor formation in Hoffa's infrapatellar fat: Case report

    Directory of Open Access Journals (Sweden)

    Alan de Paula Mozella

    2015-02-01

    Full Text Available Although tumors or pseudotumoral lesions are rare in the infrapatellar fat, they may affect it. Osteochondroma is the commonest benign bone tumor. However, extraskeletal presentations are rare. There are three extraskeletal variants of osteochondroma: synovial chondromatosis, para-articular chondroma and soft-tissue chondroma. We present a case of a single intra-articular lesion in the area of Hoffa's fat, in a 78-year-old female patient with a complaint of progressive knee pain associated with severe arthrosis. From the clinical and radiological findings, the diagnosis was para-articular osteochondroma. However, the histopathological findings, after excision of the lesion, showed that this was synovial chondromatosis secondary to osteoarthrosis.

  13. Adiponectin deficiency enhances colorectal carcinogenesis and liver tumor formation induced by azoxymethane in mice

    Institute of Scientific and Technical Information of China (English)

    Tamao Nishihara; Shinji Tamura; Norio Hayashi; Hiroyasu Iishi; Iichiro Shimornura; Miyako Baba; Morihiro Matsuda; Masahiro Inoue; Yasuko Nishizawa; Atsunori Fukuhara; Hiroshi Arald; Shinji Kihara; Tohru Funahashi

    2008-01-01

    AIM: To investigate the causal relationship between hypoadiponectinemia and colorectal carcinogenesis in in vivo experimental model, and to determine the con-tribution of adiponectin deficiency to colorectal cancer development and proliferation. METHODS: We examined the influence of adiponectin deficiency on colorectal carcinogenesis induced by the administration of azoxymethane (AOM) (7.5 mg/kg, in-traperitoneal injection once a week for 8 wk), by using adiponectin-knockout (KO) mice. RESULTS: At 53 wk after the first AOM treatment, KOmice developed larger and histologically more progres-sive colorectal tumors with greater frequency com-pared with wild-type (WT) mice, although the tumor incidence was not different between WT and KO mice. KO mice showed increased cell proliferation of colorec-tal tumor cells, which correlated with the expression levels of cyclooxygenase-2 (COX-2) in the colorectal tumors. In addition, KO mice showed higher incidence and frequency of liver tumors after AOI treatment. Thirteen percent of WT mice developed liver tumors, and these WT mice had only a single tumor. In contrast, 50% of K.O mice developed liver tumors, and 58% of these KO mice had multiple tumors. CONCLUSION: Adiponectin deficiency enhances colorectal carcinogenesis and liver tumor formation induced by AOM in mice. This study strongly suggests that hypoadiponectinemia could be involved in the pathogenesis for colorectal cancer and liver tumor in human subjects.

  14. Tumorer

    DEFF Research Database (Denmark)

    Prause, J.U.; Heegaard, S.

    2005-01-01

    oftalmologi, øjenlågstumorer, conjunctivale tumorer, malignt melanom, retinoblastom, orbitale tumorer......oftalmologi, øjenlågstumorer, conjunctivale tumorer, malignt melanom, retinoblastom, orbitale tumorer...

  15. Id2 deletion attenuates Apc-deficient ileal tumor formation

    Directory of Open Access Journals (Sweden)

    Kyoko Biyajima

    2015-08-01

    Full Text Available The expression level of inhibitor of DNA binding 2 (Id2 is increased in colorectal carcinomas and is positively correlated with poor prognosis. However, the functional significance of Id2 in intestinal tumorigenesis has not been fully defined using genetic approaches. Here, we show that Id2 promotes ileal tumor initiation in Apc-deficient mice. Expression of Id2 was stimulated by Wnt signaling through the enhancer region of the Id2 promoter at the early stage of tumorigenesis in Apc+/Δ716 (ApcΔ716 mice. Genetic depletion of Id2 in ApcΔ716 mice caused ∼80% reduction in the number of ileal polyps, but had little effect on tumor size. Notably, the lack of Id2 increased the number of apoptotic cells in the normal crypt epithelium of the mice. Furthermore, DNA microarray analysis revealed that the expression level of Max dimerization protein 1 (Mxd1, known as a c-Myc antagonist, was specifically increased by Id2 deletion in the ileal intestinal epithelium of ApcΔ716 mice. In contrast, the protein level of c-Myc, but not the mRNA level, was decreased by loss of Id2 in these mice. These results indicate that loss of Id2 inhibits tumor initiation by up-regulation of Mxd1 and down-regulation of c-Myc in ApcΔ716 mice.

  16. Mammary gland tumor formation in transgenic mice overexpressing stromelysin-1

    Energy Technology Data Exchange (ETDEWEB)

    Sympson, Carolyn J; Bissell, Mina J; Werb, Zena

    1995-06-01

    An intact basement membrane (BM) is essential for the proper function, differentiation and morphology of many epithelial cells. The disruption or loss of this BM occurs during normal development as well as in the disease state. To examine the importance of BM during mammary gland development in vivo, we generated transgenic mice that inappropriately express autoactivating isoforms of the matrix metalloproteinase stromelysin-1. The mammary glands from these mice are both functionally and morphologically altered throughout development. We have now documented a dramatic incidence of breast tumors in several independent lines of these mice. These data suggest that overexpression of stromelysin-1 and disruption of the BM may be a key step in the multi-step process of breast cancer.

  17. Blood clot formation does not affect metastasis formation or tumor growth in a murine model of breast cancer.

    Directory of Open Access Journals (Sweden)

    Stephanie Rossnagl

    Full Text Available Cancer is associated with increased fracture risk, due either to metastasis or associated osteoporosis. After a fracture, blood clots form. Because proteins of the coagulation cascade and activated platelets promote cancer development, a fracture in patients with cancer often raises the question whether it is a pathologic fracture or whether the fracture itself might promote the formation of metastatic lesions. We therefore examined whether blood clot formation results in increased metastasis in a murine model of experimental breast cancer metastasis. For this purpose, a clot was surgically induced in the bone marrow of the left tibia of immundeficient mice. Either one minute prior to or five minutes after clot induction, human cancer cells were introduced in the circulation by intracardiac injection. The number of cancer cells that homed to the intervention site was determined by quantitative real-time PCR and flow cytometry. Metastasis formation and longitudinal growth were evaluated by bioluminescence imaging. The number of cancer cells that homed to the intervention site after 24 hours was similar to the number of cells in the opposite tibia that did not undergo clot induction. This effect was confirmed using two more cancer cell lines. Furthermore, no difference in the number of macroscopic lesions or their growth could be detected. In the control group 72% developed a lesion in the left tibia. In the experimental groups with clot formation 79% and 65% developed lesions in the left tibia (p = ns when comparing each experimental group with the controls. Survival was similar too. In summary, the growth factors accumulating in a clot/hematoma are neither enough to promote cancer cell homing nor support growth in an experimental model of breast cancer bone metastasis. This suggests that blood clot formation, as occurs in traumatic fractures, surgical interventions, and bruises, does not increase the risk of metastasis formation.

  18. Effects of Blood-Activating and Stasis-Resolving Drugs on Tumor Formation and Metastasis

    Institute of Scientific and Technical Information of China (English)

    QIAN Yan-fang; WANG Xiao-jing; DUAN Shu-min

    2009-01-01

    @@ In order to summarize and analyze the internal relations of tumor formation and metastasis to blood-stasis syndrome and the influential factors of blood-activating and stasis-resolving drugs (BASRD) on tumor inhibition and metastasis, and to grasp the opportunity of selecting and using BASRD, the authors have retrieved by the computer the relative literature published from 1985 to 2006 in Full-text Database of Chinese Periodicals with "BASRD" and "cancer" as retrieval words.

  19. Impaired Preneoplastic Changes and Liver Tumor Formation in Tumor Necrosis Factor Receptor Type 1 Knockout Mice

    OpenAIRE

    Knight, Belinda; Yeoh, George C.T.; Husk, Kirsten L.; Ly, Tina; Abraham, Lawrence J; Yu, Changpu; Rhim, Jonathan A.; Fausto, Nelson

    2000-01-01

    Hepatic stem cells (oval cells) proliferate within the liver after exposure to a variety of hepatic carcinogens and can generate both hepatocytes and bile duct cells. Oval cell proliferation is commonly seen in the preneoplastic stages of liver carcinogenesis, often accompanied by an inflammatory response. Tumor necrosis factor (TNF), an inflammatory cytokine, is also important in liver regeneration and hepatocellular growth. The experiments reported here explore the relationship among the TN...

  20. Food-grade titanium dioxide exposure exacerbates tumor formation in colitis associated cancer model.

    Science.gov (United States)

    Urrutia-Ortega, Ismael M; Garduño-Balderas, Luis G; Delgado-Buenrostro, Norma L; Freyre-Fonseca, Verónica; Flores-Flores, José O; González-Robles, Arturo; Pedraza-Chaverri, José; Hernández-Pando, Rogelio; Rodríguez-Sosa, Miriam; León-Cabrera, Sonia; Terrazas, Luis I; van Loveren, Henk; Chirino, Yolanda I

    2016-07-01

    Colorectal cancer is the fourth worldwide cause of death and even if some dietary habits are consider risk factors, the contribution of food additives including foodgrade titanium dioxide (TiO2), designated as E171, has been poorly investigated. We hypothesized that oral E171 intake could have impact on the enhancement of colorectal tumor formation and we aimed to investigate if E171 administration could enhance tumor formation in a colitis associated cancer (CAC) model. BALB/c male mice were grouped as follows: a) control, b) E171, c) CAC and d) CAC + E171 group (n = 6). E171 used in this study formed agglomerates of 300 nm in water. E171 intragastric administration (5 mg/kg body weight/5 days/10 weeks) was unable to induce tumor formation but dysplastic alterations were observed in the distal colon but enhanced the tumor formation in distal colon (CAC + E171 group) measured by tumor progression markers. Some E171 particles were internalized in colonic cells of the E171 and CAC + E171 groups and both groups showed a decrease in goblet cells in the distal colon. However the CAC + E171 group showed a higher decrease of these cells that act as protection barrier in colon. These results suggest that E171 could worsen pre-existent intestinal diseases.

  1. Photoacoustic monitoring of clot formation during surgery and tumor surgery

    Science.gov (United States)

    Juratli, Mazen A.; Galanzha, Ekaterina I.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Suen, James Y.; Zharov, Vladimir P.

    2013-03-01

    When a blood vessel is injured, the normal physiological response of the body is to form a clot (thrombus) to prevent blood loss. Alternatively, even without injury to the blood vessel, the pathological condition called thromboembolism may lead to the formation of circulating blood clots (CBCs), also called emboli, which can clog blood vessels throughout the body. Veins of the extremities (venous thromboembolism), lungs (pulmonary embolism ), brain (embolic stroke), heart (myocardial infarction), kidneys, and gastrointestinal tract are often affected. Emboli are also common complications of infection, inflammation, cancer, surgery, radiation and coronary artery bypass grafts. Despite the clear medical significance of CBCs, however, little progress has been made in the development of methods for real-time detection and identification of CBCs. To overcome these limitations, we developed a new modification of in vivo photoacoustic (PA) flow cytometry (PAFC) for real-time detection of white, red, and mixed clots through a transient decrease, increase or fluctuation of PA signal amplitude, respectively. In this work, using PAFC and mouse models, we present for the first time direct evidence that some medical procedures, such as conventional or cancer surgery may initiate the formation of CBCs. In conclusion, the PA diagnostic platform can be used in real-time to define risk factors for cardiovascular diseases, assist in the prognosis and potential prevention of stroke by using a well-timed therapy or as a clot count as a marker of therapy efficacy.

  2. Monoallelic loss of the imprinted gene Grb10 promotes tumor formation in irradiated Nf1+/- mice.

    Directory of Open Access Journals (Sweden)

    Rana Mroue

    2015-05-01

    Full Text Available Imprinted genes are expressed from only one parental allele and heterozygous loss involving the expressed allele is sufficient to produce complete loss of protein expression. Genetic alterations are common in tumorigenesis but the role of imprinted genes in this process is not well understood. In earlier work we mutagenized mice heterozygous for the Neurofibromatosis I tumor suppressor gene (NF1 to model radiotherapy-associated second malignant neoplasms that arise in irradiated NF1 patients. Expression analysis of tumor cell lines established from our mouse models identified Grb10 expression as widely absent. Grb10 is an imprinted gene and polymorphism analysis of cell lines and primary tumors demonstrates that the expressed allele is commonly lost in diverse Nf1 mutant tumors arising in our mouse models. We performed functional studies to test whether Grb10 restoration or loss alter fundamental features of the tumor growth. Restoring Grb10 in Nf1 mutant tumors decreases proliferation, decreases soft agar colony formation and downregulates Ras signaling. Conversely, Grb10 silencing in untransformed mouse embryo fibroblasts significantly increased cell proliferation and increased Ras-GTP levels. Expression of a constitutively activated MEK rescued tumor cells from Grb10-mediated reduction in colony formation. These studies reveal that Grb10 loss can occur during in vivo tumorigenesis, with a functional consequence in untransformed primary cells. In tumors, Grb10 loss independently promotes Ras pathway hyperactivation, which promotes hyperproliferation, an early feature of tumor development. In the context of a robust Nf1 mutant mouse model of cancer this work identifies a novel role for an imprinted gene in tumorigenesis.

  3. Tumor Cell Seeding During Surgery—Possible Contribution to Metastasis Formations

    Energy Technology Data Exchange (ETDEWEB)

    Katharina, Pachmann [Department of Experimental Hematology and Oncology, Clinic for Internal Medicine II, Friedrich Schiller University, Jena D-07747 (Germany)

    2011-06-08

    In spite of optimal local control in breast cancer, distant metastases can develop as a systemic part of this disease. Surgery is suspected to contribute to metastasis formation activating dormant tumor cells. Here we add data that seeding of cells during surgery may add to the risk of metastasis formation. The change in circulating epithelial tumor cells (CETC) was monitored in 66 breast cancer patients operated on with breast conserving surgery or mastectomy and during the further course of the disease, analyzing CETC from unseparated white blood cells stained with FITC-anti-EpCAM. An increase in cell numbers lasting until the start of chemotherapy was observed in about one third of patients. It was more preeminent in patients with low numbers of CETC before surgery and, surprisingly, in patients without involved lymph nodes. Patients with the previously reported behavior—Reincrease in cell numbers during adjuvant chemotherapy and subsequent further increase during maintenance therapy—were at increased risk of relapse. In addition to tumor cells already released during growth of the tumor, cell seeding during surgery may contribute to the early peak of relapses observed after removal of the primary tumor and chemotherapy may only marginally postpone relapse in patients with aggressively growing tumors.

  4. MUC16 provides immune protection by inhibiting synapse formation between NK and ovarian tumor cells

    Directory of Open Access Journals (Sweden)

    Migneault Martine

    2010-01-01

    Full Text Available Abstract Background Cancer cells utilize a variety of mechanisms to evade immune detection and attack. Effective immune detection largely relies on the formation of an immune synapse which requires close contact between immune cells and their targets. Here, we show that MUC16, a heavily glycosylated 3-5 million Da mucin expressed on the surface of ovarian tumor cells, inhibits the formation of immune synapses between NK cells and ovarian tumor targets. Our results indicate that MUC16-mediated inhibition of immune synapse formation is an effective mechanism employed by ovarian tumors to evade immune recognition. Results Expression of low levels of MUC16 strongly correlated with an increased number of conjugates and activating immune synapses between ovarian tumor cells and primary naïve NK cells. MUC16-knockdown ovarian tumor cells were more susceptible to lysis by primary NK cells than MUC16 expressing controls. This increased lysis was not due to differences in the expression levels of the ligands for the activating receptors DNAM-1 and NKG2D. The NK cell leukemia cell line (NKL, which does not express KIRs but are positive for DNAM-1 and NKG2D, also conjugated and lysed MUC16-knockdown cells more efficiently than MUC16 expressing controls. Tumor cells that survived the NKL challenge expressed higher levels of MUC16 indicating selective lysis of MUC16low targets. The higher csMUC16 levels on the NKL resistant tumor cells correlated with more protection from lysis as compared to target cells that were never exposed to the effectors. Conclusion MUC16, a carrier of the tumor marker CA125, has previously been shown to facilitate ovarian tumor metastasis and inhibits NK cell mediated lysis of tumor targets. Our data now demonstrates that MUC16 expressing ovarian cancer cells are protected from recognition by NK cells. The immune protection provided by MUC16 may lead to selective survival of ovarian cancer cells that are more efficient in

  5. MUC16 provides immune protection by inhibiting synapse formation between NK and ovarian tumor cells.

    Science.gov (United States)

    Gubbels, Jennifer A A; Felder, Mildred; Horibata, Sachi; Belisle, Jennifer A; Kapur, Arvinder; Holden, Helen; Petrie, Sarah; Migneault, Martine; Rancourt, Claudine; Connor, Joseph P; Patankar, Manish S

    2010-01-20

    Cancer cells utilize a variety of mechanisms to evade immune detection and attack. Effective immune detection largely relies on the formation of an immune synapse which requires close contact between immune cells and their targets. Here, we show that MUC16, a heavily glycosylated 3-5 million Da mucin expressed on the surface of ovarian tumor cells, inhibits the formation of immune synapses between NK cells and ovarian tumor targets. Our results indicate that MUC16-mediated inhibition of immune synapse formation is an effective mechanism employed by ovarian tumors to evade immune recognition. Expression of low levels of MUC16 strongly correlated with an increased number of conjugates and activating immune synapses between ovarian tumor cells and primary naïve NK cells. MUC16-knockdown ovarian tumor cells were more susceptible to lysis by primary NK cells than MUC16 expressing controls. This increased lysis was not due to differences in the expression levels of the ligands for the activating receptors DNAM-1 and NKG2D. The NK cell leukemia cell line (NKL), which does not express KIRs but are positive for DNAM-1 and NKG2D, also conjugated and lysed MUC16-knockdown cells more efficiently than MUC16 expressing controls. Tumor cells that survived the NKL challenge expressed higher levels of MUC16 indicating selective lysis of MUC16(low) targets. The higher csMUC16 levels on the NKL resistant tumor cells correlated with more protection from lysis as compared to target cells that were never exposed to the effectors. MUC16, a carrier of the tumor marker CA125, has previously been shown to facilitate ovarian tumor metastasis and inhibits NK cell mediated lysis of tumor targets. Our data now demonstrates that MUC16 expressing ovarian cancer cells are protected from recognition by NK cells. The immune protection provided by MUC16 may lead to selective survival of ovarian cancer cells that are more efficient in metastasizing within the peritoneal cavity and also at overcoming

  6. USP10 Antagonizes c-Myc Transcriptional Activation through SIRT6 Stabilization to Suppress Tumor Formation

    Directory of Open Access Journals (Sweden)

    Zhenghong Lin

    2013-12-01

    Full Text Available The reduced protein expression of SIRT6 tumor suppressor is involved in tumorigenesis. The molecular mechanisms underlying SIRT6 protein downregulation in human cancers remain unknown. Using a proteomic approach, we have identified the ubiquitin-specific peptidase USP10, another tumor suppressor, as one of the SIRT6-interacting proteins. USP10 suppresses SIRT6 ubiquitination to protect SIRT6 from proteasomal degradation. USP10 antagonizes the transcriptional activity of the c-Myc oncogene through SIRT6, as well as p53, to inhibit cell-cycle progression, cancer cell growth, and tumor formation. To support this conclusion, we detected significant reductions in both USP10 and SIRT6 protein expression in human colon cancers. Our study discovered crosstalk between two tumor-suppressive genes in regulating cell-cycle progression and proliferation and showed that dysregulated USP10 function promotes tumorigenesis through SIRT6 degradation.

  7. Covariant Macroscopic Quantum Geometry

    CERN Document Server

    Hogan, Craig J

    2012-01-01

    A covariant noncommutative algebra of position operators is presented, and interpreted as the macroscopic limit of a geometry that describes a collective quantum behavior of the positions of massive bodies in a flat emergent space-time. The commutator defines a quantum-geometrical relationship between world lines that depends on their separation and relative velocity, but on no other property of the bodies, and leads to a transverse uncertainty of the geometrical wave function that increases with separation. The number of geometrical degrees of freedom in a space-time volume scales holographically, as the surface area in Planck units. Ongoing branching of the wave function causes fluctuations in transverse position, shared coherently among bodies with similar trajectories. The theory can be tested using appropriately configured Michelson interferometers.

  8. The macroscopic pancake bounce

    Science.gov (United States)

    Andersen Bro, Jonas; Sternberg Brogaard Jensen, Kasper; Nygaard Larsen, Alex; Yeomans, Julia M.; Hecksher, Tina

    2017-01-01

    We demonstrate that the so-called pancake bounce of millimetric water droplets on surfaces patterned with hydrophobic posts (Liu et al 2014 Nat. Phys. 10 515) can be reproduced on larger scales. In our experiment, a bed of nails plays the role of the structured surface and a water balloon models the water droplet. The macroscopic version largely reproduces the features of the microscopic experiment, including the Weber number dependence and the reduced contact time for pancake bouncing. The scalability of the experiment confirms the mechanisms of pancake bouncing, and allows us to measure the force exerted on the surface during the bounce. The experiment is simple and inexpensive and is an example where front-line research is accessible to student projects.

  9. [Role of meristem-specific genes of plants in formation of genetic tumors].

    Science.gov (United States)

    Lutova, L A; Dodueva, I E

    2007-01-01

    In higher plants, homeobox genes of the KNOX and WOX subfamilies plays a key role in maintenance of the pool of stem cells, regulate proliferation, and prevent cell differentiation. It has been shown that meristem-specific genes are regulated by phytohormones and affect their metabolism, specifically that of cytokinins. Plant tumors are widely used as a model for studying the genetic control of cell division and differentiation. The tumors induced by pathogens and genetic tumors, whose development depends on the plant genotype, are distinguished. The changes in the levels of expression of genes--regulators of cell cycle, meristem-specific genes, and genes controlling metabolism and transmission of the signal of phytohormones were described on tumors of different origin. The mechanisms underlying tumor formation in plants and animals were shown to be similar, specifically as concerns the relationship between the genes--cell cycle regulators and tumorigenesis. In plants, transcriptional factors of the subfamily KNOX have similarity in structure and, supposedly, common origin with transcriptional factors MEIS in animals, which are very active in neoplastic cells. The review presents the characteristics of KNOX and WOX transcriptional factors, their functions in meristem development, and interaction with the plant hormonal system. The role of homeodomain-containing transcriptional factors in tumorigenesis in plants and animals is discussed. The role of meristem-specific genes and phytohormones in tumorigenesis is discussed on the example of genetic tumors obtained by mutagenesis in Arabidopsis thaliana and tumors in the radish inbred lines.

  10. Enhanced tumor-targeting selectivity by modulating bispecific antibody binding affinity and format valence

    Science.gov (United States)

    Mazor, Yariv; Sachsenmeier, Kris F.; Yang, Chunning; Hansen, Anna; Filderman, Jessica; Mulgrew, Kathy; Wu, Herren; Dall’Acqua, William F.

    2017-01-01

    Bispecific antibodies are considered attractive bio-therapeutic agents owing to their ability to target two distinct disease mediators. Cross-arm avidity targeting of antigen double-positive cancer cells over single-positive normal tissue is believed to enhance the therapeutic efficacy, restrict major escape mechanisms and increase tumor-targeting selectivity, leading to reduced systemic toxicity and improved therapeutic index. However, the interplay of factors regulating target selectivity is not well understood and often overlooked when developing clinically relevant bispecific therapeutics. We show in vivo that dual targeting alone is not sufficient to endow selective tumor-targeting, and report the pivotal roles played by the affinity of the individual arms, overall avidity and format valence. Specifically, a series of monovalent and bivalent bispecific IgGs composed of the anti-HER2 trastuzumab moiety paired with affinity-modulated VH and VL regions of the anti-EGFR GA201 mAb were tested for selective targeting and eradication of double-positive human NCI-H358 non-small cell lung cancer target tumors over single-positive, non-target NCI-H358-HER2 CRISPR knock out tumors in nude mice bearing dual-flank tumor xenografts. Affinity-reduced monovalent bispecific variants, but not their bivalent bispecific counterparts, mediated a greater degree of tumor targeting selectivity, while the overall efficacy against the targeted tumor was not substantially affected. PMID:28067257

  11. Canonical quantization of macroscopic electromagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Philbin, T G, E-mail: tgp3@st-andrews.ac.u [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)

    2010-12-15

    Application of the standard canonical quantization rules of quantum field theory to macroscopic electromagnetism has encountered obstacles due to material dispersion and absorption. This has led to a phenomenological approach to macroscopic quantum electrodynamics where no canonical formulation is attempted. In this paper macroscopic electromagnetism is canonically quantized. The results apply to any linear, inhomogeneous, magnetodielectric medium with dielectric functions that obey the Kramers-Kronig relations. The prescriptions of the phenomenological approach are derived from the canonical theory.

  12. Canonical quantization of macroscopic electromagnetism

    CERN Document Server

    Philbin, T G

    2010-01-01

    Application of the standard canonical quantization rules of quantum field theory to macroscopic electromagnetism has encountered obstacles due to material dispersion and absorption. This has led to a phenomenological approach to macroscopic quantum electrodynamics where no canonical formulation is attempted. In this paper macroscopic electromagnetism is canonically quantized. The results apply to any linear, inhomogeneous, magnetoelectric medium with dielectric functions that obey the Kramers-Kronig relations. The prescriptions of the phenomenological approach are derived from the canonical theory.

  13. Genetic ablation of cyclooxygenase-2 in keratinocytes produces a cell-autonomous defect in tumor formation

    Science.gov (United States)

    Langenbach, Robert

    2012-01-01

    Using a mouse skin tumor model, we reported previously that cyclooxygenase-2 (COX-2) deficiency reduced papilloma formation. However, this model did not differentiate between the effects of systemic COX-2-deficiency and keratinocyte-specific COX-2 deficiency on tumor formation. To determine whether keratinocyte-specific COX-2 deficiency reduced papilloma formation, v-H-ras-transformed COX-2+/+ and COX-2−/− keratinocytes were grafted onto nude mice and tumor development was compared. Transformed COX-2+/+ and COX-2−/− keratinocytes expressed similar levels of H-ras, epidermal growth factor receptor and phospho-extracellular signal-regulated kinase1/2 in vitro; and COX-2-deficiency did not reduce uninfected or v-H-ras infected keratinocyte replication. In contrast, tumors arising from grafted transformed COX-2+/+ and COX-2−/− keratinocytes expressed similar levels of H-ras, but COX-2 deficiency reduced phospho-extracellular signal-regulated kinase 1/2 and epidermal growth factor receptor levels 50–60% and tumor volume by 80% at 3 weeks. Two factors appeared to account for the reduced papilloma size. First, papillomas derived from COX-2−/− keratinocytes showed about 70% decreased proliferation, as measured by bromodeoxyuridine incorporation, compared with papillomas derived from COX-2+/+ keratinocytes. Second, keratin 1 immunostaining of papillomas indicated that COX-2−/− keratinocytes prematurely initiated terminal differentiation. Differences in the levels of apoptosis and vascularization did not appear to be contributing factors as their levels were similar in tumors derived from COX-2−/− and COX-2+/+ keratinocytes. Overall, the data are in agreement with our previous observations that decreased papilloma number and size on COX-2−/− mice resulted from reduced keratinocyte proliferation and accelerated keratinocyte differentiation. Furthermore, the data indicate that deficiency/inhibition of COX-2 in the initiated keratinocyte is an

  14. Overexpression of the protein tyrosine phosphatase PRL-2 correlates with breast tumor formation and progression.

    Science.gov (United States)

    Hardy, Serge; Wong, Nau Nau; Muller, William J; Park, Morag; Tremblay, Michel L

    2010-11-01

    The PRL-1, PRL-2, and PRL-3 phosphatases are prenylated protein tyrosine phosphatases with oncogenic activity that are proposed to drive tumor metastasis. We found that PRL-2 mRNA is elevated in primary breast tumors relative to matched normal tissue, and also dramatically elevated in metastatic lymph nodes compared with primary tumors. PRL-2 knockdown in metastatic MDA-MB-231 breast cancer cells decreased anchorage-independent growth and cell migration, suggesting that the malignant phenotype of these cells is mediated at least in part through PRL-2 signaling. In different mouse mammary tumor-derived cell lines overexpressing PRL-2, we confirmed its role in anchorage-independent growth and cell migration. Furthermore, injection of PRL-2-overexpressing cells into the mouse mammary fat pad promoted extracellular signal-regulated kinase 1/2 activation and tumor formation. MMTV-PRL-2 transgenic mice engineered to overexpress the enzyme in mammary tissue did not exhibit spontaneous tumorigenesis, but they exhibited an accelerated development of mammary tumors initiated by introduction of an MMTV-ErbB2 transgene. Together, our results argue that PRL-2 plays a role in breast cancer progression.

  15. [Cancer Cells as Dynamic System - Molecular and Phenotypic Changes During Tumor Formation, Progression and Dissemination].

    Science.gov (United States)

    Sommerová, L; Ondroušková, E; Hrstka, R

    Dynamic, punctual and perfectly coordinated cellular response to internal and external stimuli is a crucial prerequisite for adaptation of mammalian cells to all changes that occur during cellular development under physiological conditions. Hijacking this ability is characteristic for tumor cells that are capable to adapt to unfavorable conditions which contribute to the formation and development of cancer during the process of tumor formation and progression. By changing key mechanisms, malignant cells can avoid cell death and thus allow development and spread of the tumor. The changes at the genetic level are manifested by various phenotypic characteristics, through which tumor cells are able to escape defense mechanisms, to acquire resistance to treatment, to invade and to create secondary tumors. In recent years, one of the most studied properties include changes in energy metabolism, when tumor cells specifically control reprogramming of the main metabolic pathways for their own benefit and to satisfy their increased needs not only for energy, but also for building materials required for increased proliferation. To adapt to extracellular conditions, it is necessary that cells undergo morphological changes, where modifications in the cell shape through reorganization of cytoskeletal filaments allow tumor cells to increase their invasiveness and other aggressive features. Clarifying these changes together with understanding of the switch in the genetic program within cancer cells, which allows them to overcome different stages of differentiation from cancer stem cells to fully differentiated cells, would be an important prerequisite for identification of the cancer cell "weaknesses" and may lead to improved cancer treatment. The ability of tumor cells to alter the rules of their own organism thus represents an important challenge for oncological research.Key words: cellular reprogramming - cancer cell plasticity - cancer metabolism - tumor heterogeneity

  16. Sequential Salinomycin Treatment Results in Resistance Formation through Clonal Selection of Epithelial-Like Tumor Cells

    Directory of Open Access Journals (Sweden)

    Florian Kopp

    2014-12-01

    Full Text Available Acquiring therapy resistance is one of the major obstacles in the treatment of patients with cancer. The discovery of the cancer stem cell (CSC–specific drug salinomycin raised hope for improved treatment options by targeting therapy-refractory CSCs and mesenchymal cancer cells. However, the occurrence of an acquired salinomycin resistance in tumor cells remains elusive. To study the formation of salinomycin resistance, mesenchymal breast cancer cells were sequentially treated with salinomycin in an in vitro cell culture assay, and the resulting differences in gene expression and salinomycin susceptibility were analyzed. We demonstrated that long-term salinomycin treatment of mesenchymal cancer cells resulted in salinomycin-resistant cells with elevated levels of epithelial markers, such as E-cadherin and miR-200c, a decreased migratory capability, and a higher susceptibility to the classic chemotherapeutic drug doxorubicin. The formation of salinomycin resistance through the acquisition of epithelial traits was further validated by inducing mesenchymal-epithelial transition through an overexpression of miR-200c. The transition from a mesenchymal to a more epithelial-like phenotype of salinomycin-treated tumor cells was moreover confirmed in vivo, using syngeneic and, for the first time, transgenic mouse tumor models. These results suggest that the acquisition of salinomycin resistance through the clonal selection of epithelial-like cancer cells could become exploited for improved cancer therapies by antagonizing the tumor-progressive effects of epithelial-mesenchymal transition.

  17. Sequential Salinomycin Treatment Results in Resistance Formation through Clonal Selection of Epithelial-Like Tumor Cells.

    Science.gov (United States)

    Kopp, Florian; Hermawan, Adam; Oak, Prajakta Shirish; Ulaganathan, Vijay Kumar; Herrmann, Annika; Elnikhely, Nefertiti; Thakur, Chitra; Xiao, Zhiguang; Knyazev, Pjotr; Ataseven, Beyhan; Savai, Rajkumar; Wagner, Ernst; Roidl, Andreas

    2014-12-01

    Acquiring therapy resistance is one of the major obstacles in the treatment of patients with cancer. The discovery of the cancer stem cell (CSC)-specific drug salinomycin raised hope for improved treatment options by targeting therapy-refractory CSCs and mesenchymal cancer cells. However, the occurrence of an acquired salinomycin resistance in tumor cells remains elusive. To study the formation of salinomycin resistance, mesenchymal breast cancer cells were sequentially treated with salinomycin in an in vitro cell culture assay, and the resulting differences in gene expression and salinomycin susceptibility were analyzed. We demonstrated that long-term salinomycin treatment of mesenchymal cancer cells resulted in salinomycin-resistant cells with elevated levels of epithelial markers, such as E-cadherin and miR-200c, a decreased migratory capability, and a higher susceptibility to the classic chemotherapeutic drug doxorubicin. The formation of salinomycin resistance through the acquisition of epithelial traits was further validated by inducing mesenchymal-epithelial transition through an overexpression of miR-200c. The transition from a mesenchymal to a more epithelial-like phenotype of salinomycin-treated tumor cells was moreover confirmed in vivo, using syngeneic and, for the first time, transgenic mouse tumor models. These results suggest that the acquisition of salinomycin resistance through the clonal selection of epithelial-like cancer cells could become exploited for improved cancer therapies by antagonizing the tumor-progressive effects of epithelial-mesenchymal transition.

  18. EGFR-STAT3 signaling promotes formation of malignant peripheral nerve sheath tumors

    OpenAIRE

    Wu, Jianqiang; Deanna M. Patmore; Jousma, Edwin; Eaves, David W.; Breving, Kimberly; Patel, Ami V.; Schwartz, Eric B.; Fuchs, James R.; Cripe, Timothy P.; Stemmer-Rachamimov, Anat O.; Ratner, Nancy

    2013-01-01

    Malignant peripheral nerve sheath tumors (MPNSTs) develop sporadically or in the context of neurofibromatosis type 1 (NF1). EGFR overexpression has been implicated in MPNST formation, but its precise role and relevant signaling pathways remain unknown. We found that EGFR overexpression promotes mouse neurofibroma transformation to aggressive MPNST (GEM-PNST). Immunohistochemistry demonstrated phosphorylated STAT3 (Tyr705) in both human MPNST and mouse GEM-PNST. A specific JAK2/STAT3 inhibitor...

  19. Formation of a Tunnel under the Major Hepatic Vein Mouths during Removal of IVC Tumor Thrombus

    Directory of Open Access Journals (Sweden)

    Dmytro Shchukin

    2013-01-01

    Full Text Available This study describes a clinical observation of successful implementation of a new surgical maneuver: formation of a cross tunnel under the mouths of the major hepatic veins during removal of a tumor thrombus of the inferior vena cava. This surgical technique helps avoid the usage of   “piggyback” mobilization of the liver and the complications associated with it. However, for objective evaluation of this approach, a further clinical study is required.

  20. Quantum equilibria for macroscopic systems

    Energy Technology Data Exchange (ETDEWEB)

    Grib, A [Department of Theoretical Physics and Astronomy, Russian State Pedagogical University, St. Petersburg (Russian Federation); Khrennikov, A [Centre for Mathematical Modelling in Physics and Cognitive Sciences Vaexjoe University (Sweden); Parfionov, G [Department of Mathematics, St. Petersburg State University of Economics and Finances (Russian Federation); Starkov, K [Department of Mathematics, St. Petersburg State University of Economics and Finances (Russian Federation)

    2006-06-30

    Nash equilibria are found for some quantum games with particles with spin-1/2 for which two spin projections on different directions in space are measured. Examples of macroscopic games with the same equilibria are given. Mixed strategies for participants of these games are calculated using probability amplitudes according to the rules of quantum mechanics in spite of the macroscopic nature of the game and absence of Planck's constant. A possible role of quantum logical lattices for the existence of macroscopic quantum equilibria is discussed. Some examples for spin-1 cases are also considered.

  1. [Formation of optimum dose fields in contact radiation therapy of malignant tumors].

    Science.gov (United States)

    Klepper, L Ia

    2003-01-01

    The definition of the homogeneity of a dose field in the contact radiation therapy for malignant tumors is introduced. The mathematical interpretation of problems in the formation of optimum dose fields, to which the maximum homogeneity of a dose field at the site of lesion corresponds, is presented. It is shown that the problems in the formation of optimum dose fields may be divided into two subsets in relation to whether the sources of radiation are located at the site of lesion or adjacent to the latter (application techniques of radiation). An analytical method for solving a problem in the formation of an optimal dose field in the ring circle by means of one ring source of radiation (the first type of problems). The investigation was conducted with the support of the Russian Fund of Fundamental Investigations (RFFI 01-01-00137).

  2. LIN28: A Stem Cell Factor with a Key Role in Pediatric Tumor Formation.

    Science.gov (United States)

    Carmel-Gross, Ilana; Bollag, Naomi; Armon, Leah; Urbach, Achia

    2016-03-01

    Differentiation and development are normally unidirectional processes in which progenitor/stem cells differentiate into more mature cells. Transformation of adult cells into cancer cells is accompanied in many cases by dedifferentiation of the adult cell, while differentiation failure of progenitor cells can result in the formation of unique type of cancers called pediatric cancer. LIN28A and its paralog LIN28B are pluripotent genes that are expressed mainly in stem/progenitor cells. Since the first identification of LIN28 in mammals, numerous studies demonstrated the general oncogenic features of these genes. In this review, we emphasize the unique role of LIN28 in pediatric tumor formation. We show, based on comprehensive literature screen and analysis of published microarray data, that LIN28 expression in pediatric tumors is even more common than in adult tumors, and discuss the possibility that in the case of pediatric cancers, LIN28 acts by preventing normal development/differentiation rather than by transformation of mature cells into cancer cells. Overall, this review highlights the role of LIN28 as a bridge point between embryonic development, stem cell biology, and cancer.

  3. Inhibition of proliferation by PERK regulates mammary acinar morphogenesis and tumor formation.

    Directory of Open Access Journals (Sweden)

    Sharon J Sequeira

    Full Text Available Endoplasmic reticulum (ER stress signaling can be mediated by the ER kinase PERK, which phosphorylates its substrate eIF2alpha. This in turn, results in translational repression and the activation of downstream programs that can limit cell growth through cell cycle arrest and/or apoptosis. These responses can also be initiated by perturbations in cell adhesion. Thus, we hypothesized that adhesion-dependent regulation of PERK signaling might determine cell fate. We tested this hypothesis in a model of mammary acini development, a morphogenetic process regulated in part by adhesion signaling. Here we report a novel role for PERK in limiting MCF10A mammary epithelial cell proliferation during acinar morphogenesis in 3D Matrigel culture as well as in preventing mammary tumor formation in vivo. We show that loss of adhesion to a suitable substratum induces PERK-dependent phosphorylation of eIF2alpha and selective upregulation of ATF4 and GADD153. Further, inhibition of endogenous PERK signaling during acinar morphogenesis, using two dominant-negative PERK mutants (PERK-DeltaC or PERK-K618A, does not affect apoptosis but results instead in hyper-proliferative and enlarged lumen-filled acini, devoid of proper architecture. This phenotype correlated with an adhesion-dependent increase in translation initiation, Ki67 staining and upregulation of Laminin-5, ErbB1 and ErbB2 expression. More importantly, the MCF10A cells expressing PERKDeltaC, but not a vector control, were tumorigenic in vivo upon orthotopic implantation in denuded mouse mammary fat pads. Our results reveal that the PERK pathway is responsive to adhesion-regulated signals and that it is essential for proper acinar morphogenesis and in preventing mammary tumor formation. The possibility that deficiencies in PERK signaling could lead to hyperproliferation of the mammary epithelium and increase the likelihood of tumor formation, is of significance to the understanding of breast cancer.

  4. A GATA4-regulated tumor suppressor network represses formation of malignant human astrocytomas

    Science.gov (United States)

    Agnihotri, Sameer; Wolf, Amparo; Munoz, Diana M.; Smith, Christopher J.; Gajadhar, Aaron; Restrepo, Andres; Clarke, Ian D.; Fuller, Gregory N.; Kesari, Santosh; Dirks, Peter B.; McGlade, C. Jane; Stanford, William L.; Aldape, Kenneth; Mischel, Paul S.; Hawkins, Cynthia

    2011-01-01

    Glioblastoma Multiforme (GBM), the most common and lethal primary human brain tumor, exhibits multiple molecular aberrations. We report that loss of the transcription factor GATA4, a negative regulator of normal astrocyte proliferation, is a driver in glioma formation and fulfills the hallmarks of a tumor suppressor gene (TSG). Although GATA4 was expressed in normal brain, loss of GATA4 was observed in 94/163 GBM operative samples and was a negative survival prognostic marker. GATA4 loss occurred through promoter hypermethylation or novel somatic mutations. Loss of GATA4 in normal human astrocytes promoted high-grade astrocytoma formation, in cooperation with other relevant genetic alterations such as activated Ras or loss of TP53. Loss of GATA4 with activated Ras in normal astrocytes promoted a progenitor-like phenotype, formation of neurospheres, and the ability to differentiate into astrocytes, neurons, and oligodendrocytes. Re-expression of GATA4 in human GBM cell lines, primary cultures, and brain tumor–initiating cells suppressed tumor growth in vitro and in vivo through direct activation of the cell cycle inhibitor P21CIP1, independent of TP53. Re-expression of GATA4 also conferred sensitivity of GBM cells to temozolomide, a DNA alkylating agent currently used in GBM therapy. This sensitivity was independent of MGMT (O-6-methylguanine-DNA-methyltransferase), the DNA repair enzyme which is often implicated in temozolomide resistance. Instead, GATA4 reduced expression of APNG (alkylpurine-DNA-N-glycosylase), a DNA repair enzyme which is poorly characterized in GBM-mediated temozolomide resistance. Identification and validation of GATA4 as a TSG and its downstream targets in GBM may yield promising novel therapeutic strategies. PMID:21464220

  5. Tumor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008479 Preliminary study of MR elastography in brain tumors. XU Lei(徐磊), et al.Neurosci Imaging Center, Beijing Tiantan Hosp, Capital Med Univ, Beijing 100050.Chin J Radiol 2008;42(6):605-608. Objective To investigate the potential values of magnetic resonance elastography (MRE) for evaluating the brain tumor consistency in vivo. Methods Fourteen patients with known solid brain tumor (5 male, 9 female; age range: 16-63 years)

  6. alpha-Lactalbumin species variation, HAMLET formation, and tumor cell death.

    Science.gov (United States)

    Pettersson, Jenny; Mossberg, Ann-Kristin; Svanborg, Catharina

    2006-06-23

    HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a tumoricidal complex of apo alpha-lactalbumin and oleic acid, formed in casein after low pH treatment of human milk. This study examined if HAMLET-like complexes are present in casein from different species and if isolated alpha-lactalbumin from those species can form such complexes with oleic acid. Casein from human, bovine, equine, and porcine milk was separated by ion exchange chromatography and active complexes were only found in human casein. This was not explained by alpha-lactalbumin sequence variation, as purified bovine, equine, porcine, and caprine alpha-lactalbumins formed complexes with oleic acid with biological activity similar to HAMLET. We conclude that structural variation of alpha-lactalbumins does not preclude the formation of HAMLET-like complexes and that natural HAMLET formation in casein was unique to human milk, which also showed the highest oleic acid content.

  7. Macroscopic-microscopic mass models

    CERN Document Server

    Nix, J R; Nix, J Rayford; Moller, Peter

    1995-01-01

    We discuss recent developments in macroscopic-microscopic mass models, including the 1992 finite-range droplet model, the 1992 extended-Thomas-Fermi Strutinsky-integral model, and the 1994 Thomas-Fermi model, with particular emphasis on how well they extrapolate to new regions of nuclei. We also address what recent developments in macroscopic-microscopic mass models are teaching us about such physically relevant issues as the nuclear curvature energy, a new congruence energy arising from a greater-than-average overlap of neutron and proton wave functions, the nuclear incompressibility coefficient, and the Coulomb redistribution energy arising from a central density depression. We conclude with a brief discussion of the recently discovered rock of metastable superheavy nuclei near 272:110 that had been correctly predicted by macroscopic-microscopic models, along with a possible new tack for reaching an island near 290:110 beyond our present horizon.

  8. Role of Tertiary Lymphoid Structures (TLS) in Anti-Tumor Immunity: Potential Tumor-Induced Cytokines/Chemokines that Regulate TLS Formation in Epithelial-Derived Cancers

    Energy Technology Data Exchange (ETDEWEB)

    Pimenta, Erica M. [Rutgers Biomedical and Health Sciences, New Jersey Medical School-Cancer Center, Newark, NJ 07103 (United States); Barnes, Betsy J., E-mail: barnesbe@njms.rutgers.edu [Department of Biochemistry and Molecular Biology, Rutgers Biomedical and Health Sciences, New Jersey Medical School-Cancer Center, Newark, NJ 07103 (United States)

    2014-04-23

    Following the successes of monoclonal antibody immunotherapies (trastuzumab (Herceptin{sup ®}) and rituximab (Rituxan{sup ®})) and the first approved cancer vaccine, Provenge{sup ®} (sipuleucel-T), investigations into the immune system and how it can be modified by a tumor has become an exciting and promising new field of cancer research. Dozens of clinical trials for new antibodies, cancer and adjuvant vaccines, and autologous T and dendritic cell transfers are ongoing in hopes of identifying ways to re-awaken the immune system and force an anti-tumor response. To date, however, few consistent, reproducible, or clinically-relevant effects have been shown using vaccine or autologous cell transfers due in part to the fact that the immunosuppressive mechanisms of the tumor have not been overcome. Much of the research focus has been on re-activating or priming cytotoxic T cells to recognize tumor, in some cases completely disregarding the potential roles that B cells play in immune surveillance or how a solid tumor should be treated to maximize immunogenicity. Here, we will summarize what is currently known about the induction or evasion of humoral immunity via tumor-induced cytokine/chemokine expression and how formation of tertiary lymphoid structures (TLS) within the tumor microenvironment may be used to enhance immunotherapy response.

  9. Role of Tertiary Lymphoid Structures (TLS in Anti-Tumor Immunity: Potential Tumor-Induced Cytokines/Chemokines that Regulate TLS Formation in Epithelial-Derived Cancers

    Directory of Open Access Journals (Sweden)

    Erica M. Pimenta

    2014-04-01

    Full Text Available Following the successes of monoclonal antibody immunotherapies (trastuzumab (Herceptin® and rituximab (Rituxan® and the first approved cancer vaccine, Provenge® (sipuleucel-T, investigations into the immune system and how it can be modified by a tumor has become an exciting and promising new field of cancer research. Dozens of clinical trials for new antibodies, cancer and adjuvant vaccines, and autologous T and dendritic cell transfers are ongoing in hopes of identifying ways to re-awaken the immune system and force an anti-tumor response. To date, however, few consistent, reproducible, or clinically-relevant effects have been shown using vaccine or autologous cell transfers due in part to the fact that the immunosuppressive mechanisms of the tumor have not been overcome. Much of the research focus has been on re-activating or priming cytotoxic T cells to recognize tumor, in some cases completely disregarding the potential roles that B cells play in immune surveillance or how a solid tumor should be treated to maximize immunogenicity. Here, we will summarize what is currently known about the induction or evasion of humoral immunity via tumor-induced cytokine/chemokine expression and how formation of tertiary lymphoid structures (TLS within the tumor microenvironment may be used to enhance immunotherapy response.

  10. A simple and effective approach for treatment of situs tumor and metastasis:to promote intratumor pus formation

    Directory of Open Access Journals (Sweden)

    Hong Li

    2015-12-01

    Full Text Available Purpose: The recent emergence of the tumor microenvironment as the critical determinant in cancer outcome opens a new routes to fight cancer, however, the clinical results of targeting microenvironment for treating human cancer have not met expectations. Our purpose is to investigate how to target microenvironment for treatment of situs tumor and metastasis.Methods : We suppose that tumor is a robber from times of anarchy and disorder and can be eradicated in flourishing age. We also suppose that carcinogenesis is largely attributed to physically weak that cann’t get rid of ulcer by pus formation. In vivo,the subcutaneous implant model and pulmonary metastasis model of lewis lung cancer were established. Tumor bearing mice were taken water decoction of Astragalus mongholicus(huangqi and Spina Gleditsiae (zaojiaoci by intragastric administration b.i.d for ten weeks, and the influences of Astragalus mongholicus and Spina Gleditsiae  on tumor progression were evaluated by body temperature,blood oxygen saturation,red cell ATPase,blood  rheology,intratumor hypoxia,capillary permeability, matrix metalloproteinase (MMPs and intratumor pus formation.  Results:We found that both of Astragalus mongholicus and Spina Gleditsiae could keep body temperature,blood oxygen saturation,red cell ATPase and blood rheology,and improve intratumor hypoxia,capillary permeability and MMPs in tumor bearing mice,which led to slower tumor growth and less metastasis. Astragalus mongholicus could remove body poison and stimulate immune responses, and Spina Gleditsiae  could  promote pus formation and proteolytic enzymes. The combination of  Astragalus mongholicus and Spina Gleditsiae favored the restoration of tumor immune responses and proteolytic activity at the tumor site, which not only result to an increase in aseptic pus formation, but also to a decrease in necrotic tissue accumulation, and finally caused a complete intratumor pus

  11. EXPRESSION OF SV40 Tag AND FORMATION Tag-p53 AND Tag-Rb COMPLEXES IN CHINESE BRAIN TUMORS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To investigate the expression of SV40 Tag andformation of Tag-p53 and Tag-Rb complexes in Chinese brain tumors. Methods: SV40 large tumor antigen (Tag) were investigated by immunoprecipitation, silver staining and Western blot in 65 cases of Chinese brain tumors and 8 cases of normal brain tissues. Tag-p53 and Tag-Rb complexes were screened by the same way in 20 and 15 Tag positive tumor tissues respectively. Results: Tag was found in all of 8 ependymomas and 2 choroid plexus papillomas, 90% (9/10) of pituitary adenomas, 73% (11/15) of astrocytomas, 70% (7/10) of meningiomas, 50% (4/8) of glioblastoma multiform, 33% (2/6) of medulloblastomas, 5 oligodendrogliomas, 1 pineocytoma and 8 normal brain tissues were negative for Tag. Tag-p53 complex was detected in all of 20 Tag positive tumors as well as Tag-Rb complex in all of 15 Tag positive tumors. Conclusion: SV40 Tag is not only expressed in human brain tumors, but also it can form specific complexes with tumor suppressors p53 and Rb. SV40 is correlated to human brain tumorigenesis. The inactivation of p53 and Rb due to the formation of Tag-p53 and Tag-Rb complexes is possibly an important mechanism in the etiopathogenesis of human brain tumors.

  12. The tumor suppressor PTEN and the PDK1 kinase regulate formation of the columnar neural epithelium.

    Science.gov (United States)

    Grego-Bessa, Joaquim; Bloomekatz, Joshua; Castel, Pau; Omelchenko, Tatiana; Baselga, José; Anderson, Kathryn V

    2016-01-26

    Epithelial morphogenesis and stability are essential for normal development and organ homeostasis. The mouse neural plate is a cuboidal epithelium that remodels into a columnar pseudostratified epithelium over the course of 24 hr. Here we show that the transition to a columnar epithelium fails in mutant embryos that lack the tumor suppressor PTEN, although proliferation, patterning and apical-basal polarity markers are normal in the mutants. The Pten phenotype is mimicked by constitutive activation of PI3 kinase and is rescued by the removal of PDK1 (PDPK1), but does not depend on the downstream kinases AKT and mTORC1. High resolution imaging shows that PTEN is required for stabilization of planar cell packing in the neural plate and for the formation of stable apical-basal microtubule arrays. The data suggest that appropriate levels of membrane-associated PDPK1 are required for stabilization of apical junctions, which promotes cell elongation, during epithelial morphogenesis.

  13. Epithelial membrane protein-2 promotes endometrial tumor formation through activation of FAK and Src.

    Directory of Open Access Journals (Sweden)

    Maoyong Fu

    Full Text Available Endometrial cancer is the most common gynecologic malignancy diagnosed among women in developed countries. One recent biomarker strongly associated with disease progression and survival is epithelial membrane protein-2 (EMP2, a tetraspan protein known to associate with and modify surface expression of certain integrin isoforms. In this study, we show using a xenograft model system that EMP2 expression is necessary for efficient endometrial tumor formation, and we have started to characterize the mechanism by which EMP2 contributes to this malignant phenotype. In endometrial cancer cells, the focal adhesion kinase (FAK/Src pathway appears to regulate migration as measured through wound healing assays. Manipulation of EMP2 levels in endometrial cancer cells regulates the phosphorylation of FAK and Src, and promotes their distribution into lipid raft domains. Notably, cells with low levels of EMP2 fail to migrate and poorly form tumors in vivo. These findings reveal the pivotal role of EMP2 in endometrial cancer carcinogenesis, and suggest that the association of elevated EMP2 levels with endometrial cancer prognosis may be causally linked to its effect on integrin-mediated signaling.

  14. Humanized mouse model of ovarian cancer recapitulates patient solid tumor progression, ascites formation, and metastasis.

    Directory of Open Access Journals (Sweden)

    Richard B Bankert

    Full Text Available Ovarian cancer is the most common cause of death from gynecological cancer. Understanding the biology of this disease, particularly how tumor-associated lymphocytes and fibroblasts contribute to the progression and metastasis of the tumor, has been impeded by the lack of a suitable tumor xenograft model. We report a simple and reproducible system in which the tumor and tumor stroma are successfully engrafted into NOD-scid IL2Rγ(null (NSG mice. This is achieved by injecting tumor cell aggregates derived from fresh ovarian tumor biopsy tissues (including tumor cells, and tumor-associated lymphocytes and fibroblasts i.p. into NSG mice. Tumor progression in these mice closely parallels many of the events that are observed in ovarian cancer patients. Tumors establish in the omentum, ovaries, liver, spleen, uterus, and pancreas. Tumor growth is initially very slow and progressive within the peritoneal cavity with an ultimate development of tumor ascites, spontaneous metastasis to the lung, increasing serum and ascites levels of CA125, and the retention of tumor-associated human fibroblasts and lymphocytes that remain functional and responsive to cytokines for prolonged periods. With this model one will be able to determine how fibroblasts and lymphocytes within the tumor microenvironment may contribute to tumor growth and metastasis, and will make it possible to evaluate the efficacy of therapies that are designed to target these cells in the tumor stroma.

  15. Tumor necrosis factor- α infliximab inhibits osteoclast formation of peripheral blood mononuclear cells but does not affect periodontal ligament fibroblast-mediated osteoclast formation

    NARCIS (Netherlands)

    de Vries, T.J.; Yousovich, J.; Schoenmaker, T.; Scheres, N.; Everts, V.

    2016-01-01

    Background and Objective: The inflammatory cytokine tumor necrosis factor-alpha (TNF-α) is elevated in inflamed periodontal tissues and may contribute to periodontitis progression. TNF-α stimulates formation and activity of osteoclasts, the cells that are recruited in periodontitis, that cause alveo

  16. Photoinduced macroscopic chiral structures in a series of azobenzene copolyesters

    DEFF Research Database (Denmark)

    Nedelchev, L.; Nikolova, L.; Matharu, A.

    2002-01-01

    A study of the propagation of elliptically polarized light and the resulting formation of macroscopic chiral structures in a series of azobenzene side-chain copolyesters, in which the morphology is varied from liquid crystalline to amorphous, is reported. Real-time measurements are presented...

  17. The postischemic environment differentially impacts teratoma or tumor formation after transplantation of human embryonic stem cell-derived neural progenitors

    DEFF Research Database (Denmark)

    Seminatore, Christine; Polentes, Jerome; Ellman, Ditte

    2010-01-01

    Risk of tumorigenesis is a major obstacle to human embryonic and induced pluripotent stem cell therapy. Likely linked to the stage of differentiation of the cells at the time of implantation, formation of teratoma/tumors can also be influenced by factors released by the host tissue. We have...... analyzed the relative effects of the stage of differentiation and the postischemic environment on the formation of adverse structures by transplanted human embryonic stem cell-derived neural progenitors....

  18. SIRT1 catalytic activity has little effect on tumor formation and metastases in a mouse model of breast cancer.

    Directory of Open Access Journals (Sweden)

    Katherine V Clark-Knowles

    Full Text Available The protein deacetylase SIRT1 has been implicated in the regulation of a large number of cellular processes that are thought to be required for cancer initiation and progression. There are conflicting data that make it unclear whether Sirt1 functions as an oncogene or tumor suppressor. To assess the effect of SIRT1 on the emergence and progression of mammary tumors, we crossed mice that harbor a point mutation that abolishes SIRT1 catalytic activity with mice carrying the polyoma middle T transgene driven by the murine mammary tumor virus promoter (MMTV-PyMT. The absence of SIRT1 catalytic activity neither accelerated nor blocked the formation of tumors and metastases in this model. There was a lag in tumor latency that modestly extended survival in Sirt1 mutant mice that we attribute to a delay in mammary gland development and not to a direct effect of SIRT1 on carcinogenesis. These results are consistent with previous evidence suggesting that Sirt1 is not a tumor promoter or a tumor suppressor.

  19. Tumor abscess formation caused by Morganella morganii complicated with bacteremia in a patient with gastrointestinal stromal tumor.

    Science.gov (United States)

    Chen, Hsuan-Wei; Lin, Te-Yu

    2012-04-01

    We report the case of a 22-year-old man who presented with a 3-day history of watery diarrhea, abdominal pain, and fever. An image of the abdomen showed a heterogeneously echogenic mass lesion in the pelvis. The results of the blood cultures performed on admission showed the presence of Morganella morganii. Computed tomography-guided tube drainage was performed, and a culture of the drained abscess fluid yielded M. morganii growth. Exploratory laparotomy with segmental resection of the jejunum and excision of the tumor was performed. Pathological examination showed a gastrointestinal stromal tumor (GIST). A GIST abscess caused by M. morganii was diagnosed on the basis of radiological, microbiological, and histopathological findings. The possibility of an infected GIST should be considered during the differential diagnosis of patients with suspected abdominal neoplasm and bacteremia.

  20. The quantum interaction of macroscopic objects and gravitons

    Science.gov (United States)

    Piran, Tsvi

    2016-09-01

    Copious production of gravitational radiation requires a compact source that moves relativistically. Such sources are rare and are found only in extreme cases such as the formation of a black hole in either via a gravitational collapse or via a merger. Noncompact, nonrelativistic objects emit gravitational radiation, however, this emission is extremely weak due to very large value of the Planck energy. The quantum nature of gravitons, namely the fact that a single graviton carries energy of order ℏω implies that macroscopic objects whose kinetic energy is less than the Planck energy emit gravitons quantum mechanically, emitting a single graviton at a time. This is a unique situation in which a macroscopic object behaves quantum mechanically. While it is impossible to check experimentally this quantum gravitational effect, it might be possible to carry out analogous electromagnetic experiments that will shed light on this macroscopic quantum mechanical behavior.

  1. Macroscopic Theory of Dark Sector

    Directory of Open Access Journals (Sweden)

    Boris E. Meierovich

    2014-01-01

    Full Text Available A simple Lagrangian with squared covariant divergence of a vector field as a kinetic term turned out to be an adequate tool for macroscopic description of the dark sector. The zero-mass field acts as the dark energy. Its energy-momentum tensor is a simple additive to the cosmological constant. Massive fields describe two different forms of dark matter. The space-like massive vector field is attractive. It is responsible for the observed plateau in galaxy rotation curves. The time-like massive field displays repulsive elasticity. In balance with dark energy and ordinary matter it provides a four-parametric diversity of regular solutions of the Einstein equations describing different possible cosmological and oscillating nonsingular scenarios of evolution of the Universe. In particular, the singular big bang turns into a regular inflation-like transition from contraction to expansion with the accelerated expansion at late times. The fine-tuned Friedman-Robertson-Walker singular solution is a particular limiting case at the lower boundary of existence of regular oscillating solutions in the absence of vector fields. The simplicity of the general covariant expression for the energy-momentum tensor allows displaying the main properties of the dark sector analytically. Although the physical nature of dark sector is still unknown, the macroscopic theory can help analyze the role of dark matter in astrophysical phenomena without resorting to artificial model assumptions.

  2. Macroscopically-Discrete Quantum Cosmology

    CERN Document Server

    Chew, Geoffrey F

    2008-01-01

    To Milne's Lorentz-group-based spacetime and Gelfand-Naimark unitary representations of this group we associate a Fock space of 'cosmological preons'-quantum-theoretic universe constituents. Milne's 'cosmological principle' relies on Lorentz invariance of 'age'--global time. We divide Milne's spacetime into 'slices' of fixed macroscopic width in age, with 'cosmological rays' defined on (hyperbolic) slice boundaries-Fock space attaching only to these exceptional universe ages. Each (fixed-age) preon locates within a 6-dimensional manifold, one of whose 3 'extra' dimensions associates in Dirac sense to a self-adjoint operator that represents preon (continuous) local time, the operator canonically-conjugate thereto representing preon (total) energy. Self-adjoint-operator expectations at any spacetime-slice boundary prescribe throughout the following slice a non-fluctuating 'mundane reality'- electromagnetic and gravitational potentials 'tethered' to current densities of locally-conserved electric charge and ener...

  3. Seismic scanning tunneling macroscope - Theory

    KAUST Repository

    Schuster, Gerard T.

    2012-09-01

    We propose a seismic scanning tunneling macroscope (SSTM) that can detect the presence of sub-wavelength scatterers in the near-field of either the source or the receivers. Analytic formulas for the time reverse mirror (TRM) profile associated with a single scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the point scatterer is in the near-field region; if the sub-wavelength scatterer is a spherical impedance discontinuity then the resolution will also be limited by the radius of the sphere. Therefore, superresolution imaging can be achieved as the scatterer approaches the source. This is analogous to an optical scanning tunneling microscope that has sub-wavelength resolution. Scaled to seismic frequencies, it is theoretically possible to extract 100 Hz information from 20 Hz data by imaging of near-field seismic energy.

  4. CD44 enhances tumor formation and lung metastasis in experimental osteosarcoma and is an additional predictor for poor patient outcome.

    Science.gov (United States)

    Gvozdenovic, Ana; Arlt, Matthias J E; Campanile, Carmen; Brennecke, Patrick; Husmann, Knut; Li, Yufei; Born, Walter; Muff, Roman; Fuchs, Bruno

    2013-04-01

    Formation of metastases in the lungs is the major cause of death in patients suffering from osteosarcoma (OS). Metastases at presentation and poor response to preoperative chemotherapy are strong predictors for poor patient outcome. The elucidation of molecular markers that promote metastasis formation and/or chemoresistance is therefore of importance. CD44 is a plasma membrane glycoprotein that binds to the extracellular matrix component hyaluronan (HA) and has been shown to be involved in metastasis formation in a variety of other tumors. Here we investigated the role of CD44 expression on OS tumor formation and metastasis. High CD44 expression, evaluated with a tissue microarray including samples from 53 OS patients and stained with a pan-CD44 antibody (Hermes3), showed a tendency (p lung metastases and high CD44 expression had significantly poorer prognosis than patients with low CD44 expression. Overexpression of the standard CD44 isoform (CD44s) and its HA-binding defective mutant R41A in osteoblastic SaOS-2 cells resulted in HA-independent higher migration rates and increased chemoresistance, partially dependent on HA. In an orthotopic mouse model of OS, overexpression of CD44s in SaOS-2 cells resulted in an HA-dependent increased primary tumor formation and increased numbers of micrometastases and macrometastases in the lungs. In conclusion, although CD44 failed to be an independent predictor for patient outcome in this limited cohort of OS patients, increased CD44 expression was associated with even worse survival in patients with chemoresistance and with lung metastases. CD44-associated chemoresistance was also observed in vitro, and increased formation of lung metastases was found in vivo in SCID mice. Copyright © 2013 American Society for Bone and Mineral Research.

  5. Effects of diet-induced obesity on colitis-associated colon tumor formation in A/J mice.

    Science.gov (United States)

    Park, S-Y; Kim, J-S; Seo, Y-R; Sung, M-K

    2012-02-01

    Studies have indicated that obesity is associated with a higher risk of colorectal cancer. This study was performed to determine the effect of diet-induced obesity on the formation of azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon tumors and to identify adiposity-related mechanisms. Male A/J mice were placed on either a high-fat diet (HFD; 45% of total calories from fat) or a normal diet (ND; 15% of calories from fat) for 12 weeks. To induce colon tumors, AOM was administered at a dose of 10 mg/kg body weight, followed by two cycles of DSS supply. Study results indicated that the HFD group had twofold higher numbers of colonic tumors, as compared with the ND group. The HFD group also had significantly increased body weight and epididymal fat weight, which were associated with increases of serum insulin, insulin-like growth factor-1, leptin, epididymal fat pad leptin mRNA and colonic leptin receptor (Ob-R) mRNA. Animals on HFD showed higher expressions of Ob-R, insulin receptor, phosphorylated Akt, phosphorylated extracellular signal-regulated kinases, Bcl-xL and Cyclin D1 proteins in the colon. The results suggest that HFD-induced obesity facilitates colon tumor formation, possibly by regulating downstream targets of circulating adiposity-related factors via receptor-mediated signaling of the phosphatidylinositol 3-kinase/Akt pathway.

  6. Survivin Modulates Squamous Cell Carcinoma-Derived Stem-Like Cell Proliferation, Viability and Tumor Formation in Vivo

    Directory of Open Access Journals (Sweden)

    Roberta Lotti

    2016-01-01

    Full Text Available Squamous Cell Carcinoma-derived Stem-like Cells (SCC-SC originate from alterations in keratinocyte stem cells (KSC gene expression and sustain tumor development, invasion and recurrence. Since survivin, a KSC marker, is highly expressed in SCC-SC, we evaluate its role in SCC-SC cell growth and SCC models. Survivin silencing by siRNA decreases clonal growth of SCC keratinocytes and viability of total, rapidly adhering (RAD and non-RAD (NRAD cells from primary SCC. Similarly, survivin silencing reduces the expression of stem cell markers (OCT4, NOTCH1, CD133, β1-integrin, while it increases the level of differentiation markers (K10, involucrin. Moreover, survivin silencing improves the malignant phenotype of SCC 3D-reconstruct, as demonstrated by reduced epidermal thickness, lower Ki-67 positive cell number, and decreased expression of MMP9 and psoriasin. Furthermore, survivin depletion by siRNA in RasG12V-IκBα-derived tumors leads to smaller tumor formation characterized by lower mitotic index and reduced expression of the tumor-associated marker HIF1α, VEGF and CD51. Therefore, our results indicate survivin as a key gene in regulating SCC cancer stem cell formation and cSCC development.

  7. Expression of B-RAF V600E in type II pneumocytes causes abnormalities in alveolar formation, airspace enlargement and tumor formation in mice.

    Directory of Open Access Journals (Sweden)

    Emanuele Zanucco

    Full Text Available Growth factor induced signaling cascades are key regulatory elements in tissue development, maintenance and regeneration. Perturbations of these cascades have severe consequences, leading to developmental disorders and neoplastic diseases. As a major function in signal transduction, activating mutations in RAF family kinases are the cause of human tumorigenesis, where B-RAF V600E has been identified as the prevalent mutant. In order to address the oncogenic function of B-RAF V600E, we have generated transgenic mice expressing the activated oncogene specifically in lung alveolar epithelial type II cells. Constitutive expression of B-RAF V600E caused abnormalities in alveolar epithelium formation that led to airspace enlargements. These lung lesions showed signs of tissue remodeling and were often associated with chronic inflammation and low incidence of lung tumors. The inflammatory cell infiltration did not precede the formation of the lung lesions but was rather accompanied with late tumor development. These data support a model where the continuous regenerative process initiated by oncogenic B-RAF-driven alveolar disruption provides a tumor-promoting environment associated with chronic inflammation.

  8. Isolation and Characterization of Squamous Cell Carcinoma-Derived Stem-like Cells: Role in Tumor Formation

    Directory of Open Access Journals (Sweden)

    Carlo Pincelli

    2013-09-01

    Full Text Available In human epidermis, keratinocyte stem cells (KSC are characterized by high levels of β1-integrin, resulting in the rapid adhesion to type IV collagen. Since epithelial tumors originate from KSC, we evaluated the features of rapidly adhering (RAD keratinocytes derived from primary human squamous cell carcinoma of the skin (cSCC. RAD cells expressed higher levels of survivin, a KSC marker, as compared to non-rapidly adhering (NRAD cells. Moreover, RAD cells proliferated to a greater extent and were more efficient in forming colonies than NRAD cells. RAD cells also migrated significantly better than NRAD cells. When seeded in a silicone chamber and grafted onto the back skin of NOD SCID mice, RAD cells formed tumors 2–4 fold bigger than those derived from NRAD cells. In tumors derived from RAD cells, the mitotic index was significantly higher than in those derived from NRAD cells, while Ki-67 and survivin expression were more pronounced in RAD tumors. This study suggests that SCC RAD stem cells play a critical role in the formation and development of epithelial tumors.

  9. Isolation and characterization of squamous cell carcinoma-derived stem-like cells: role in tumor formation.

    Science.gov (United States)

    Dallaglio, Katiuscia; Petrachi, Tiziana; Marconi, Alessandra; Truzzi, Francesca; Lotti, Roberta; Saltari, Annalisa; Morandi, Paolo; Puviani, Mario; Maiorana, Antonino; Roop, Dennis R; Pincelli, Carlo

    2013-09-26

    In human epidermis, keratinocyte stem cells (KSC) are characterized by high levels of β1-integrin, resulting in the rapid adhesion to type IV collagen. Since epithelial tumors originate from KSC, we evaluated the features of rapidly adhering (RAD) keratinocytes derived from primary human squamous cell carcinoma of the skin (cSCC). RAD cells expressed higher levels of survivin, a KSC marker, as compared to non-rapidly adhering (NRAD) cells. Moreover, RAD cells proliferated to a greater extent and were more efficient in forming colonies than NRAD cells. RAD cells also migrated significantly better than NRAD cells. When seeded in a silicone chamber and grafted onto the back skin of NOD SCID mice, RAD cells formed tumors 2-4 fold bigger than those derived from NRAD cells. In tumors derived from RAD cells, the mitotic index was significantly higher than in those derived from NRAD cells, while Ki-67 and survivin expression were more pronounced in RAD tumors. This study suggests that SCC RAD stem cells play a critical role in the formation and development of epithelial tumors.

  10. Spontaneous formation of tumorigenic hybrids between breast cancer and multipotent stromal cells is a source of tumor heterogeneity.

    Science.gov (United States)

    Rappa, Germana; Mercapide, Javier; Lorico, Aurelio

    2012-06-01

    Breast cancer progression involves cancer cell heterogeneity, with generation of invasive/metastatic breast cancer cells within populations of nonmetastatic cells of the primary tumor. Sequential genetic mutations, epithelial-to-mesenchymal transition, interaction with local stroma, and formation of hybrids between cancer cells and normal bone marrow-derived cells have been advocated as tumor progression mechanisms. We report herein the spontaneous in vitro formation of heterotypic hybrids between human bone marrow-derived multipotent stromal cells (MSCs) and two different breast carcinoma cell lines, MDA-MB-231 (MDA) and MA11. Hybrids showed predominantly mesenchymal morphological characteristics, mixed gene expression profiles, and increased DNA ploidy. Both MA11 and MDA hybrids were tumorigenic in immunodeficient mice, and some MDA hybrids had an increased metastatic capacity. Both in culture and as xenografts, hybrids underwent DNA ploidy reduction and morphological reversal to breast carcinoma-like morphological characteristics, while maintaining a mixed breast cancer-mesenchymal expression profile. Analysis of coding single-nucleotide polymorphisms by RNA sequencing revealed genetic contributions from both parental partners to hybrid tumors and metastasis. Because MSCs migrate and localize to breast carcinoma, our findings indicate that formation of MSC-breast cancer cell hybrids is a potential mechanism of the generation of invasive/metastatic breast cancer cells. Our findings reconcile the fusion theory of cancer progression with the common observation that breast cancer metastases are generally aneuploid, but not tetraploid, and are histopathologically similar to the primary neoplasm.

  11. Malignant tumor formation at the site of previously irradiated acanthomatous epulides in four dogs

    Energy Technology Data Exchange (ETDEWEB)

    Thrall, D.E.; Goldschmidt, M.H.; Biery, D.N.

    1981-01-15

    The radiation response of acanthomatous epulis in 32 dogs was good, with an estimated median survival time of 21 months. Of the 32 patients, 14 have died. In 4 of those 14, malignant tumors developed at the site of the acanthomatous epulis. The tumors were of epithelial origin in 3 patients and of mesenchymal origin in 1 patient. Possibilities explaining the appearance of the malignancies included spontaneous malignant transformation, radiation induction of neoplasms, and radiation induction of malignant transformation. This uncommon complication was not considered contradictory to radiotherapy of acanthomatous epulides, because of their excellent response to irradiation and the long latent period between irradiation and appearance of the malignant tumor.

  12. Macroscopic theory of dark sector

    CERN Document Server

    Meierovich, Boris E

    2013-01-01

    A simple Lagrangian with squared covariant divergence of a vector field as a kinetic term turned out an adequate tool for macroscopic description of the dark sector. The zero-mass field acts as the dark energy. Its energy-momentum tensor is a simple additive to the cosmological constant. Massive fields {\\phi}_{I} with {\\phi}^{K}{\\phi}_{K}0 describe two different forms of dark matter. The space-like ({\\phi}^{K}{\\phi}_{K}0) massive field displays repulsive elasticity. In balance with dark energy and ordinary matter it provides a four parametric diversity of regular solutions of the Einstein equations describing different possible cosmological and oscillating non-singular scenarios of evolution of the universe. In particular, the singular big bang turns into a regular inflation-like transition from contraction to expansion with the accelerate expansion at late times. The fine-tuned Friedman-Robertson-Walker singular solution is a particular limiting case at the boundary of existence of regular oscillating soluti...

  13. MACROSCOPIC DIVERSITY FOR CDMA MOBILE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Pei Xiaoyan; Hu Jiandong

    2002-01-01

    A novel system of macroscopic diversity with voting rule in CDMA cellular system is suggested in order to raise the coverage and quality of service of CDMA mobile communication system. The estimation of the impact of macroscopic diversity on performance of CDMA cellular system is analyzed and investigated.

  14. MACROSCOPIC DIVERSITY FOR CDMA MOBILE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    PeiXiaoyan; HuJiandong

    2002-01-01

    A novel system of macroscopic diversity with voting rule in CDMA cellular system is suggested in order to raise the coverage and quality of service of CDMA mobile communication system.The estimation of the impact of macroscopic diversity on performance of CDMA cellular system is analyzed and investigated.

  15. Macroscopic erosion of divertor and first wall armour in future tokamaks

    Science.gov (United States)

    Würz, H.; Bazylev, B.; Landman, I.; Pestchanyi, S.; Safronov, V.

    2002-12-01

    Sputtering, evaporation and macroscopic erosion determine the lifetime of the 'in vessel' armour materials CFC, tungsten and beryllium presently under discussion for future tokamaks. For CFC armour macroscopic erosion means brittle destruction and dust formation whereas for metallic armour melt layer erosion by melt motion and droplet splashing. Available results on macroscopic erosion from hot plasma and e-beam simulation experiments and from tokamaks are critically evaluated and a comprehensive discussion of experimental and numerical macroscopic erosion and its extrapolation to future tokamaks is given. Shielding of divertor armour materials by their own vapor exists during plasma disruptions. The evolving plasma shield protects the armour from high heat loads, absorbs the incoming energy and reradiates it volumetrically thus reducing drastically the deposited energy. As a result, vertical target erosion by vaporization turns out to be of the order of a few microns per disruption event and macroscopic erosion becomes the dominant erosion source.

  16. Meningioma: The role of a foreign body and irradiation in tumor formation

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, J.; Silberstein, H.J.; Salner, A.L.; Uphoff, D.F. (Hartford Hospital, CT (USA))

    1991-07-01

    A case of meningioma is reported. At the age of 18 years, the patient had undergone insertion of a Torkildsen shunt through a posteroparietal burr hole for obstructive hydrocephalus secondary to a tumor of the pineal region, of which no biopsy had been made. After the hydrocephalus was relieved, he underwent irradiation of the tumor. Thirty years later, he was treated for an intracranial meningioma wrapped around the shunt. The tumor followed the shunt in all of its intracranial course. Microscopy disclosed pieces of the shunt tube within the meningioma. The role of a foreign body and irradiation in the induction of meningiomas is discussed, and a comprehensive review of the literature is presented. 47 references.

  17. Rank distributions: A panoramic macroscopic outlook

    Science.gov (United States)

    Eliazar, Iddo I.; Cohen, Morrel H.

    2014-01-01

    This paper presents a panoramic macroscopic outlook of rank distributions. We establish a general framework for the analysis of rank distributions, which classifies them into five macroscopic "socioeconomic" states: monarchy, oligarchy-feudalism, criticality, socialism-capitalism, and communism. Oligarchy-feudalism is shown to be characterized by discrete macroscopic rank distributions, and socialism-capitalism is shown to be characterized by continuous macroscopic size distributions. Criticality is a transition state between oligarchy-feudalism and socialism-capitalism, which can manifest allometric scaling with multifractal spectra. Monarchy and communism are extreme forms of oligarchy-feudalism and socialism-capitalism, respectively, in which the intrinsic randomness vanishes. The general framework is applied to three different models of rank distributions—top-down, bottom-up, and global—and unveils each model's macroscopic universality and versatility. The global model yields a macroscopic classification of the generalized Zipf law, an omnipresent form of rank distributions observed across the sciences. An amalgamation of the three models establishes a universal rank-distribution explanation for the macroscopic emergence of a prevalent class of continuous size distributions, ones governed by unimodal densities with both Pareto and inverse-Pareto power-law tails.

  18. Macroscopic transport by synthetic molecular machines

    NARCIS (Netherlands)

    Berna, J; Leigh, DA; Lubomska, M; Mendoza, SM; Perez, EM; Rudolf, P; Teobaldi, G; Zerbetto, F

    2005-01-01

    Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with - and perform physical tasks in - the macroscopic world represents a significant hurdle

  19. Assessments of macroscopicity for quantum optical states

    DEFF Research Database (Denmark)

    Laghaout, Amine; Neergaard-Nielsen, Jonas Schou; Andersen, Ulrik Lund

    2015-01-01

    With the slow but constant progress in the coherent control of quantum systems, it is now possible to create large quantum superpositions. There has therefore been an increased interest in quantifying any claims of macroscopicity. We attempt here to motivate three criteria which we believe should...... enter in the assessment of macroscopic quantumness: The number of quantum fluctuation photons, the purity of the states, and the ease with which the branches making up the state can be distinguished. © 2014....

  20. Quantum Bell Inequalities from Macroscopic Locality

    CERN Document Server

    Yang, Tzyh Haur; Sheridan, Lana; Scarani, Valerio

    2010-01-01

    We propose a method to generate analytical quantum Bell inequalities based on the principle of Macroscopic Locality. By imposing locality over binary processings of virtual macroscopic intensities, we establish a correspondence between Bell inequalities and quantum Bell inequalities in bipartite scenarios with dichotomic observables. We discuss how to improve the latter approximation and how to extend our ideas to scenarios with more than two outcomes per setting.

  1. Regulation of Mammary Tumor Formation and Lipid Biosynthesis by Spot14

    Science.gov (United States)

    2014-06-01

    metabolism and altering the way they use the Citric Acid cycle in the mitochondria, tumor cells also increase de novo fatty acid synthesis. This is thought...SUPPLEMENTARY NOTES 14. ABSTRACT Spot14 (S14), encoded by the THRSP gene, regulates de novo fatty acid synthesis in the liver, adipose...and lactating mammary gland. S14 has recently been shown to stimulate FASN activity, increasing the synthesis of medium chain fatty acids in mammary

  2. Assessment of the role of circulating breast cancer cells in tumor formation and metastatic potential using in vivo flow cytometry

    Science.gov (United States)

    Hwu, Derrick; Boutrus, Steven; Greiner, Cherry; Dimeo, Theresa; Kuperwasser, Charlotte; Georgakoudi, Irene

    2011-04-01

    The identification of breast cancer patients who will ultimately progress to metastatic disease is of significant clinical importance. The quantification and assessment of circulating tumor cells (CTCs) has been proposed as one strategy to monitor treatment effectiveness and disease prognosis. However, CTCs have been an elusive population of cells to study because of their small number and difficulties associated with isolation protocols. In vivo flow cytometry (IVFC) can overcome these limitations and provide insights in the role these cells play during primary and metastatic tumor growth. In this study, we used two-color IVFC to examine, for up to ten weeks following orthotopic implantation, changes in the number of circulating human breast cells expressing GFP and a population of circulating hematopoietic cells with strong autofluorescence. We found that the number of detected CTCs in combination with the number of red autofluorescent cells (650 to 690 nm) during the first seven days following implantation was predictive in development of tumor formation and metastasis eight weeks later. These results suggest that the combined detection of these two cell populations could offer a novel approach in the monitoring and prognosis of breast cancer progression, which in turn could aid significantly in their effective treatment.

  3. Lupeol, a bioactive triterpene, prevents tumor formation during 7,12-dimethylbenz(a)anthracene induced oral carcinogenesis.

    Science.gov (United States)

    Palanimuthu, D; Baskaran, N; Silvan, S; Rajasekaran, D; Manoharan, S

    2012-10-01

    The oral cancer chemopreventive efficacy of lupeol, a bioactive triterpene, was assessed by monitoring the tumor incidence and using the status of phase I and II xenobiotic metabolizing enzymes, lipid peroxidation and antioxidants as biochemical end points during 7,12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogenesis. Oral tumors were developed in the buccal pouch of golden Syrian hamsters by painting with 0.5 % DMBA three times a week for 14 weeks. Well differentiated oral squamous cell carcinoma with marked abnormalities in the status of biochemical markers were noticed in hamsters treated with DMBA alone. Oral administration of lupeol at a dose of 50 mg/kg bw completely inhibited the formation of oral tumors and restored the status of biochemical markers during DMBA induced oral carcinogenesis. The present study thus demonstrates the chemopreventive potential of lupeol in DMBA induced oral carcinogenesis. The chemopreventive potential of lupeol is probably due to its antioxidant or free radical scavenging property and modulating effect on phase I and II xenobiotic metabolizing enzymes in favour of the excretion of carcinogenic metabolites during DMBA induced hamster buccal pouch carcinogenesis.

  4. Cisplatin-DNA adduct formation in patients treated with cisplatin-based chemoradiation: lack of correlation between normal tissues and primary tumor.

    NARCIS (Netherlands)

    Hoebers, F.J.; Pluim, D.; Hart, A.A.M.; Verheij, M.; Balm, A.J.M.; Fons, G.; Rasch, C.R.; Schellens, J.H.M.; Stalpers, L.J.A.; Bartelink, H.; Begg, A.C.

    2008-01-01

    PURPOSE: In this study, the formation of cisplatin-DNA adducts after concurrent cisplatin-radiation and the relationship between adduct-formation in primary tumor tissue and normal tissue were investigated. METHODS: Three intravenous cisplatin-regimens, given concurrently with radiation, were studie

  5. Cisplatin-DNA adduct formation in patients treated with cisplatin-based chemoradiation: lack of correlation between normal tissues and primary tumor

    NARCIS (Netherlands)

    Hoebers, F.J.P.; Pluim, D.; Hart, A.A.M.; Verheij, M.; Balm, A.J.M.; Fons, G.; Rasch, C.R.N.; Schellens, J.H.M.; Stalpers, L.J.A.; Bartelink, H.; Begg, A.C.

    2007-01-01

    Purpose: In this study, the formation of cisplatin-DNA adducts after concurrent cisplatin-radiation and the relationship between adduct-formation in primary tumor tissue and normal tissue were investigated. Methods: Three intravenous cisplatin-regimens, given concurrently with radiation, were stu

  6. Somatic mutagenesis with a Sleeping Beauty transposon system leads to solid tumor formation in zebrafish.

    Directory of Open Access Journals (Sweden)

    Maura McGrail

    Full Text Available Large-scale sequencing of human cancer genomes and mouse transposon-induced tumors has identified a vast number of genes mutated in different cancers. One of the outstanding challenges in this field is to determine which genes, when mutated, contribute to cellular transformation and tumor progression. To identify new and conserved genes that drive tumorigenesis we have developed a novel cancer model in a distantly related vertebrate species, the zebrafish, Danio rerio. The Sleeping Beauty (SB T2/Onc transposon system was adapted for somatic mutagenesis in zebrafish. The carp ß-actin promoter was cloned into T2/Onc to create T2/OncZ. Two transgenic zebrafish lines that contain large concatemers of T2/OncZ were isolated by injection of linear DNA into the zebrafish embryo. The T2/OncZ transposons were mobilized throughout the zebrafish genome from the transgene array by injecting SB11 transposase RNA at the 1-cell stage. Alternatively, the T2/OncZ zebrafish were crossed to a transgenic line that constitutively expresses SB11 transposase. T2/OncZ transposon integration sites were cloned by ligation-mediated PCR and sequenced on a Genome Analyzer II. Between 700-6800 unique integration events in individual fish were mapped to the zebrafish genome. The data show that introduction of transposase by transgene expression or RNA injection results in an even distribution of transposon re-integration events across the zebrafish genome. SB11 mRNA injection resulted in neoplasms in 10% of adult fish at ∼10 months of age. T2/OncZ-induced zebrafish tumors contain many mutated genes in common with human and mouse cancer genes. These analyses validate our mutagenesis approach and provide additional support for the involvement of these genes in human cancers. The zebrafish T2/OncZ cancer model will be useful for identifying novel and conserved genetic drivers of human cancers.

  7. Reciprocal Interactions between Multiple Myeloma Cells and Osteoprogenitor Cells Affect Bone Formation and Tumor Growth

    Science.gov (United States)

    2015-12-01

    says Kornelia Polyak , MD, PhD, a breast cancer geneti- cist at DF/BWCC. Breast cancer cells are sur- rounded by a “stroma” composed mostly of...tant to treatment,” says Polyak . In one line of microenviron- ment research, Polyak’s lab is focusing on the role of fibroblasts “The whole idea...Kornelia Polyak MD, PhD (lower right), each explore different aspects of the tumor microenvironment – the molecules, cells, and blood vessels that

  8. Autophagy is involved in TGF-β1-induced protective mechanisms and formation of cancer-associated fibroblasts phenotype in tumor microenvironment.

    Science.gov (United States)

    Liu, Fang-Lan; Mo, En-Pan; Yang, Liu; Du, Jun; Wang, Hong-Sheng; Zhang, Huan; Kurihara, Hiroshi; Xu, Jun; Cai, Shao-Hui

    2016-01-26

    Transforming growth factor-β1 (TGF-β1) present in tumor microenvironment acts in a coordinated fashion to either suppress or promote tumor development. However, the molecular mechanisms underlying the effects of TGF-β1 on tumor microenvironment are not well understood. Our clinical data showed a positive association between TGF-β1 expression and cancer-associated fibroblasts (CAFs) in tumor microenvironment of breast cancer patients. Thus we employed starved NIH3T3 fibroblasts in vitro and 4T1 cells mixed with NIH3T3 fibroblasts xenograft model in vivo to simulate nutritional deprivation of tumor microenvironment to explore the effects of TGF-β1. We demonstrated that TGF-β1 protected NIH3T3 fibroblasts from Star-induced growth inhibition, mitochondrial damage and cell apoptosis. Interestingly, TGF-β1 induced the formation of CAFs phenotype in starvation (Star)-treated NIH3T3 fibroblasts and xenografted Balb/c mice, which promoted breast cancer tumor growth. In both models, autophagy agonist rapamycin increased TGF-β1-induced protective effects and formation of CAFs phenotypes, while autophagy inhibitor 3-methyladenine, Atg5 knockdown or TGF-β type I receptor kinase inhibitor LY-2157299 blocked TGF-β1 induced these effects. Taken together, our results indicated that TGF-β/Smad autophagy was involved in TGF-β1-induced protective effects and formation of CAFs phenotype in tumor microenvironment, which may be used as therapy targets in breast cancer.

  9. Loss of Serglycin Promotes Primary Tumor Growth and Vessel Functionality in the RIP1-Tag2 Mouse Model for Spontaneous Insulinoma Formation.

    Directory of Open Access Journals (Sweden)

    Andrew Hamilton

    Full Text Available The serglycin proteoglycan is mainly expressed by hematopoietic cells where the major function is to retain the content of storage granules and vesicles. In recent years, expression of serglycin has also been found in different forms of human malignancies and a high serglycin expression level has been correlated with a more migratory and invasive phenotype in the case of breast cancer and nasopharyngeal carcinoma. Serglycin has also been implicated in the development of the tumor vasculature in multiple myeloma and hepatocellular carcinoma where reduced expression of serglycin was correlated with a less extensive vasculature. To further investigate the contribution of serglycin to tumor development, we have used the immunocompetent RIP1-Tag2 mouse model of spontaneous insulinoma formation crossed into serglycin deficient mice. For the first time we show that serglycin-deficiency affects orthotopic primary tumor growth and tumor vascular functionality of late stage carcinomas. RIP1-Tag2 mice that lack serglycin develop larger tumors with a higher proliferative activity but unaltered apoptosis compared to normal RIP1-Tag2 mice. The absence of serglycin also enhances the tumor vessel functionality, which is better perfused than in tumors from serglycin wild type mice. The presence of the pro-angiogenic modulators vascular endothelial growth factor and hepatocyte growth factor were decreased in the serglycin deficient mice which suggests a less pro-angiogenic environment in the tumors of these animals. Taken together, we conclude that serglycin affects multiple aspects of spontaneous tumor formation, which strengthens the theory that serglycin acts as an important mediator in the formation and progression of tumors.

  10. Formation of Ion-Permeable Channels by Tumor Necrosis Factor-α

    Science.gov (United States)

    Kagan, Bruce L.; Baldwin, Rae Lynn; Munoz, David; Wisnieski, Bernadine J.

    1992-03-01

    Tumor necrosis factor-α (TNF, cachectin), a protein secreted by activated macrophages, participates in inflammatory responses and in infectious and neoplastic disease states. The mechanisms by which TNF exerts cytotoxic, hormonal, and other specific effects are obscure. Structural studies of the TNF trimer have revealed a central pore-like region. Although several amino acid side chains appear to preclude an open channel, the ability of TNF to insert into lipid vesicles raised the possibility that opening might occur in a bilayer milieu. Acidification of TNF promoted conformational changes concordant with increased surface hydrophobicity and membrane insertion. Furthermore, TNF formed pH-dependent, voltage-dependent, ion-permeable channels in planar lipid bilayer membranes and increased the sodium permeability of human U937 histiocytic lymphoma cells. Thus, some of the physiological effects of TNF may be elicited through its intrinsic ion channel-forming activity.

  11. Self-Feeding Turbulent Magnetic Reconnection on Macroscopic Scales

    CERN Document Server

    Lapenta, Giovanni

    2008-01-01

    Within a MHD approach we find magnetic reconnection to progress in two entirely different ways. The first is well-known: the laminar Sweet-Parker process. But a second, completely different and chaotic reconnection process is possible. This regime has properties of immediate practical relevance: i) it is much faster, developing on scales of the order of the Alfv\\'en time, and ii) the areas of reconnection become distributed chaotically over a macroscopic region. The onset of the faster process is the formation of closed circulation patterns where the jets going out of the reconnection regions turn around and forces their way back in, carrying along copious amounts of magnetic flux.

  12. Macroscopic optical response and photonic bands

    CERN Document Server

    Perez-Huerta, J S; Mendoza, Bernardo S; Mochan, W Luis

    2012-01-01

    We develop a formalism for the calculation of the macroscopic dielectric response of composite systems made of particles of one material embedded periodically within a matrix of another material, each of which is characterized by a well defined dielectric function. The nature of these dielectric functions is arbitrary, and could correspond to dielectric or conducting, transparent or opaque, absorptive and dispersive materials. The geometry of the particles and the Bravais lattice of the composite are also arbitrary. Our formalism goes beyond the longwavelenght approximation as it fully incorporates retardation effects. We test our formalism through the study the propagation of electromagnetic waves in 2D photonic crystals made of periodic arrays of cylindrical holes in a dispersionless dielectric host. Our macroscopic theory yields a spatially dispersive macroscopic response which allows the calculation of the full photonic band structure of the system, as well as the characterization of its normal modes, upo...

  13. A macroscopic challenge for quantum spacetime

    CERN Document Server

    Amelino-Camelia, Giovanni

    2013-01-01

    Over the last decade a growing number of quantum-gravity researchers has been looking for opportunities for the first ever experimental evidence of a Planck-length quantum property of spacetime. These studies are usually based on the analysis of some candidate indirect implications of spacetime quantization, such as a possible curvature of momentum space. Some recent proposals have raised hope that we might also gain direct experimental access to quantum properties of spacetime, by finding evidence of limitations to the measurability of the center-of-mass coordinates of some macroscopic bodies. However I here observe that the arguments that originally lead to speculating about spacetime quantization do not apply to the localization of the center of mass of a macroscopic body. And I also analyze some popular formalizations of the notion of quantum spacetime, finding that when the quantization of spacetime is Planckian for the constituent particles then for the composite macroscopic body the quantization of spa...

  14. On Macroscopic Complexity and Perceptual Coding

    CERN Document Server

    Scoville, John

    2010-01-01

    While Shannon information establishes limits to the universal data compression of binary data, no existing theory provides an equivalent characterization of the lossy data compression algorithms prevalent in audiovisual media. The current paper proposes a mathematical framework for perceptual coding and inference which quantifies the complexity of objects indistinguishable to a particular observer. A definition of the complexity is presented and related to a generalization of Boltzmann entropy for these equivalence classes. When the classes are partitions of phase space, corresponding to classical observations, this is the proper Boltzmann entropy and the macroscopic complexity agrees with the Algorithmic Entropy. For general classes, the macroscopic complexity measure determines the optimal lossy compression of the data. Conversely, perceptual coding algorithms may be used to construct upper bounds on certain macroscopic complexities. Knowledge of these complexities, in turn, allows perceptual inference whic...

  15. Nanoplasmon-enabled macroscopic thermal management

    CERN Document Server

    Jonsson, Gustav Edman; Dmitriev, Alexandre

    2013-01-01

    In numerous applications of energy harvesting via transformation of light into heat the focus recently shifted towards highly absorptive materials featuring nanoplasmons. It is currently established that noble metals-based absorptive plasmonic platforms deliver significant light-capturing capability and can be viewed as super-absorbers of optical radiation. However, direct experimental evidence of plasmon-enabled macroscopic temperature increase that would result from these efficient absorptive properties is scarce. Here we derive a general quantitative method of characterizing light-capturing properties of a given heat-generating absorptive layer by macroscopic thermal imaging. We further monitor macroscopic areas that are homogeneously heated by several degrees with plasmon nanostructures that occupy a mere 8% of the surface, leaving it essentially transparent and evidencing significant heat generation capability of nanoplasmon-enabled light capture. This has a direct bearing to thermophotovoltaics and othe...

  16. Tumor promoters cause a rapid and reversible inhibition of the formation and maintenance of electrical cell coupling in culture.

    Science.gov (United States)

    Enomoto, T; Sasaki, Y; Shiba, Y; Kanno, Y; Yamasaki, H

    1981-01-01

    The effect of tumor promoters on electrical coupling between human FL cells was investigated with a microelectrode technique. When a low concentration (100 ng/ml) of 12-O-tetradecanoylphorbol 13-acetate (TPA) was added to culture medium, only 6% of the cells showed electrical coupling after 5 hr, whereas in control medium more than 90% of the cells were coupled. In the presence of TPA, cell coupling remained suppressed for at least another 19 hr. When TPA was washed out from the culture medium, the cells commenced electrical coupling: 90% of the cells were coupled within 4 hr of the removal of TPA, a rate very similar to that of nontreated control cells. Therefore, TPA-mediated inhibition of cell coupling is reversible. When TPA was added to a culture in which more than 90% of the cells had already established electrical coupling, the percentage of coupled cells decreased to 6% within 8 hr, indicating that TPA can also diminish already established cell coupling. Inhibition of cell coupling also was achieved with other mouse skin tumor promoters--phorbol 12,13-didecanoate, ingenol dibenzoate, and mezerein--whereas nonpromoting derivatives--phorbol and 4 alpha-phorbol 12,13-didecanoate-showed no effect. None of these compounds changed the membrane potential, membrane resistance, or growth rate of FL cells. Thus, it appears that TPA and structurally-related tumor promoters specifically disturb the formation or function, or both, of cell-cell junctions, without significantly affecting the general properties of the surface membrane or the growth of FL cells. Images PMID:6946500

  17. Ground testing of bioconvective variables such as morphological characterizations and mechanisms which regulate macroscopic patterns

    Science.gov (United States)

    Johnson, Adriel D.

    1992-01-01

    Conditions simulating low- and high-gravity, reveal changes in macroscopic pattern formation in selected microorganisms, but whether these structures are gravity dependent is not clear. Two theories have been identified in the fluid dynamics community which support macroscopic pattern formation. The first one is gravity dependent (fluid density models) where small concentrated regions of organisms sink unstably, and the second is gravity independent (wave reinforcement theory) where organisms align their movements in concert, such that either their swimming strokes beat in phase or their vortices entrain neighbors to follow parallel paths. Studies have shown that macroscopic pattern formation is consistent with the fluid density models for protozoa and algae and wave reinforcement hypothesis for caprine spermatozoa.

  18. Effect of low-energy laser irradiation on colony formation capability in different human tumor cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Marchesini, R.; Dasdia, T.; Melloni, E.; Rocca, E.

    1989-01-01

    Fibroblasts and lymphocytes are the most widely used cells for studying the so-called biostimulative effect of low-power laser in vitro. In contrast, stimulation of cancer cells by laser light has not been investigated extensively. The present study attempted to evaluate whether or not human tumor cells could exhibit an increase in colony-forming capability following low-watt laser irradiation. LoVo and HT29 (colon carcinoma), MCF7 (breast carcinoma), M14 and JR1 (malignant melanoma) cell lines were irradiated at different doses of light delivered from an argon or an argon-dye laser. Radiant exposures between 4.2 and 150 kJ/m2 at irradiances ranging from 35 to 500 W/m2 were delivered. Results were mixed. Of the 41 experiments performed, five showed a significant statistical increase in the number of colonies (P less than 0.05), whereas three showed a decrease (P less than 0.05). Nevertheless, the trend of most data was toward an increase in colony formation, and Wilcoxon's signed-ranks test suggested that light increases tumor cell culture growth (P less than 0.03).

  19. Circular RNA alterations are involved in resistance to avian leukosis virus subgroup-J-induced tumor formation in chickens.

    Science.gov (United States)

    Zhang, Xinheng; Yan, Yiming; Lei, Xiaoya; Li, Aijun; Zhang, Huanmin; Dai, Zhenkai; Li, Xinjian; Chen, Weiguo; Lin, Wencheng; Chen, Feng; Ma, Jingyun; Xie, Qingmei

    2017-05-23

    Avian leukosis virus subgroup (ALV-J) is an oncogenic neoplasm-inducing retrovirus that causes significant economic losses in the poultry industry. Recent studies have demonstrated circular RNAs (circRNAs) are implicated in pathogenic processes; however, no research has indicated circRNAs are involved in resistance to disease. In this study, over 1800 circRNAs were detected by circRNA sequencing of liver tissues from ALV-J-resistant (n = 3) and ALV-J-susceptible chickens (n = 3). 32 differentially expressed circRNAs were selected for analyzing including 12 upregulated in ALV-J-resistant chickens and 20 upregulated in ALV-J-susceptible chickens, besides, the top five microRNAs (miRNAs) for 12 upregulated circRNAs in ALV-J-resistant chickens were analyzed. Gene ontology and KEGG pathway analyses were performed for miRNA target genes, the predicted genes were mainly involved in immune pathways. This study provides the first evidence that circRNA alterations are involved in resistance to ALV-J-induced tumor formation. We propose circRNAs may help to mediate tumor induction and development in chickens.

  20. Carbohydrate malabsorption mechanism for tumor formation in rats treated with the SGLT2 inhibitor canagliflozin.

    Science.gov (United States)

    Mamidi, Rao N V S; Proctor, Jim; De Jonghe, Sandra; Feyen, Bianca; Moesen, Esther; Vinken, Petra; Ma, Jing Ying; Bryant, Stewart; Snook, Sandra; Louden, Calvert; Lammens, Godelieve; Ways, Kirk; Kelley, Michael F; Johnson, Mark D

    2014-09-25

    Canagliflozin is an SGLT2 inhibitor used for the treatment of type 2 diabetes mellitus. Studies were conducted to investigate the mechanism responsible for renal tubular tumors and pheochromocytomas observed at the high dose in a 2-year carcinogenicity study in rats. At the high dose (100mg/kg) in rats, canagliflozin caused carbohydrate malabsorption evidenced by inhibition of intestinal glucose uptake, decreased intestinal pH and increased urinary calcium excretion. In a 6-month mechanistic study utilization of a glucose-free diet prevented carbohydrate malabsorption and its sequelae, including increased calcium absorption and urinary calcium excretion, and hyperostosis. Cell proliferation in the kidney and adrenal medulla was increased in rats maintained on standard diet and administered canagliflozin (100mg/kg), and in addition an increase in the renal injury biomarker KIM-1 was observed. Increased cell proliferation is considered as a proximal event in carcinogenesis. Effects on cell proliferation, KIM-1 and calcium excretion were inhibited in rats maintained on the glucose-free diet, indicating they are secondary to carbohydrate malabsorption and are not direct effects of canagliflozin. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Prevalence of heterotypic tumor/immune cell-in-cell structure in vitro and in vivo leading to formation of aneuploidy.

    Directory of Open Access Journals (Sweden)

    Yu-hui Chen

    Full Text Available Cell-in-cell structures refer to a unique phenomenon that one living cell enters into another living cell intactly, occurring between homotypic tumor cells or tumor (or other tissue cells and immune cells (named as heterotypic cell-in-cell structure. In the present study, through a large scale of survey we observed that heterotypic cell-in-cell structure formation occurred commonly in vitro with host cells derived from different human carcinomas as well as xenotypic mouse tumor cell lines. Most of the lineages of human immune cells, including T, B, NK cells, monocytes as well as in vitro activated LAK cells, were able to invade tumor cell lines. Poorly differentiated stem cells were capable of internalizing immune cells as well. More significantly, heterotypic tumor/immune cell-in-cell structures were observed in a higher frequency in tumor-derived tissues than those in adjacent tissues. In mouse hepatitis models, heterotypic immune cell/hepatocyte cell-in-cell structures were also formed in a higher frequency than in normal controls. After in vitro culture, different forms of internalized immune cells in heterotypic cell-in-cell structures were observed, with one or multiple immune cells inside host cells undergoing resting, degradation or mitosis. More strikingly, some internalized immune cells penetrated directly into the nucleus of target cells. Multinuclear cells with aneuploid nucleus were formed in target tumor cells after internalizing immune cells as well as in situ tumor regions. Therefore, with the prevalence of heterotypic cell-in-cell structures observed, we suggest that shielding of immune cells inside tumor or inflammatory tissue cells implies the formation of aneuploidy with the increased multinucleation as well as fine-tuning of microenvironment under pathological status, which may define distinct mechanisms to influence the etiology and progress of tumors.

  2. Separation of the Microscopic and Macroscopic Domains

    Science.gov (United States)

    Van Zandt, L. L.

    1977-01-01

    Examines the possibility of observing interference in quantum magnification experiments such as the celebrated "Schroedinger cat". Uses the possibility of observing interference for separating the realm of microscopic from macroscopic dynamics; estimates the dividing line to fall at system sizes of about 100 Daltons. (MLH)

  3. Entropy, Macroscopic Information, and Phase Transitions

    OpenAIRE

    Parrondo, Juan M. R.

    1999-01-01

    The relationship between entropy and information is reviewed, taking into account that information is stored in macroscopic degrees of freedom, such as the order parameter in a system exhibiting spontaneous symmetry breaking. It is shown that most problems of the relationship between entropy and information, embodied in a variety of Maxwell demons, are also present in any symmetry breaking transition.

  4. Macroscopic Modeling of Polymer-Electrolyte Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Weber, A.Z.; Newman, J.

    2007-04-01

    In this chapter, the various approaches for the macroscopic modeling of transport phenomena in polymer-electrolyte membranes are discussed. This includes general background and modeling methodologies, as well as exploration of the governing equations and some membrane-related topic of interest.

  5. Lozenge Tilings, Glauber Dynamics and Macroscopic Shape

    Science.gov (United States)

    Laslier, Benoît; Toninelli, Fabio Lucio

    2015-09-01

    We study the Glauber dynamics on the set of tilings of a finite domain of the plane with lozenges of side 1/ L. Under the invariant measure of the process (the uniform measure over all tilings), it is well known (Cohn et al. J Am Math Soc 14:297-346, 2001) that the random height function associated to the tiling converges in probability, in the scaling limit , to a non-trivial macroscopic shape minimizing a certain surface tension functional. According to the boundary conditions, the macroscopic shape can be either analytic or contain "frozen regions" (Arctic Circle phenomenon Cohn et al. N Y J Math 4:137-165, 1998; Jockusch et al. Random domino tilings and the arctic circle theorem, arXiv:math/9801068, 1998). It is widely conjectured, on the basis of theoretical considerations (Henley J Statist Phys 89:483-507, 1997; Spohn J Stat Phys 71:1081-1132, 1993), partial mathematical results (Caputo et al. Commun Math Phys 311:157-189, 2012; Wilson Ann Appl Probab 14:274-325, 2004) and numerical simulations for similar models (Destainville Phys Rev Lett 88:030601, 2002; cf. also the bibliography in Henley (J Statist Phys 89:483-507, 1997) and Wilson (Ann Appl Probab 14:274-325, 2004), that the Glauber dynamics approaches the equilibrium macroscopic shape in a time of order L 2+ o(1). In this work we prove this conjecture, under the assumption that the macroscopic equilibrium shape contains no "frozen region".

  6. Macroscopic invisibility cloaking of visible light

    DEFF Research Database (Denmark)

    Chen, Xianzhong; Luo, Y.; Zhang, Jingjing

    2011-01-01

    to a few wavelengths. Here, we report the first realization of a macroscopic volumetric invisibility cloak constructed from natural birefringent crystals. The cloak operates at visible frequencies and is capable of hiding, for a specific light polarization, three-dimensional objects of the scale...

  7. A macroscopic model of traffic jams in axons.

    Science.gov (United States)

    Kuznetsov, A V; Avramenko, A A

    2009-04-01

    The purpose of this paper is to develop a minimal macroscopic model capable of explaining the formation of traffic jams in fast axonal transport. The model accounts for the decrease of the number density of positively (and negatively) oriented microtubules near the location of the traffic jam due to formation of microtubule swirls; the model also accounts for the reduction of the effective velocity of organelle transport in the traffic jam region due to organelles falling off microtubule tracks more often in the swirl region. The model is based on molecular-motor-assisted transport equations and the hydrodynamic model of traffic jams in highway traffic. Parametric analyses of the model's predictions for various values of viscosity of the traffic flow, variance of the velocity distribution, diffusivity of microtubule-bound and free organelles, rate constants for binding to and detachment from microtubules, relaxation time, and average motor velocities of the retrograde and anterograde transport, are carried out.

  8. FGF2 and EGF Are Required for Self-Renewal and Organoid Formation of Canine Normal and Tumor Breast Stem Cells.

    Science.gov (United States)

    Cocola, Cinzia; Molgora, Stefano; Piscitelli, Eleonora; Veronesi, Maria Cristina; Greco, Marianna; Bragato, Cinzia; Moro, Monica; Crosti, Mariacristina; Gray, Brian; Milanesi, Luciano; Grieco, Valeria; Luvoni, Gaia Cecilia; Kehler, James; Bellipanni, Gianfranco; Reinbold, Rolland; Zucchi, Ileana; Giordano, Antonio

    2017-03-01

    Recent studies suggest that human tumors are generated from cancer cells with stem cell (SC) properties. Spontaneously occurring cancers in dogs contain a diversity of cells that like for human tumors suggest that certain canine tumors are also generated from cancer stem cells (CSCs). CSCs, like normal SCs, have the capacity for self-renewal as mammospheres in suspension cultures. To understand how cells with SC properties contribute to canine mammary gland tumor development and progression, comparative analysis between normal SCs and CSCs, obtained from the same individual, is essential. We have utilized the property of sphere formation to develop culture conditions for propagating stem/progenitor cells from canine normal and tumor tissue. We show that cells from dissociated mammospheres retain sphere reformation capacity for several serial passages and have the capacity to generate organoid structures ex situ. Utilizing various culture conditions for passaging SCs and CSCs, fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF) were found to positively or negatively regulate mammosphere regeneration, organoid formation, and multi-lineage differentiation potential. The response of FGF2 and EGF on SCs and CSCs was different, with increased FGF2 and EGF self-renewal promoted in SCs and repressed in CSCs. Our protocol for propagating SCs from normal and tumor canine breast tissue will provide new opportunities in comparative mammary gland stem cell analysis between species and anticancer treatment and therapies for dogs. J. Cell. Biochem. 118: 570-584, 2017. © 2016 Wiley Periodicals, Inc.

  9. Herpesviral G protein-coupled receptors activate NFAT to induce tumor formation via inhibiting the SERCA calcium ATPase.

    Directory of Open Access Journals (Sweden)

    Junjie Zhang

    2015-03-01

    Full Text Available G protein-coupled receptors (GPCRs constitute the largest family of proteins that transmit signal to regulate an array of fundamental biological processes. Viruses deploy diverse tactics to hijack and harness intracellular signaling events induced by GPCR. Herpesviruses encode multiple GPCR homologues that are implicated in viral pathogenesis. Cellular GPCRs are primarily regulated by their cognate ligands, while herpesviral GPCRs constitutively activate downstream signaling cascades, including the nuclear factor of activated T cells (NFAT pathway. However, the roles of NFAT activation and mechanism thereof in viral GPCR tumorigenesis remain unknown. Here we report that GPCRs of human Kaposi's sarcoma-associated herpesvirus (kGPCR and cytomegalovirus (US28 shortcut NFAT activation by inhibiting the sarcoplasmic reticulum calcium ATPase (SERCA, which is necessary for viral GPCR tumorigenesis. Biochemical approaches, entailing pharmacological inhibitors and protein purification, demonstrate that viral GPCRs target SERCA2 to increase cytosolic calcium concentration. As such, NFAT activation induced by vGPCRs was exceedingly sensitive to cyclosporine A that targets calcineurin, but resistant to inhibition upstream of ER calcium release. Gene expression profiling identified a signature of NFAT activation in endothelial cells expressing viral GPCRs. The expression of NFAT-dependent genes was up-regulated in tumors derived from tva-kGPCR mouse and human KS. Employing recombinant kGPCR-deficient KSHV, we showed that kGPCR was critical for NFAT-dependent gene expression in KSHV lytic replication. Finally, cyclosporine A treatment diminished NFAT-dependent gene expression and tumor formation induced by viral GPCRs. These findings reveal essential roles of NFAT activation in viral GPCR tumorigenesis and a mechanism of "constitutive" NFAT activation by viral GPCRs.

  10. Macroscopic quantum mechanics in a classical spacetime.

    Science.gov (United States)

    Yang, Huan; Miao, Haixing; Lee, Da-Shin; Helou, Bassam; Chen, Yanbei

    2013-04-26

    We apply the many-particle Schrödinger-Newton equation, which describes the coevolution of a many-particle quantum wave function and a classical space-time geometry, to macroscopic mechanical objects. By averaging over motions of the objects' internal degrees of freedom, we obtain an effective Schrödinger-Newton equation for their centers of mass, which can be monitored and manipulated at quantum levels by state-of-the-art optomechanics experiments. For a single macroscopic object moving quantum mechanically within a harmonic potential well, its quantum uncertainty is found to evolve at a frequency different from its classical eigenfrequency-with a difference that depends on the internal structure of the object-and can be observable using current technology. For several objects, the Schrödinger-Newton equation predicts semiclassical motions just like Newtonian physics, yet quantum uncertainty cannot be transferred from one object to another.

  11. Macroscopic Invisibility Cloaking of Visible Light

    CERN Document Server

    Chen, Xianzhong; Zhang, Jingjing; Jiang, Kyle; Pendry, John B; Zhang, Shuang

    2010-01-01

    Invisibility cloaks of light, which used to be confined to the imagination, have now been turned into a scientific reality, thanks to the enabling theoretical tools of transformation optics and conformal mapping. Inspired by those theoretical works, the experimental realisation of electromagnetic invisibility cloaks has been reported at various electromagnetic frequencies. All the invisibility cloaks demonstrated thus far, however, have relied on nano- or micro-fabricated artificial composite materials with spatially varying electromagnetic properties, which limit the size of the cloaked region to a few wavelengths. Here we report realisation of a macroscopic volumetric invisibility cloak constructed from natural birefringent crystals. The cloak operates at visible frequencies and is capable of hiding three-dimensional objects of the scale of centimetres and millimetres. Our work opens avenues for future applications with macroscopic cloaking devices.

  12. Macroscopic spin and charge transport theory

    Institute of Scientific and Technical Information of China (English)

    Li Da-Fang; Shi Jun-Ren

    2009-01-01

    According to the general principle of non-equilibrium thermodynamics, we propose a set of macroscopic transport equations for the spin transport and the charge transport. In particular, the spin torque is introduced as a generalized 'current density' to describe the phenomena associated with the spin non-conservation in a unified framework. The Einstein relations and the Onsager relations between different transport phenomena are established. Specifically, the spin transport properties of the isotropic non-magnetic and the isotropic magnetic two-dimensional electron gases are fully described by using this theory, in which only the macroscopic-spin-related transport phenomena allowed by the symmetry of the system are taken into account.

  13. Macroscopic entrainment of periodically forced oscillatory ensembles.

    Science.gov (United States)

    Popovych, Oleksandr V; Tass, Peter A

    2011-03-01

    Large-amplitude oscillations of macroscopic neuronal signals, such as local field potentials and electroencephalography or magnetoencephalography signals, are commonly considered as being generated by a population of mutually synchronized neurons. In a computational study in generic networks of phase oscillators and bursting neurons, however, we show that this common belief may be wrong if the neuronal population receives an external rhythmic input. The latter may stem from another neuronal population or an external, e.g., sensory or electrical, source. In that case the population field potential may be entrained by the rhythmic input, whereas the individual neurons are phase desynchronized both mutually and with their field potential. Intriguingly, the corresponding large-amplitude oscillations of the population mean field are generated by pairwise desynchronized neurons oscillating at frequencies shifted far away from the frequency of the macroscopic field potential.

  14. Adsorption modeling for macroscopic contaminant dispersal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Axley, J.W.

    1990-05-01

    Two families of macroscopic adsorption models are formulated, based on fundamental principles of adsorption science and technology, that may be used for macroscopic (such as whole-building) contaminant dispersal analysis. The first family of adsorption models - the Equilibrium Adsorption (EA) Models - are based upon the simple requirement of equilibrium between adsorbent and room air. The second family - the Boundary Layer Diffusion Controlled Adsorption (BLDC) Models - add to the equilibrium requirement a boundary layer model for diffusion of the adsorbate from the room air to the adsorbent surface. Two members of each of these families are explicitly discussed, one based on the linear adsorption isotherm model and the other on the Langmuir model. The linear variants of each family are applied to model the adsorption dynamics of formaldehyde in gypsum wall board and compared to measured data.

  15. Macroscopic Invisible Cloak for Visible Light

    CERN Document Server

    Zhang, Baile; Liu, Xiaogang; Barbastathis, George

    2011-01-01

    Invisibility cloaks, a subject that usually occurs in science fiction and myths, have attracted wide interest recently because of their possible realization. The biggest challenge to true invisibility is known to be the cloaking of a macroscopic object in the broad range of wavelengths visible to the human eye. Here we experimentally solve this problem by incorporating the principle of transformation optics into a conventional optical lens fabrication with low-cost materials and simple manufacturing techniques. A transparent cloak made of two pieces of calcite is created. This cloak is able to conceal a macroscopic object with a maximum height of 2 mm, larger than 3500 free-space-wavelength, inside a transparent liquid environment. Its working bandwidth encompassing red, green and blue light is also demonstrated.

  16. Macroscopic Quantum Resonators (MAQRO): 2015 update

    Energy Technology Data Exchange (ETDEWEB)

    Kaltenbaek, Rainer [University of Vienna, Vienna Center for Quantum Science and Technology, Vienna (Austria); Aspelmeyer, Markus; Kiesel, Nikolai [University of Vienna, Vienna Center for Quantum Science and Technology, Vienna (Austria); Barker, Peter F.; Bose, Sougato [University College London, Department of Physics and Astronomy, London (United Kingdom); Bassi, Angelo [University of Trieste, Department of Physics, Trieste (Italy); INFN - Trieste Section, Trieste (Italy); Bateman, James [University of Swansea, Department of Physics, College of Science, Swansea (United Kingdom); Bongs, Kai; Cruise, Adrian Michael [University of Birmingham, School of Physics and Astronomy, Birmingham (United Kingdom); Braxmaier, Claus [University of Bremen, Center of Applied Space Technology and Micro Gravity (ZARM), Bremen (Germany); Institute of Space Systems, German Aerospace Center (DLR), Bremen (Germany); Brukner, Caslav [University of Vienna, Vienna Center for Quantum Science and Technology, Vienna (Austria); Austrian Academy of Sciences, Institute of Quantum Optics and Quantum Information (IQOQI), Vienna (Austria); Christophe, Bruno; Rodrigues, Manuel [The French Aerospace Lab, ONERA, Chatillon (France); Chwalla, Michael; Johann, Ulrich [Airbus Defence and Space GmbH, Immenstaad (Germany); Cohadon, Pierre-Francois; Heidmann, Antoine; Lambrecht, Astrid; Reynaud, Serge [ENS-PSL Research University, Laboratoire Kastler Brossel, UPMC-Sorbonne Universites, CNRS, College de France, Paris (France); Curceanu, Catalina [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Dholakia, Kishan; Mazilu, Michael [University of St. Andrews, School of Physics and Astronomy, St. Andrews (United Kingdom); Diosi, Lajos [Wigner Research Center for Physics, P.O. Box 49, Budapest (Hungary); Doeringshoff, Klaus; Peters, Achim [Humboldt-Universitaet zu Berlin, Institut fuer Physik, Berlin (Germany); Ertmer, Wolfgang; Rasel, Ernst M. [Leibniz Universitaet Hannover, Institut fuer Quantenoptik, Hannover (Germany); Gieseler, Jan; Novotny, Lukas; Rondin, Loic [ETH Zuerich, Photonics Laboratory, Zuerich (Switzerland); Guerlebeck, Norman; Herrmann, Sven; Laemmerzahl, Claus [University of Bremen, Center of Applied Space Technology and Micro Gravity (ZARM), Bremen (Germany); Hechenblaikner, Gerald [Airbus Defence and Space GmbH, Immenstaad (Germany); European Southern Observatory (ESO), Garching bei Muenchen (Germany); Hossenfelder, Sabine [KTH Royal Institute of Technology and Stockholm University, Nordita, Stockholm (Sweden); Kim, Myungshik [Imperial College London, QOLS, Blackett Laboratory, London (United Kingdom); Milburn, Gerard J. [University of Queensland, ARC Centre for Engineered Quantum Systems, Brisbane (Australia); Mueller, Holger [University of California, Department of Physics, Berkeley, CA (United States); Paternostro, Mauro [Queen' s University, Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Belfast (United Kingdom); Pikovski, Igor [Harvard-Smithsonian Center for Astrophysics, ITAMP, Cambridge, MA (United States); Pilan Zanoni, Andre [Airbus Defence and Space GmbH, Immenstaad (Germany); CERN - European Organization for Nuclear Research, EN-STI-TCD, Geneva (Switzerland); Riedel, Charles Jess [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada); Roura, Albert [Universitaet Ulm, Institut fuer Quantenphysik, Ulm (Germany); Schleich, Wolfgang P. [Universitaet Ulm, Institut fuer Quantenphysik, Ulm (Germany); Texas A and M University Institute for Advanced Study (TIAS), Institute for Quantum Science and Engineering (IQSE), and Department of Physics and Astronomy, College Station, TX (United States); Schmiedmayer, Joerg [Vienna University of Technology, Vienna Center for Quantum Science and Technology, Institute of Atomic and Subatomic Physics, Vienna (Austria); Schuldt, Thilo [Institute of Space Systems, German Aerospace Center (DLR), Bremen (Germany); Schwab, Keith C. [California Institute of Technology, Applied Physics, Pasadena, CA (United States)

    2016-12-15

    Do the laws of quantum physics still hold for macroscopic objects - this is at the heart of Schroedinger's cat paradox - or do gravitation or yet unknown effects set a limit for massive particles? What is the fundamental relation between quantum physics and gravity? Ground-based experiments addressing these questions may soon face limitations due to limited free-fall times and the quality of vacuum and microgravity. The proposed mission Macroscopic Quantum Resonators (MAQRO) may overcome these limitations and allow addressing such fundamental questions. MAQRO harnesses recent developments in quantum optomechanics, high-mass matter-wave interferometry as well as state-of-the-art space technology to push macroscopic quantum experiments towards their ultimate performance limits and to open new horizons for applying quantum technology in space. The main scientific goal is to probe the vastly unexplored 'quantum-classical' transition for increasingly massive objects, testing the predictions of quantum theory for objects in a size and mass regime unachievable in ground-based experiments. The hardware will largely be based on available space technology. Here, we present the MAQRO proposal submitted in response to the 4th Cosmic Vision call for a medium-sized mission (M4) in 2014 of the European Space Agency (ESA) with a possible launch in 2025, and we review the progress with respect to the original MAQRO proposal for the 3rd Cosmic Vision call for a medium-sized mission (M3) in 2010. In particular, the updated proposal overcomes several critical issues of the original proposal by relying on established experimental techniques from high-mass matter-wave interferometry and by introducing novel ideas for particle loading and manipulation. Moreover, the mission design was improved to better fulfill the stringent environmental requirements for macroscopic quantum experiments. (orig.)

  17. A macroscopic approach to creating exotic matter

    OpenAIRE

    Ridgely, C. T.

    2000-01-01

    Herein the Casimir effect is used to present a simple macroscopic view on creating exotic matter. The energy arising between two nearly perfectly conducting parallel plates is shown to become increasingly negative as the plate separation is reduced. It is proposed that the Casimir energy appears increasingly negative simply because the vacuum electromagnetic zero-point field performs positive work in pushing the plates together, transforming field energy into kinetic energy of the plates. Nex...

  18. Shot noise in linear macroscopic resistors

    OpenAIRE

    Gomila Lluch, Gabriel; Pennetta, C.; Reggiani, L.; Ferrari, G; Sampietro, M.; G. Bertuccio(Politecnico di Milano, Italy)

    2004-01-01

    We report on direct experimental evidence of shot noise in a linear macroscopic resistor. The origin of the shot noise comes from the fluctuation of the total number of charge carriers inside the resistor associated with their diffusive motion under the condition that the dielectric relaxation time becomes longer than the dynamic transit time. The present results show that neither potential barriers nor the absence of inelastic scattering are necessary to observe shot noise in electronic devi...

  19. Shot Noise in Linear Macroscopic Resistors

    Science.gov (United States)

    Gomila, G.; Pennetta, C.; Reggiani, L.; Sampietro, M.; Ferrari, G.; Bertuccio, G.

    2004-06-01

    We report on direct experimental evidence of shot noise in a linear macroscopic resistor. The origin of the shot noise comes from the fluctuation of the total number of charge carriers inside the resistor associated with their diffusive motion under the condition that the dielectric relaxation time becomes longer than the dynamic transit time. The present results show that neither potential barriers nor the absence of inelastic scattering are necessary to observe shot noise in electronic devices.

  20. Macroscopic Objects, Intrinsic Spin, and Lorentz Violation

    CERN Document Server

    Atkinson, David W; Tasson, Jay D

    2013-01-01

    The framework of the Standard-Model Extension (SME) provides a relativistic quantum field theory for the study of Lorentz violation. The classical, nonrelativistic equations of motion can be extracted as a limit that is useful in various scenarios. In this work, we consider the effects of certain SME coefficients for Lorentz violation on the motion of macroscopic objects having net intrinsic spin in the classical, nonrelativistic limit.

  1. Active Polar Two-Fluid Macroscopic Dynamics

    Science.gov (United States)

    Pleiner, Harald; Svensek, Daniel; Brand, Helmut R.

    2014-03-01

    We study the dynamics of systems with a polar dynamic preferred direction. Examples include the pattern-forming growth of bacteria (in a solvent, shoals of fish (moving in water currents), flocks of birds and migrating insects (flying in windy air). Because the preferred direction only exists dynamically, but not statically, the macroscopic variable of choice is the macroscopic velocity associated with the motion of the active units. We derive the macroscopic equations for such a system and discuss novel static, reversible and irreversible cross-couplings connected to this second velocity. We find a normal mode structure quite different compared to the static descriptions, as well as linear couplings between (active) flow and e.g. densities and concentrations due to the genuine two-fluid transport derivatives. On the other hand, we get, quite similar to the static case, a direct linear relation between the stress tensor and the structure tensor. This prominent ``active'' term is responsible for many active effects, meaning that our approach can describe those effects as well. In addition, we also deal with explicitly chiral systems, which are important for many active systems. In particular, we find an active flow-induced heat current specific for the dynamic chiral polar order.

  2. The Sulfatase Pathway for Estrogen Formation: Targets for the Treatment and Diagnosis of Hormone-Associated Tumors

    Directory of Open Access Journals (Sweden)

    Lena Secky

    2013-01-01

    Full Text Available The extragonadal synthesis of biological active steroid hormones from their inactive precursors in target tissues is named “intracrinology.” Of particular importance for the progression of estrogen-dependent cancers is the in situ formation of the biological most active estrogen, 17beta-estradiol (E2. In cancer cells, conversion of inactive steroid hormone precursors to E2 is accomplished from inactive, sulfated estrogens in the “sulfatase pathway” and from androgens in the “aromatase pathway.” Here, we provide an overview about expression and function of enzymes of the “sulfatase pathway,” particularly steroid sulfatase (STS that activates estrogens and estrogen sulfotransferase (SULT1E1 that converts active estrone (E1 and other estrogens to their inactive sulfates. High expression of STS and low expression of SULT1E1 will increase levels of active estrogens in malignant tumor cells leading to the stimulation of cell proliferation and cancer progression. Therefore, blocking the “sulfatase pathway” by STS inhibitors may offer an attractive strategy to reduce levels of active estrogens. STS inhibitors either applied in combination with aromatase inhibitors or as novel, dual aromatase-steroid sulfatase inhibiting drugs are currently under investigation. Furthermore, STS inhibitors are also suitable as enzyme–based cancer imaging agents applied in the biomedical imaging technique positron emission tomography (PET for cancer diagnosis.

  3. Establishment and Characterization of Human Germline Stem Cell Line with Unlimited Proliferation Potentials and no Tumor Formation.

    Science.gov (United States)

    Hou, Jingmei; Niu, Minghui; Liu, Linhong; Zhu, Zijue; Wang, Xiaobo; Sun, Min; Yuan, Qingqing; Yang, Shi; Zeng, Wenxian; Liu, Yang; Li, Zheng; He, Zuping

    2015-11-20

    Spermatogonial stem cells (SSCs) have significant applications in both reproductive and regenerative medicine. However, primary human SSCs are very rare, and a human SSC line has not yet been available. In this study, we have for the first time reported a stable human SSC line by stably expressing human SV40 large T antigen. RT-PCR, immunocytochemistry, and Western blots revealed that this cell line was positive for a number of human spermatogonial and SSC hallmarks, including VASA, DAZL, MAGEA4, GFRA1, RET, UCHL1, GPR125, PLZF and THY1, suggesting that these cells are human SSCs phenotypically. Proliferation analysis showed that the cell line could be expanded with significant increases of cells for 1.5 years, and high levels of PCNA, UCHL1 and SV40 were maintained for long-term culture. Transplantation assay indicated that human SSC line was able to colonize and proliferate in vivo in the recipient mice. Neither Y chromosome microdeletions of numerous genes nor tumor formation was observed in human SSC line although there was abnormal karyotype in this cell line. Collectively, we have established a human SSC line with unlimited proliferation potentials and no tumorgenesis, which could provide an abundant source of human SSCs for their mechanistic studies and translational medicine.

  4. Blockage of neddylation modification stimulates tumor sphere formation in vitro and stem cell differentiation and wound healing in vivo.

    Science.gov (United States)

    Zhou, Xiaochen; Tan, Mingjia; Nyati, Mukesh K; Zhao, Yongchao; Wang, Gongxian; Sun, Yi

    2016-05-24

    MLN4924, also known as pevonedistat, is the first-in-class inhibitor of NEDD8-activating enzyme, which blocks the entire neddylation modification of proteins. Previous preclinical studies and current clinical trials have been exclusively focused on its anticancer property. Unexpectedly, we show here, to our knowledge for the first time, that MLN4924, when applied at nanomolar concentrations, significantly stimulates in vitro tumor sphere formation and in vivo tumorigenesis and differentiation of human cancer cells and mouse embryonic stem cells. These stimulatory effects are attributable to (i) c-MYC accumulation via blocking its degradation and (ii) continued activation of EGFR (epidermal growth factor receptor) and its downstream pathways, including PI3K/AKT/mammalian target of rapamycin and RAS/RAF/MEK/ERK, via inducing EGFR dimerization. Finally, MLN4924 accelerates EGF-mediated skin wound healing in mouse and stimulates cell migration in an in vitro culture setting. Taking these data together, our study reveals that neddylation modification could regulate stem cell proliferation and differentiation and that a low dose of MLN4924 might have a therapeutic value for stem cell therapy and tissue regeneration.

  5. COX-2 inhibition is neither necessary nor sufficient for celecoxib to suppress tumor cell proliferation and focus formation in vitro

    Directory of Open Access Journals (Sweden)

    Petasis Nicos A

    2008-05-01

    Full Text Available Abstract Background An increasing number of reports is challenging the notion that the antitumor potential of the selective COX-2 inhibitor celecoxib (Celebrex® is mediated primarily via the inhibition of COX-2. We have investigated this issue by applying two different analogs of celecoxib that differentially display COX-2-inhibitory activity: the first analog, called unmethylated celecoxib (UMC, inhibits COX-2 slightly more potently than its parental compound, whereas the second analog, 2,5-dimethyl-celecoxib (DMC, has lost the ability to inhibit COX-2. Results With the use of glioblastoma and pancreatic carcinoma cell lines, we comparatively analyzed the effects of celecoxib, UMC, and DMC in various short-term (≤48 hours cellular and molecular studies, as well as in long-term (≤3 months focus formation assays. We found that DMC exhibited the most potent antitumor activity; celecoxib was somewhat less effective, and UMC clearly displayed the overall weakest antitumor potential in all aspects. The differential growth-inhibitory and apoptosis-stimulatory potency of these compounds in short-term assays did not at all correlate with their capacity to inhibit COX-2, but was closely aligned with their ability to trigger endoplasmic reticulum stress (ERS, as indicated by the induction of the ERS marker CHOP/GADD153 and activation of the ERS-associated caspase 7. In addition, we found that these compounds were able to restore contact inhibition and block focus formation during long-term, chronic drug exposure of tumor cells, and this was achieved at sub-toxic concentrations in the absence of ERS or inhibition of COX-2. Conclusion The antitumor activity of celecoxib in vitro did not involve the inhibition of COX-2. Rather, the drug's ability to trigger ERS, a known effector of cell death, might provide an alternative explanation for its acute cytotoxicity. In addition, the newly discovered ability of this drug to restore contact inhibition and

  6. Expression of a mutant p53 results in an age-related demographic shift in spontaneous lung tumor formation in transgenic mice.

    Directory of Open Access Journals (Sweden)

    Wenrui Duan

    Full Text Available BACKGROUND: Mutations in the P53 gene are among the most common genetic abnormalities in human lung cancer. Codon 273 in the sequence-specific DNA binding domain is one of the most frequently mutated sites. METHODOLOGY: To investigate the role of mutant p53 in lung tumorigenesis, a lung specific p53(273H transgenic mouse model was developed. Rates of lung cancer formation in the transgenic animals and their littermates were evaluated by necropsy studies performed in progressive age cohorts ranging from 4 to 24 months. In order to establish the influence of other common genetic abnormalities in lung tumor formation in the animals, K-Ras gene mutation and p16INK4a (p16 promoter methylation were evaluated in a total of 281 transgenic mice and 189 non-transgenic littermates. PRINCIPAL FINDINGS: At the age extremes of 4-12 and 22-24 months no differences were observed, with very low prevalence of tumors in animals younger than 12 months, and a relatively high prevalence at age 22 months or older. However, the transgenic mice had a significant higher lung tumor rate than their non-transgenic counterparts during the age of 13-21 months, suggesting an age-related shift in lung tumor formation induced by the lung-specific expression of the human mutant p53. Histopathology suggested a more aggressive nature for the transgenic tumors. Older mice (>13 months had a significantly higher rate of p16 promoter methylation (17% v 82%. In addition, an age related effect was observed for K-Ras codons 12 or 13 mutations, but not for codon 61 mutations. CONCLUSIONS/SIGNIFICANCE: These results would suggest that the mutant p53(273H contributes to an acceleration in the development of spontaneous lung tumors in these mice. Combination with other genetic and epigenetic alterations occurring after the age of 13 months is intimately linked to its oncogenic potential.

  7. Mifepristone-inducible caspase-1 expression in mouse embryonic stem cells eliminates tumor formation but spares differentiated cells in vitro and in vivo.

    Science.gov (United States)

    Wang, Yi; Yang, Dehua; Song, Lin; Li, Ting; Yang, Juan; Zhang, Xiaojie; Le, Weidong

    2012-02-01

    Embryonic stem cell (ESC)-based therapy is a promising treatment for neurodegenerative diseases. But there is always a risk of tumor formation that is due to contamination of undifferentiated ESCs. To reduce the risk and improve ESC-based therapy, we have established a novel strategy by which we can selectively eliminate tumor cells derived from undifferentiated ESCs but spare differentiated cells. In this study, we generated a caspase-1-ESC line transfected with a mifepristone-regulated caspase-1 expression system. Mifepristone induced caspase-1 overexpression both in differentiated and undifferentiated caspase-1-ESCs. All the undifferentiated caspase-1-ESCs were induced to death after mifepristone treatment. Tumors derived from undifferentiated caspase-1-ESCs were eliminated following 3 weeks of mifepristone treatment in vivo. However, differentiated caspase-1-ESCs survived well under the condition of mifepristone-induced caspase-1 overexpression. To examine in vivo the impact of mifepristone-induced caspase-1 activation on grafted cells, we transplanted wild-type ESCs or caspase-1-ESCs into nude mice brains. After 8 weeks of mifepristone treatment, we could not detect any tumor cells in the caspase-1-ESC grafts in the brains of mice. However, we found that donor dopamine neurons survived in the recipient brains. These data demonstrate that mifepristone-induced caspase-1 overexpression in ESCs can eliminate the potential tumor formation meanwhile spares the differentiated cells in the host brains. These results suggest that this novel ESC-based therapy can be used in Parkinson's disease and other related disorders without the risk of tumor formation.

  8. Lymphoepithelioma-like esophageal carcinoma with macroscopic reduction

    Institute of Scientific and Technical Information of China (English)

    Masaya; Uesato; Tuguaki; Kono; Tooru; Shiratori; Yasunori; Akutsu; Isamu; Hoshino; Kentarou; Murakami; Daisuke; Horibe; Tetsurou; Maruyama; Yoshihide; Semba; Ryuma; Urahama; Yukiko; Ogura; Takashi; Oide; Toru; Tanizawa; Hisahiro; Matsubara

    2014-01-01

    Esophageal lymphoepithelioma-like carcinoma(LELC) is extremely rare. We report the first case of esopha-geal LELC showing macroscopic reduction. A 67-year-old male presented with dysphagia and, by endoscopic examination, was found to have a significantly raised tumor of 10 mm in diameter in the thoracic esophagus. The biopsied material showed esophageal cancer. We performed endoscopic submucosal dissection. However, the tumor became flattened, similar to a scar, in only 2 mo. Histologically, the carcinoma cells had infiltrated the submucosal layer. Prominent infiltration of T lymphoid cells that stained positive for CD8 was observed aroundthe carcinoma cells. Therefore, this lesion was consid-ered to be an LELC with poorly differentiated squamous cells. Because the margin was positive, an esophagec-tomy was performed. Carcinoma cells were detected in the neck in one lymph node. The staging was T1N0M1 b. However, the patient has been well, without adjuvant therapy or recurrence, for more than 5 years.

  9. Consensus diagnoses and mode of action for the formation of gastric tumors in rats treated with the chloroacetanilide herbicides alachlor and butachlor.

    Science.gov (United States)

    Furukawa, Satoshi; Harada, Takanori; Thake, Daryl; Iatropoulos, Michael J; Sherman, James H

    2014-01-01

    A panel of pathologists (Panel) was formed to evaluate the pathogenesis and human relevance of tumors that developed in the fundic region of rat stomachs in carcinogenicity and mechanistic studies with alachlor and butachlor. The Panel evaluated stomach sections stained with hematoxylin and eosin, neuron-specific enolase, and chromogranin A to determine the presence and relative proportion of enterochromaffin-like (ECL) cells in the tumors and concluded all tumors were derived from ECL cells. Biochemical and pathological data demonstrated the tumor formation involved a nongenotoxic threshold mode of action (MOA) initially characterized by profound atrophy of the glandular fundic mucosa that affected gastric glands, but not surface epithelium. This resulted in a substantial loss of parietal cells and a compensatory mucosal cell proliferation. The loss of parietal cells caused a marked increase in gastric pH (hypochlorhydria), leading to sustained and profound hypergastrinemia. The mucosal atrophy, together with the increased gastrin, stimulated cell growth in one or more ECL cell populations, resulting in neoplasia. ECL cell autocrine and paracrine effects led to dedifferentiation of ECL cell tumors. The Panel concluded the tumors develop via a threshold-dependent nongenotoxic MOA, under conditions not relevant to humans.

  10. Self-feeding turbulent magnetic reconnection on macroscopic scales.

    Science.gov (United States)

    Lapenta, Giovanni

    2008-06-13

    Within a MHD approach we find magnetic reconnection to progress in two entirely different ways. The first is well known: the laminar Sweet-Parker process. But a second, completely different and chaotic reconnection process is possible. This regime has properties of immediate practical relevance: (i) it is much faster, developing on scales of the order of the Alfvén time, and (ii) the areas of reconnection become distributed chaotically over a macroscopic region. The onset of the faster process is the formation of closed-circulation patterns where the jets going out of the reconnection regions turn around and force their way back in, carrying along copious amounts of magnetic flux.

  11. Distinct molecular features of different macroscopic subtypes of colorectal neoplasms.

    Directory of Open Access Journals (Sweden)

    Kenichi Konda

    Full Text Available BACKGROUND: Colorectal adenoma develops into cancer with the accumulation of genetic and epigenetic changes. We studied the underlying molecular and clinicopathological features to better understand the heterogeneity of colorectal neoplasms (CRNs. METHODS: We evaluated both genetic (mutations of KRAS, BRAF, TP53, and PIK3CA, and microsatellite instability [MSI] and epigenetic (methylation status of nine genes or sequences, including the CpG island methylator phenotype [CIMP] markers alterations in 158 CRNs including 56 polypoid neoplasms (PNs, 25 granular type laterally spreading tumors (LST-Gs, 48 non-granular type LSTs (LST-NGs, 19 depressed neoplasms (DNs and 10 small flat-elevated neoplasms (S-FNs on the basis of macroscopic appearance. RESULTS: S-FNs showed few molecular changes except SFRP1 methylation. Significant differences in the frequency of KRAS mutations were observed among subtypes (68% for LST-Gs, 36% for PNs, 16% for DNs and 6% for LST-NGs (P<0.001. By contrast, the frequency of TP53 mutation was higher in DNs than PNs or LST-Gs (32% vs. 5% or 0%, respectively (P<0.007. We also observed significant differences in the frequency of CIMP between LST-Gs and LST-NGs or PNs (32% vs. 6% or 5%, respectively (P<0.005. Moreover, the methylation level of LINE-1 was significantly lower in DNs or LST-Gs than in PNs (58.3% or 60.5% vs. 63.2%, P<0.05. PIK3CA mutations were detected only in LSTs. Finally, multivariate analyses showed that macroscopic morphologies were significantly associated with an increased risk of molecular changes (PN or LST-G for KRAS mutation, odds ratio [OR] 9.11; LST-NG or DN for TP53 mutation, OR 5.30; LST-G for PIK3CA mutation, OR 26.53; LST-G or DN for LINE-1 hypomethylation, OR 3.41. CONCLUSION: We demonstrated that CRNs could be classified into five macroscopic subtypes according to clinicopathological and molecular differences, suggesting that different mechanisms are involved in the pathogenesis of colorectal

  12. Rainbow correlation imaging with macroscopic twin beam

    Science.gov (United States)

    Allevi, Alessia; Bondani, Maria

    2017-06-01

    We present the implementation of a correlation-imaging protocol that exploits both the spatial and spectral correlations of macroscopic twin-beam states generated by parametric downconversion. In particular, the spectral resolution of an imaging spectrometer coupled to an EMCCD camera is used in a proof-of-principle experiment to encrypt and decrypt a simple code to be transmitted between two parties. In order to optimize the trade-off between visibility and resolution, we provide the characterization of the correlation images as a function of the spatio-spectral properties of twin beams generated at different pump power values.

  13. Fingerprint Feature Extraction Based on Macroscopic Curvature

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiong; He Gui-ming; Zhang Yun

    2003-01-01

    In the Automatic Fingerprint Identification System (AFIS), extracting the feature of fingerprint is very important. The local curvature of ridges of fingerprint is irregular, so people have the barrier to effectively extract the fingerprint curve features to describe fingerprint. This article proposes a novel algorithm; it embraces information of few nearby fingerprint ridges to extract a new characteristic which can describe the curvature feature of fingerprint. Experimental results show the algorithm is feasible, and the characteristics extracted by it can clearly show the inner macroscopic curve properties of fingerprint. The result also shows that this kind of characteristic is robust to noise and pollution.

  14. Fingerprint Feature Extraction Based on Macroscopic Curvature

    Institute of Scientific and Technical Information of China (English)

    Zhang; Xiong; He; Gui-Ming; 等

    2003-01-01

    In the Automatic Fingerprint Identification System(AFIS), extracting the feature of fingerprint is very important. The local curvature of ridges of fingerprint is irregular, so people have the barrier to effectively extract the fingerprint curve features to describe fingerprint. This article proposes a novel algorithm; it embraces information of few nearby fingerprint ridges to extract a new characterstic which can describe the curvature feature of fingerprint. Experimental results show the algorithm is feasible, and the characteristics extracted by it can clearly show the inner macroscopic curve properties of fingerprint. The result also shows that this kind of characteristic is robust to noise and pollution.

  15. Macroscopic Quantum Criticality in a Circuit QED

    CERN Document Server

    Wang, Y D; Nori, F; Quan, H T; Sun, C P; Liu, Yu-xi; Nori, Franco

    2006-01-01

    Cavity quantum electrodynamic (QED) is studied for two strongly-coupled charge qubits interacting with a single-mode quantized field, which is provided by a on-chip transmission line resonator. We analyze the dressed state structure of this superconducting circuit QED system and the selection rules of electromagnetic-induced transitions between any two of these dressed states. Its macroscopic quantum criticality, in the form of ground state level crossing, is also analyzed, resulting from competition between the Ising-type inter-qubit coupling and the controllable on-site potentials.

  16. Macroscopic fluctuations theory of aerogel dynamics

    CERN Document Server

    Lefevere, Raphael; Zambotti, Lorenzo

    2010-01-01

    We consider extensive deterministic dynamics made of $N$ particles modeling aerogels under a macroscopic fluctuation theory description. By using a stochastic model describing those dynamics after a diffusive rescaling, we show that the functional giving the exponential decay in $N$ of the probability of observing a given energy and current profile is not strictly convex as a function of the current. This behaviour is caused by the fact that the energy current is carried by particles which may have arbitrary low speed with sufficiently large probability.

  17. Placenta growth factor-1 antagonizes VEGF-induced angiogenesis and tumor growth by the formation of functionally inactive PIGF-1/VEGF heterodimers

    DEFF Research Database (Denmark)

    Eriksson, A.; Cao, R.; Pawliuk, R.

    2002-01-01

    , the biological function of its related homolog, placenta growth factor (PlGF), is poorly understood. Here we demonstrate that PlGF-1, an alternatively spliced isoform of the PlGF gene, antagonizes VEGF-induced angiogenesis when both factors are coexpressed in murine fibrosarcoma cells. Overexpression of PlGF-1...... in VEGF-producing tumor cells results in the formation of PlGF-1/VEGF heterodimers and depletion of the majority of mouse VEGF homodimers. The heterodimeric form of PlGF-1/VEGF lacks the ability to induce angiogenesis in vitro and in vivo. Similarly, PlGF-1/VEGF fails to activate the VEGFR-2-mediated...... signaling pathways. Further, PlGF-1 inhibits the growth of a murine fibrosarcoma by approximately 90% when PlGF-1-expressing tumor cells are implanted in syngeneic mice. In contrast, overexpression of human VEGF in murine tumor cells causes accelerated and exponential growth of primary fibrosarcomas...

  18. Spin models as microfoundation of macroscopic market models

    Science.gov (United States)

    Krause, Sebastian M.; Bornholdt, Stefan

    2013-09-01

    Macroscopic price evolution models are commonly used for investment strategies. There are first promising achievements in defining microscopic agent based models for the same purpose. Microscopic models allow a deeper understanding of mechanisms in the market than the purely phenomenological macroscopic models, and thus bear the chance for better models for market regulation. However microscopic models and macroscopic models are commonly studied separately. Here, we exemplify a unified view of a microscopic and a macroscopic market model in a case study, deducing a macroscopic Langevin equation from a microscopic spin market model closely related to the Ising model. The interplay of the microscopic and the macroscopic view allows for a better understanding and adjustment of the microscopic model, as well, and may guide the construction of agent based market models as basis of macroscopic models.

  19. Innovations in macroscopic evaluation of pancreatic specimens and radiologic correlation

    Directory of Open Access Journals (Sweden)

    Charikleia Triantopoulou

    2016-01-01

    Full Text Available The purpose of this study was to evaluate the feasibility of a novel dissection technique of surgical specimens in different cases of pancreatic tumors and provide a radiologic pathologic correlation. In our hospital, that is a referral center for pancreatic diseases, the macroscopic evaluation of the pancreatectomy specimens is performed by the pathologists using the axial slicing technique (instead of the traditional procedure with longitudinal opening of the main pancreatic and/or common bile duct and slicing along the plane defined by both ducts. The specimen is sliced in an axial plane that is perpendicular to the longitudinal axis of the descending duodenum. The procedure results in a large number of thin slices (3–4 mm. This plane is identical to that of CT or MRI and correlation between pathology and imaging is straightforward. We studied 70 cases of suspected different solid and cystic pancreatic tumors and we correlated the tumor size and location, the structure—consistency (areas of necrosis—hemorrhage—fibrosis—inflammation, the degree of vessels’ infiltration, the size of pancreatic and common bile duct and the distance from resection margins. Missed findings by imaging or pitfalls were recorded and we tried to explain all discrepancies between radiology evaluation and the histopathological findings. Radiologic-pathologic correlation is extremely important, adding crucial information on imaging limitations and enabling quality assessment of surgical specimens. The deep knowledge of different pancreatic tumors’ consistency and way of extension helps to improve radiologists’ diagnostic accuracy and minimize the radiological-surgical mismatching, preventing patients from unnecessary surgery.

  20. Silencing BMI1 eliminates tumor formation of pediatric glioma CD133+ cells not by affecting known targets but by down-regulating a novel set of core genes.

    Science.gov (United States)

    Baxter, Patricia A; Lin, Qi; Mao, Hua; Kogiso, Mari; Zhao, Xiumei; Liu, Zhigang; Huang, Yulun; Voicu, Horatiu; Gurusiddappa, Sivashankarappa; Su, Jack M; Adesina, Adekunle M; Perlaky, Laszlo; Dauser, Robert C; Leung, Hon-chiu Eastwood; Muraszko, Karin M; Heth, Jason A; Fan, Xing; Lau, Ching C; Man, Tsz-Kwong; Chintagumpala, Murali; Li, Xiao-Nan

    2014-01-01

    Clinical outcome of children with malignant glioma remains dismal. Here, we examined the role of over-expressed BMI1, a regulator of stem cell self-renewal, in sustaining tumor formation in pediatric glioma stem cells. Our investigation revealed BMI1 over-expression in 29 of 54 (53.7%) pediatric gliomas, 8 of 8 (100%) patient derived orthotopic xenograft (PDOX) mouse models, and in both CD133+ and CD133- glioma cells. We demonstrated that lentiviral-shRNA mediated silencing of suppressed cell proliferation in vitro in cells derived from 3 independent PDOX models and eliminated tumor-forming capacity of CD133+ and CD133- cells derived from 2 PDOX models in mouse brains. Gene expression profiling showed that most of the molecular targets of BMI1 ablation in CD133+ cells were different from that in CD133- cells. Importantly, we found that silencing BMI1 in CD133+ cells derived from 3 PDOX models did not affect most of the known genes previously associated with the activated BMI1, but modulated a novel set of core genes, including RPS6KA2, ALDH3A2, FMFB, DTL, API5, EIF4G2, KIF5c, LOC650152, C20ORF121, LOC203547, LOC653308, and LOC642489, to mediate the elimination of tumor formation. In summary, we identified the over-expressed BMI1 as a promising therapeutic target for glioma stem cells, and suggest that the signaling pathways associated with activated BMI1 in promoting tumor growth may be different from those induced by silencing BMI1 in blocking tumor formation. These findings highlighted the importance of careful re-analysis of the affected genes following the inhibition of abnormally activated oncogenic pathways to identify determinants that can potentially predict therapeutic efficacy.

  1. Formats

    Directory of Open Access Journals (Sweden)

    Gehmann, Ulrich

    2012-03-01

    Full Text Available In the following, a new conceptual framework for investigating nowadays’ “technical” phenomena shall be introduced, that of formats. The thesis is that processes of formatting account for our recent conditions of life, and will do so in the very next future. It are processes whose foundations have been laid in modernity and which will further unfold for the time being. These processes are embedded in the format of the value chain, a circumstance making them resilient to change. In addition, they are resilient in themselves since forming interconnected systems of reciprocal causal circuits.Which leads to an overall situation that our entire “Lebenswelt” became formatted to an extent we don’t fully realize, even influencing our very percep-tion of it.

  2. MACROSCOPIC STRAIN POTENTIALS IN NONLINEAR POROUS MATERIALS

    Institute of Scientific and Technical Information of China (English)

    刘熠; 黄筑平

    2003-01-01

    By taking a hollow sphere as a representative volume element (RVE), the macroscopic strain potentials of porous materials with power-law incompressible matrix are studied in this paper.According to the principles of the minimum potential energy in nonlinear elasticity and the variational procedure, static admissible stress fields and kinematic admissible displacement fields are constructed,and hence the upper and the lower bounds of the macroscopic strain potential are obtained. The bounds given in the present paper differ so slightly that they both provide perfect approximations of the exact strain potential of the studied porous materials. It is also found that the upper bound proposed by previous authors is much higher than the present one, and the lower bounds given by Cocks is much lower. Moreover, the present calculation is also compared with the variational lower bound of Ponte Castafneda for statistically isotropic porous materials. Finally, the validity of the hollow spherical RVE for the studied nonlinear porous material is discussed by the difference between the present numerical results and the Cocks bound.

  3. Macroscopic theory for capillary-pressure hysteresis.

    Science.gov (United States)

    Athukorallage, Bhagya; Aulisa, Eugenio; Iyer, Ram; Zhang, Larry

    2015-03-03

    In this article, we present a theory of macroscopic contact angle hysteresis by considering the minimization of the Helmholtz free energy of a solid-liquid-gas system over a convex set, subject to a constant volume constraint. The liquid and solid surfaces in contact are assumed to adhere weakly to each other, causing the interfacial energy to be set-valued. A simple calculus of variations argument for the minimization of the Helmholtz energy leads to the Young-Laplace equation for the drop surface in contact with the gas and a variational inequality that yields contact angle hysteresis for advancing/receding flow. We also show that the Young-Laplace equation with a Dirichlet boundary condition together with the variational inequality yields a basic hysteresis operator that describes the relationship between capillary pressure and volume. We validate the theory using results from the experiment for a sessile macroscopic drop. Although the capillary effect is a complex phenomenon even for a droplet as various points along the contact line might be pinned, the capillary pressure and volume of the drop are scalar variables that encapsulate the global quasistatic energy information for the entire droplet. Studying the capillary pressure versus volume relationship greatly simplifies the understanding and modeling of the phenomenon just as scalar magnetic hysteresis graphs greatly aided the modeling of devices with magnetic materials.

  4. Inhibitory Effect of a γ-Tocopherol-Rich Mixture of Tocopherols on the Formation and Growth of LNCaP Prostate Tumors in Immunodeficient Mice

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xi, E-mail: xizheng@rci.rutgers.edu [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States); Cui, Xiao-Xing [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Khor, Tin Oo; Huang, Ying [Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); DiPaola, Robert S; Goodin, Susan [Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States); Lee, Mao-Jung [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Yang, Chung S [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States); Kong, Ah-Ng [Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States); Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Allan H, Conney [Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 164 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Cancer Institute of New Jersey, New Brunswick, NJ 08903 (United States)

    2011-09-28

    In the present study, we determined the effects of a γ-tocopherol-rich mixture of tocopherols (γ-TmT) on the growth and apoptosis of cultured human prostate cancer LNCaP cells. We also determined the effects of dietary γ-TmT on the formation and growth of LNCaP tumors in immunodeficient mice. In the in vitro study, we found that the activity of γ-TmT was stronger than α-tocopherol for inhibiting the growth and stimulating apoptosis in LNCaP cells. In the animal study, treatment of severe combined immunodeficient (SCID) mice with dietary γ-TmT inhibited the formation and growth of LNCaP xenograft tumors in a dose-dependent manner. Mechanistic studies showed that γ-TmT administration inhibited proliferation as reflected by decreased mitosis and stimulated apoptosis as reflected by increased caspase-3 (active form) expression in LNCaP tumors. In addition, dietary administration of γ-TmT increased the levels of α-, γ- and δ- tocopherol in plasma, and increased levels of γ- and δ- tocopherol were also observed in the prostate and in tumors. The present study demonstrated that γ-TmT had strong anticancer activity both in vitro and in vivo. Additional studies are needed to determine the potential preventive effect of γ-TmT for prostate cancer in humans.

  5. Quantum correlations of lights in macroscopic environments

    Science.gov (United States)

    Sua, Yong Meng

    This dissertation presents a detailed study in exploring quantum correlations of lights in macroscopic environments. We have explored quantum correlations of single photons, weak coherent states, and polarization-correlated/polarization-entangled photons in macroscopic environments. These included macroscopic mirrors, macroscopic photon number, spatially separated observers, noisy photons source and propagation medium with loss or disturbances. We proposed a measurement scheme for observing quantum correlations and entanglement in the spatial properties of two macroscopic mirrors using single photons spatial compass state. We explored the phase space distribution features of spatial compass states, such as chessboard pattern by using the Wigner function. The displacement and tilt correlations of the two mirrors were manifested through the propensities of the compass states. This technique can be used to extract Einstein-Podolsky-Rosen correlations (EPR) of the two mirrors. We then formulated the discrete-like property of the propensity P b(m,n), which can be used to explore environmental perturbed quantum jumps of the EPR correlations in phase space. With single photons spatial compass state, the variances in position and momentum are much smaller than standard quantum limit when using a Gaussian TEM 00 beam. We observed intrinsic quantum correlations of weak coherent states between two parties through balanced homodyne detection. Our scheme can be used as a supplement to decoy-state BB84 protocol and differential phase-shift QKD protocol. We prepared four types of bipartite correlations +/- cos2(theta1 +/- theta 2) that shared between two parties. We also demonstrated bits correlations between two parties separated by 10 km optical fiber. The bits information will be protected by the large quantum phase fluctuation of weak coherent states, adding another physical layer of security to these protocols for quantum key distribution. Using 10 m of highly nonlinear

  6. Formation and utilization of acetoin, an unusual product of pyruvate metabolism by Ehrlich and AS30-D tumor mitochondria.

    Science.gov (United States)

    Baggetto, L G; Lehninger, A L

    1987-07-15

    [14C]Pyruvate was rapidly non-oxidatively decarboxylated by Ehrlich tumor mitochondria at a rate of 40 nmol/min/mg of protein in the presence or absence of ADP. A search for decarboxylation products led to significant amounts of acetoin formed when Ehrlich tumor mitochondria were incubated with 1 mM [14C] pyruvate in the presence of ATP. Added acetoin to aerobic tumor mitochondria was rapidly utilized in the presence of ATP at a rate of 65 nmol/min/mg of protein. Citrate has been found as a product of acetoin utilization and was exported from the tumor mitochondria. Acetoin has been found in the ascitic liquid of Ehrlich and AS30-D tumor-bearing animals. These unusual reactions were not observed in control rat liver mitochondria.

  7. Inhibitory effect of parvovirus H—1 on the formation of colonies of human hepatoma cell line in vitro and its tumors in nude mice

    Institute of Scientific and Technical Information of China (English)

    YANSHANGJUN; CHENGWUMA; 等

    1994-01-01

    The inhibitory effect of parvovirus H-1 on the colonyforming ability.in vitro of QGY-7703,a cultured human hepatoma cell line,and on the formation and growth of its tumors in nude mice was studied.With higher multiplicity of infection(MOI) of H-1 given,survival of the QGY-7703 cells was found to be decreased.H-1 DNA amplification level at 30h postinfection(p.i.) was detected to be 7.4 times higher than that at 2h by dispersed cells assay,while the cells were delayed to enter into S phase.Plaques were formed in the indicator cells(new-born human kidney cell line,NBK) by progeny H-1 virus particles released from the infected QGY-7703 cells by infectious cell center assay.The formation of tumors in nude mice by QGY-7703 cells which were injected s c at 2h postinfection was observed to by prevented in 2 proups with given MOI 25 and 50.The tumor growth of MOI 10 group occurred at a lower exponential rate than that of control,after a 20d latent period.It was evident that parvovirus H-1 exhibited a direct inhibitory effect on the formation and growth of human hepatoma cells in vivo as well as in vitro.

  8. Analysis of Dose at the Site of Second Tumor Formation After Radiotherapy to the Central Nervous System

    Energy Technology Data Exchange (ETDEWEB)

    Galloway, Thomas J. [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL (United States); University of Florida Proton Therapy Institute, Jacksonville, FL (United States); Indelicato, Daniel J., E-mail: dindelicato@floridaproton.org [University of Florida Proton Therapy Institute, Jacksonville, FL (United States); Amdur, Robert J.; Morris, Christopher G.; Swanson, Erika L. [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL (United States); Marcus, Robert B. [University of Florida Proton Therapy Institute, Jacksonville, FL (United States)

    2012-01-01

    Purpose: Second tumors are an uncommon complication of multimodality treatment of childhood cancer. The present analysis attempted to correlate the dose received as a component of primary treatment and the site of the eventual development of a second tumor. Methods and Materials: We retrospectively identified 16 patients who had received radiotherapy to sites in the craniospinal axis and subsequently developed a second tumor. We compared the historical fields and port films of the primary treatment with the modern imaging of the second tumor locations. We classified the location of the second tumors as follows: in the boost field; marginal to the boost field, but in a whole-brain field; in a whole-brain field; marginal to the whole brain/primary treatment field; and distant to the field. We divided the dose received into 3 broad categories: high dose (>45 Gy), moderate dose (20-36 Gy), and low dose (<20 Gy). Results: The most common location of the second tumor was in the whole brain field (57%) and in the moderate-dose range (81%). Conclusions: Our data contradict previous publications that suggested that most second tumors develop in tissues that receive a low radiation dose. Almost all the second tumors in our series occurred in tissue within a target volume in the cranium that had received a moderate dose (20-36 Gy). These findings suggest that a major decrease in the brain volume that receives a moderate radiation dose is the only way to substantially decrease the second tumor rate after central nervous system radiotherapy.

  9. Neuropilin-1 is expressed by breast cancer stem-like cells and is linked to NF-κB activation and tumor sphere formation.

    Science.gov (United States)

    Glinka, Yelena; Mohammed, Nada; Subramaniam, Venkateswaran; Jothy, Serge; Prud'homme, Gérald J

    2012-09-07

    Cancer stem cells (CSCs) initiate tumors and have a high resistance to conventional cancer therapy. Tranilast is an orally active drug of low toxicity that exerts inhibitory effects on breast CSCs. This appears to depend on its aryl hydrocarbon receptor (AHR) agonistic activity, but this receptor has diverse functions and it is unclear how CSCs are inhibited. CSCs generate tumor spheres in low-adherence cultures, and we employed the mammosphere-forming assay as a functional test for breast CSCs. Because NF-κB has a key role in mammosphere formation and CSC-mediated tumor initiation, we examined that pathway. We also examined the role of neuropilin-1 (Nrp1), which is a growth factor coreceptor linked to the tumorigenicity of some CSCs. We found that tranilast concurrently suppressed mammosphere formation, Nrp1 expression and constitutive NF-κB activation. Flow cytometric analysis revealed that a subpopulation of breast cancer cells bearing breast CSC markers also expressed Nrp1. A blocking anti-Nrp1 antibody suppressed mammosphere formation. We examined whether there was a link between Nrp1 and NF-κB activation. The siRNA knockdown of Nrp1 severely suppressed NF-κB activation and mammosphere formation. The phosphorylation of Akt and ERK1/2 was also reduced, but to a lesser extent. We conclude that Nrp1 plays a key role in mammosphere formation and this activity is linked to NF-κB activation. Thus, Nrp1 might be a target for therapy against breast CSCs, and the anticancer drug tranilast suppresses its expression. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Analysis of macroscopic and microscopic rotating motions in rotating jets: A direct numerical simulation

    Directory of Open Access Journals (Sweden)

    Xingtuan Yang

    2015-05-01

    Full Text Available A direct numerical simulation study of the characteristics of macroscopic and microscopic rotating motions in swirling jets confined in a rectangular flow domain is carried out. The different structures of vortex cores for different swirl levels are illustrated. It is found that the vortex cores of low swirl flows are of regular cylindrical-helix patterns, whereas those of the high swirl flows are characterized by the formation of the bubble-type vortex breakdown followed by the radiant processing vortex cores. The results of mean velocity fields show the general procedures of vortex origination. Moreover, the effects of macroscopic and microscopic rotating motions with respect to the mean and fluctuation fields of the swirling flows are evaluated. The microscopic rotating effects, especially the effects with respect to the turbulent fluctuation motion, are increasingly intermittent with the increase in the swirl levels. In contrast, the maximum value of the probability density functions with respect to the macroscopic rotating effects of the fluctuation motion occurs at moderate swirl levels since the macroscopic rotating effects are attenuated by the formation of the bubble vortex breakdown with a region of stagnant fluids at supercritical swirl levels.

  11. Macroscopic Quantum Coherence in Antiferromagnetic Molecular Magnets

    Institute of Scientific and Technical Information of China (English)

    HU Hui; LO Rong; ZHU Jia-Lin; XIONG Jia-Jiong

    2001-01-01

    The macroscopic quantum coherence in a biaxial antiferromagnetic molecular magnet in the presence of magnetic field acting parallel to its hard anisotropy axis is studied within the two-sublattice model. On the basis of instanton technique in the spin-coherent-state path-integral representation, both the rigorous Wentzel-Kramers-Brillouin exponent and pre-exponential factor for the ground-state tunnel splitting are obtained. We find that the quantum fluctuations around the classical paths can not only induce a new quantum phase previously reported by Chiolero and Loss (Phys. Rev. Lett. 80 (1998) 169), but also have great influence on the intensity of the ground-state tunnel splitting. Those features clearly have no analogue in the ferromagnetic molecular magnets. We suggest that they may be the universal behaviors in all antiferromagnetic molecular magnets. The analytical results are complemented by exact diagonalization calculation.

  12. Micro- and macroscopic simulation of periodic metamaterials

    Directory of Open Access Journals (Sweden)

    R. Schuhmann

    2008-05-01

    Full Text Available In order to characterize three-dimensional, left-handed metamaterials (LHM we use electromagnetic field simulations of unit cells. For waves traveling in one of the main directions of the periodic LHM-arrays, the analysis is concentrated on the calculation of global quantities of the unit cells, such as scattering parameters or dispersion diagrams, and a careful interpretation of the results. We show that the concept of equivalent material values – which may be negative in a narrow frequency range – can be validated by large "global" simulations of a wedge structure. We also discuss the limitations of this concept, since in some cases the macroscopic behavior of an LHM cannot be accurately described by equivalent material values.

  13. Microscopic versus macroscopic calculation of dielectric nanospheres

    Science.gov (United States)

    Kühn, M.; Kliem, H.

    2008-12-01

    The issue of nanodielectrics has recently become an important field of interest. The term describes nanometric dielectrics, i. e. dielectric materials with structural dimensions typically smaller than 100 run. In contrast to the behaviour of a bulk material the nanodielectrics can behave completely different. With shrinking dimensions the surface or rather boundary effects outweigh the volume effects. This leads to a different observable physics at the nanoscale. A crucial point is the question whether a continuum model for the calculation of dielectric properties is still applicable for these nanomaterials. In order to answer this question we simulated dielectric nanospheres with a microscopic local field method and compared the results to the macroscopic mean field theory.

  14. Partitioning a macroscopic system into independent subsystems

    Science.gov (United States)

    Delle Site, Luigi; Ciccotti, Giovanni; Hartmann, Carsten

    2017-08-01

    We discuss the problem of partitioning a macroscopic system into a collection of independent subsystems. The partitioning of a system into replica-like subsystems is nowadays a subject of major interest in several fields of theoretical and applied physics. The thermodynamic approach currently favoured by practitioners is based on a phenomenological definition of an interface energy associated with the partition, due to a lack of easily computable expressions for a microscopic (i.e. particle-based) interface energy. In this article, we outline a general approach to derive sharp and computable bounds for the interface free energy in terms of microscopic statistical quantities. We discuss potential applications in nanothermodynamics and outline possible future directions.

  15. Casimir effect from macroscopic quantum electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Philbin, T G, E-mail: tgp3@st-andrews.ac.uk [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)

    2011-06-15

    The canonical quantization of macroscopic electromagnetism was recently presented in (Philbin 2010 New J. Phys. 12 123008). This theory is used here to derive the Casimir effect, by considering the special case of thermal and zero-point fields. The stress-energy-momentum tensor of the canonical theory follows from Noether's theorem, and its electromagnetic part in thermal equilibrium gives the Casimir energy density and stress tensor. The results hold for arbitrary inhomogeneous magnetodielectrics and are obtained from a rigorous quantization of electromagnetism in dispersive, dissipative media. Continuing doubts about the status of the standard Lifshitz theory as a proper quantum treatment of Casimir forces do not apply to the derivation given here. Moreover, the correct expressions for the Casimir energy density and stress tensor inside media follow automatically from the simple restriction to thermal equilibrium, without the need for complicated thermodynamical or mechanical arguments.

  16. Taming macroscopic jamming in transportation networks

    CERN Document Server

    Ezaki, Takahiro; Nishinari, Katsuhiro

    2015-01-01

    In transportation networks, a spontaneous jamming transition is often observed, e.g in urban road networks and airport networks. Because of this instability, flow distribution is significantly imbalanced on a macroscopic level. To mitigate the congestion, we consider a simple control method, in which congested nodes are closed temporarily, and investigate how it influences the overall system. Depending on the timing of the node closure and opening, and congestion level of a network, the system displays three different phases: free-flow phase, controlled phase, and deadlock phase. We show that when the system is in the controlled phase, the average flow is significantly improved, whereas when in the deadlock phase, the flow drops to zero. We study how the control method increases the network flow and obtain their transition boundary analytically.

  17. Black Holes and Quantumness on Macroscopic Scales

    CERN Document Server

    Flassig, D; Wintergerst, N

    2012-01-01

    It has recently been suggested that black holes may be described as condensates of weakly interacting gravitons at a critical point, exhibiting strong quantum effects. In this paper, we study a model system of attractive bosons in one spatial dimension which is known to undergo a quantum phase transition. We demonstrate explicitly that indeed quantum effects are important at the critical point, even if the number of particles is macroscopic. Most prominently, we evaluate the entropy of entanglement between different momentum modes and observe it to become maximal at the critical point. Furthermore, we explicitly see that the leading entanglement is between long wavelength modes and is hence a feature independent of ultraviolet physics. If applicable to black holes, our findings substantiate the conjectured breakdown of semiclassical physics even for large black holes. This can resolve long standing mysteries, such as the information paradox and the no-hair theorem.

  18. Variability of macroscopic dimensions of Moso bamboo.

    Science.gov (United States)

    Cui, Le; Peng, Wanxi; Sun, Zhengjun; Sun, Zhengjun; Sun, Zhengjun; Lu, Huangfei; Chen, Guoning

    2015-03-01

    In order to the macroscopic geometry distributions of vascular bundles in Moso bamboo tubes. The circumference of bamboo tubes was measured, used a simple quadratic diameter formula to analyze the differences between the tubes in bamboo culm, and the arrangement of vascular bundles was investigated by cross sectional images of bamboo tubes. The results shown that the vascular bundles were differently distributed in a bamboo tube. In the outer layer, the vascular bundles had a variety of shapes, and were aligned parallel to each other. In the inner layers, the vascular bundles weren't aligned but uniform in shape. It was concluded that the vascular bundle sections arranged in parallel should be separated from the non-parallel sections for the maximum bamboo utilization.

  19. Robust macroscopic entanglement without complex encodings

    CERN Document Server

    Chaves, Rafael; Acín, Antonio

    2011-01-01

    One of the main challenges for the experimental manipulation and storage of macroscopic entanglement is its fragility under noise. We present a simple recipe for the systematic enhancement of the resistance of multipartite entanglement against any local noise with a privileged direction in the Bloch sphere. For the case of exact local dephasing along any given basis, and for all noise strengths, our prescription grants full robustness: even states whose entanglement decays exponentially with the number of parts are mapped to states whose entanglement is constant. In contrast to previous techniques resorting to complex logical-qubit encodings, such enhancement is attained simply by performing local unitary rotations before the noise acts. The scheme is therefore highly experimentally-friendly, as it brings no overhead of extra physical qubits to encode logical ones. In addition, we show that, apart from entanglement, the resilience of the states as resources for useful practical tasks such as metrology and non...

  20. Macroscopic Quantum Coherence in Antiferromagnetic Molecular Magnets

    Institute of Scientific and Technical Information of China (English)

    HUHui; LURong; 等

    2001-01-01

    The macroscopic quantum coherence in a biaxial antiferromagnetic molecular magnet in the presence of magnetic field acting parallel to its hard anisotropy axis is studied within the two-sublattice model.On the basis of instanton technique in the spin-coherent-state path-integral representation,both the rigorous Wentzel-Kramers-Brillouin exponent and pre-exponential factor for the ground-state tunnel splitting are obtained.We find that the quantum fluctuations around the classical paths can not only induce a new quantum phase previously reported by Chiolero and Loss (Phys.Rev.Lett.80(1998)169),but also have great influence on the intensity of the ground-state tunnel splitting.Those features clearly have no analogue in the ferromagnetic molecular magnets.We suggest that they may be the universal behaviors in all antiferromagnetic molecular magnets.The analytical results are complemented by exact diagonalization calculation.

  1. Determining the Macroscopic Properties of Relativistic Jets

    Science.gov (United States)

    Hardee, P. E.

    2004-08-01

    The resolved relativistic jets contain structures whose observed proper motions are typically assumed to indicate the jet flow speed. In addition to structures moving with the flow, various normal mode structures such as pinching or helical and elliptical twisting can be produced by ejection events or twisting perturbations to the jet flow. The normal mode structures associated with relativistic jets, as revealed by numerical simulation, theoretical calculation, and suggested by observation, move more slowly than the jet speed. The pattern speed is related to the jet speed by the sound speed in the jet and in the surrounding medium. In the event that normal mode structures are observed, and where proper motions of pattern and flow speed are available or can be estimated, it is possible to determine the sound speed in the jet and surrounding medium. Where spatial development of normal mode structures is observed, it is possible to make inferences as to the heating rate/macroscopic viscosity of the jet fluid. Ultimately it may prove possible to separate the microscopic energization of the synchrotron radiating particles from the macroscopic heating of the jet fluid. Here I present the relevant properties of useful normal mode structures and illustrate the use of this technique. Various aspects of the work presented here have involved collaboration with I. Agudo (Max-Planck, Bonn), M.A. Aloy (Max-Planck, Garching), J. Eilek (NM Tech), J.L. Gómez (U. Valencia), P. Hughes (U. Michigan), A. Lobanov (Max-Planck, Bonn), J.M. Martí (U. Valencia), & C. Walker (NRAO).

  2. Observability of relative phases of macroscopic quantum states

    CERN Document Server

    Pati, A K

    1998-01-01

    After a measurement, to observe the relative phases of macroscopically distinguishable states we have to ``undo'' a quantum measurement. We generalise an earlier model of Peres from two state to N-state quantum system undergoing measurement process and discuss the issue of observing relative phases of different branches. We derive an inequality which is satisfied by the relative phases of macroscopically distinguishable states and consequently any desired relative phases can not be observed in interference setups. The principle of macroscopic complementarity is invoked that might be at ease with the macroscopic world. We illustrate the idea of limit on phase observability in Stern-Gerlach measurements and the implications are discussed.

  3. A facile route to core-shell nanoparticulate formation of arsenic trioxide for effective solid tumor treatment

    Science.gov (United States)

    Zhang, Zongjun; Liu, Hanyu; Zhou, Hualu; Zhu, Xianglong; Zhao, Zhenghuan; Chi, Xiaoqin; Shan, Hong; Gao, Jinhao

    2016-02-01

    Arsenic trioxide has achieved great clinical success in the treatment of acute promyelocytic leukemia (APL). However, it is difficult to replicate the success in other cancers, such as solid tumors, in part because of the rapid renal clearance and dose-limiting toxicity. Nanotechnology is expected to overcome these disadvantages through altering its pharmacokinetics and concentrating the drug at the desired sites. Herein, we report a ``one-pot'' method to develop arsenic-based nanodrugs by in situ coating the as-prepared arsenic nanocomplexes with porous silica shells. This process can be easily reproduced and scaled up because no complicated synthesis and purification steps are involved. This core-shell embedding method endows nanodrugs with high loading capacity (57.9 wt%) and a prolonged pH-responsive releasing profile, which is crucial to increase the drug concentration at tumor sites and improve the drug efficacy. Based on these unique features, the nanodrugs significantly inhibit the growth of solid tumors without adverse side effects. Therefore, we anticipate that the arsenic-based nanodrugs generated by this facile synthetic route may be a powerful and alternative strategy for solid tumor therapy.Arsenic trioxide has achieved great clinical success in the treatment of acute promyelocytic leukemia (APL). However, it is difficult to replicate the success in other cancers, such as solid tumors, in part because of the rapid renal clearance and dose-limiting toxicity. Nanotechnology is expected to overcome these disadvantages through altering its pharmacokinetics and concentrating the drug at the desired sites. Herein, we report a ``one-pot'' method to develop arsenic-based nanodrugs by in situ coating the as-prepared arsenic nanocomplexes with porous silica shells. This process can be easily reproduced and scaled up because no complicated synthesis and purification steps are involved. This core-shell embedding method endows nanodrugs with high loading capacity

  4. Investigation of dissipative forces near macroscopic media

    Energy Technology Data Exchange (ETDEWEB)

    Becker, R.S.

    1982-12-01

    The interaction of classical charged particles with the fields they induce in macroscopic dielectric media is investigated. For 10- to 1000-eV electrons, the angular perturbation of the trajectory by the image potential for surface impact parameters of 50 to 100 A is shown to be of the order of 0.001 rads over a distance of 100 A. The energy loss incurred by low-energy particles due to collective excitations such as surface plasmons is shown to be observable with a transition probability of 0.01 to 0.001 (Becker, et al., 1981b). The dispersion of real surface plasmon modes in planar and cylindrical geometries is discussed and is derived for pinhole geometry described in terms of a single-sheeted hyperboloid of revolution. An experimental apparatus for the measurement of collective losses for medium-energy electrons translating close to a dielectric surface is described and discussed. Data showing such losses at electron energies of 500 to 900 eV in silver foils containing many small apertures are presented and shown to be in good agreement with classical stopping power calculations and quantum mechanical calculations carried out in the low-velocity limit. The data and calculations are compared and contrasted with earlier transmission and reflection measurements, and the course of further investigation is discussed.

  5. Searching for the nanoscopic–macroscopic boundary

    Energy Technology Data Exchange (ETDEWEB)

    Velásquez, E.A. [GICM and GES Groups, Instituto de Física-FCEN, Universidad de Antioquia UdeA, Calle 70 No. 52-21 Medellín (Colombia); Grupo de Investigación en Modelamiento y Simulación Computacional, Universidad de San Buenaventura Sec. Medellín, A.A. 5222, Medellín (Colombia); Altbir, D. [Departamento de Física, Universidad de Santiago de Chile (USACH), CEDENNA, Santiago (Chile); Mazo-Zuluaga, J. [GICM and GES Groups, Instituto de Física-FCEN, Universidad de Antioquia UdeA, Calle 70 No. 52-21 Medellín (Colombia); Duque, L.F. [GICM and GES Groups, Instituto de Física-FCEN, Universidad de Antioquia UdeA, Calle 70 No. 52-21 Medellín (Colombia); Grupo de Física Teórica, Aplicada y Didáctica, Facultad de Ciencias Exactas y Aplicadas Instituto Tecnológico Metropolitano, Medellín (Colombia); Mejía-López, J., E-mail: jmejia@puc.cl [Facultad de Física, Pontificia Universidad Católica de Chile, CEDENNA, Santiago (Chile)

    2013-12-15

    Several studies have focused on the size-dependent properties of elements, looking for a unique definition of the nanoscopic–macroscopic boundary. By using a novel approach consisting of an energy variational method combined with a quantum Heisenberg model, here we address the size at which the ordering temperature of a magnetic nanoparticle reaches its bulk value. We consider samples with sizes in the range 1–500 nm, as well as several geometries and crystalline lattices and observe that, contrarily to what is commonly argued, the nanoscopic-microscopic boundary depends on both factors: shape and crystalline structure. This suggests that the surface-to-volume ratio is not the unique parameter that defines the behavior of a nanometric sample whenever its size increases reaching the bulk dimension. Comparisons reveal very good agreement with experimental evidence with differences less than 2%. Our results have broad implications for practical issues in measurements on systems at the nanometric scale. - Highlights: • A novel quantum-Heisenberg variational energy method is implemented. • The asymptotic behavior toward the thermodynamic limit is explored. • An important dependence of the nano-bulk boundary on the geometry is found. • And also an important dependence on the crystalline lattice. • We obtain a very good agreement with experimental evidence with differences <2%.

  6. The Proell Effect: A Macroscopic Maxwell's Demon

    Science.gov (United States)

    Rauen, Kenneth M.

    2011-12-01

    Maxwell's Demon is a legitimate challenge to the Second Law of Thermodynamics when the "demon" is executed via the Proell effect. Thermal energy transfer according to the Kinetic Theory of Heat and Statistical Mechanics that takes place over distances greater than the mean free path of a gas circumvents the microscopic randomness that leads to macroscopic irreversibility. No information is required to sort the particles as no sorting occurs; the entire volume of gas undergoes the same transition. The Proell effect achieves quasi-spontaneous thermal separation without sorting by the perturbation of a heterogeneous constant volume system with displacement and regeneration. The classical analysis of the constant volume process, such as found in the Stirling Cycle, is incomplete and therefore incorrect. There are extra energy flows that classical thermo does not recognize. When a working fluid is displaced across a regenerator with a temperature gradient in a constant volume system, complimentary compression and expansion work takes place that transfers energy between the regenerator and the bulk gas volumes of the hot and cold sides of the constant volume system. Heat capacity at constant pressure applies instead of heat capacity at constant volume. The resultant increase in calculated, recyclable energy allows the Carnot Limit to be exceeded in certain cycles. Super-Carnot heat engines and heat pumps have been designed and a US patent has been awarded.

  7. Macroscopic superpositions and gravimetry with quantum magnetomechanics

    Science.gov (United States)

    Johnsson, Mattias T.; Brennen, Gavin K.; Twamley, Jason

    2016-11-01

    Precision measurements of gravity can provide tests of fundamental physics and are of broad practical interest for metrology. We propose a scheme for absolute gravimetry using a quantum magnetomechanical system consisting of a magnetically trapped superconducting resonator whose motion is controlled and measured by a nearby RF-SQUID or flux qubit. By driving the mechanical massive resonator to be in a macroscopic superposition of two different heights our we predict that our interferometry protocol could, subject to systematic errors, achieve a gravimetric sensitivity of Δg/g ~ 2.2 × 10-10 Hz-1/2, with a spatial resolution of a few nanometres. This sensitivity and spatial resolution exceeds the precision of current state of the art atom-interferometric and corner-cube gravimeters by more than an order of magnitude, and unlike classical superconducting interferometers produces an absolute rather than relative measurement of gravity. In addition, our scheme takes measurements at ~10 kHz, a region where the ambient vibrational noise spectrum is heavily suppressed compared the ~10 Hz region relevant for current cold atom gravimeters.

  8. Cloud Macroscopic Organization: Order Emerging from Randomness

    Science.gov (United States)

    Yuan, Tianle

    2011-01-01

    Clouds play a central role in many aspects of the climate system and their forms and shapes are remarkably diverse. Appropriate representation of clouds in climate models is a major challenge because cloud processes span at least eight orders of magnitude in spatial scales. Here we show that there exists order in cloud size distribution of low-level clouds, and that it follows a power-law distribution with exponent gamma close to 2. gamma is insensitive to yearly variations in environmental conditions, but has regional variations and land-ocean contrasts. More importantly, we demonstrate this self-organizing behavior of clouds emerges naturally from a complex network model with simple, physical organizing principles: random clumping and merging. We also demonstrate symmetry between clear and cloudy skies in terms of macroscopic organization because of similar fundamental underlying organizing principles. The order in the apparently complex cloud-clear field thus has its root in random local interactions. Studying cloud organization with complex network models is an attractive new approach that has wide applications in climate science. We also propose a concept of cloud statistic mechanics approach. This approach is fully complementary to deterministic models, and the two approaches provide a powerful framework to meet the challenge of representing clouds in our climate models when working in tandem.

  9. Distributivity breaking and macroscopic quantum games

    CERN Document Server

    Grib, A A; Parfionov, G N; Starkov, K A

    2005-01-01

    Examples of games between two partners with mixed strategies, calculated by the use of the probability amplitude as some vector in Hilbert space are given. The games are macroscopic, no microscopic quantum agent is supposed. The reason for the use of the quantum formalism is in breaking of the distributivity property for the lattice of yes-no questions arising due to the special rules of games. The rules of the games suppose two parts: the preparation and measurement. In the first part due to use of the quantum logical orthocomplemented non-distributive lattice the partners freely choose the wave functions as descriptions of their strategies. The second part consists of classical games described by Boolean sublattices of the initial non-Boolean lattice with same strategies which were chosen in the first part. Examples of games for spin one half are given. New Nash equilibria are found for some cases. Heisenberg uncertainty relations without the Planck constant are written for the "spin one half game".

  10. Cloud macroscopic organization: order emerging from randomness

    Directory of Open Access Journals (Sweden)

    T. Yuan

    2011-01-01

    Full Text Available Clouds play a central role in many aspects of the climate system and their forms and shapes are remarkably diverse. Appropriate representation of clouds in climate models is a major challenge because cloud processes span at least eight orders of magnitude in spatial scales. Here we show that there exists order in cloud size distribution of low-level clouds and it follows a power-law distribution with exponent γ close to 2. γ is insensitive to yearly variations in environmental conditions, but has regional variations and land-ocean contrasts. More importantly, we demonstrate this self-organizing behavior of clouds emerges naturally from a complex network model with simple, physical organizing principles: random clumping and merging. We also show clear-cloudy sky symmetry in terms of macroscopic organization because of similar fundamental underlying organizing principles. The order in the apparently complex cloud-clear field thus has its root in random simple interactions. Studying cloud organization with complex network models is an attractive new approach that has wide applications in climate science. This approach is fully complementary to deterministic models and the two approaches provide a powerful framework to meet the challenge of representing clouds in our climate models when working in tandem.

  11. Suppression of tumor development and metastasis formation in mice lacking the S100A4(mts1) gene

    DEFF Research Database (Denmark)

    Grum-Schwensen, Birgitte; Klingelhofer, Jörg; Berg, Christian Hededam

    2005-01-01

    distribution of host-derived stroma cells. Coinjection of CSML100 cells with immortalized S100A4(+/+) fibroblasts partially restored the dynamics of tumor development and the ability to form metastasis. These fibroblasts were characterized by an enhanced motility and invasiveness in comparison with S100A4...

  12. Role of vitamin D3 in modulation of ΔNp63α expression during UVB induced tumor formation in SKH-1 mice.

    Directory of Open Access Journals (Sweden)

    Natasha T Hill

    Full Text Available ΔNp63α, a proto-oncogene, is up-regulated in non-melanoma skin cancers and directly regulates the expression of both Vitamin D receptor (VDR and phosphatase and tensin homologue deleted on chromosome ten (PTEN. Since ΔNp63α has been shown to inhibit cell invasion via regulation of VDR, we wanted to determine whether dietary Vitamin D3 protected against UVB induced tumor formation in SKH-1 mice, a model for squamous cell carcinoma development. We examined whether there was a correlation between dietary Vitamin D3 and ΔNp63α, VDR or PTEN expression in vivo in SKH-1 mice chronically exposed to UVB radiation and fed chow containing increasing concentrations of dietary Vitamin D3. Although we observed differential effects of the Vitamin D3 diet on ΔNp63α and VDR expression in chronically irradiated normal mouse skin as well as UVB induced tumors, Vitamin D3 had little effect on PTEN expression in vivo. While low-grade papillomas in mice exposed to UV and fed normal chow displayed increased levels of ΔNp63α, expression of both ΔNp63α and VDR was reduced in invasive tumors. Interestingly, in mice fed high Vitamin D3 chow, elevated levels of ΔNp63α were observed in both local and invasive tumors but not in normal skin suggesting that oral supplementation with Vitamin D3 may increase the proliferative potential of skin tumors by increasing ΔNp63α levels.

  13. Design of Macroscopically Ordered Liquid Crystalline Hydrogel Columns Knitted with Nanosilver for Topical Applications.

    Science.gov (United States)

    Lali Raveendran, Reshma; Kumar Sasidharan, Nishanth; Devaki, Sudha J

    2017-04-19

    The design of liquid crystalline hydrogels knitted with silver nanoparticles in macroscopic ordering is becoming a subject of research interest due to their promising multifunctional applications in biomedical and optoelectronic applications. The present work describes the development of liquid crystalline Schiff-based hydrogel decorated with silver nanoparticles and the demonstration of its antifungal applications. Schiff base was prepared from polyglucanaldehyde and chitosan, and the former was prepared by the oxidation of amylose (polyglucopyranose) isolated from abundantly available unutilized jackfruit seed starch. Self-assembled silver columns decorated with macroscopically ordered networks were prepared in a single step of in situ condensation and a reduction/complexation process. The various noncovalent interactions among the -OH, -C═O, and -NH impart rigidity and ordering for the formation of macroscopically ordered liquid crystalline hydrogel and the Ag(I) complexation evidenced from the studies made by FT-IR spectroscopy in combination with rheology and microscopic techniques such as SEM, TEM, AFM, XRD, and PLM. The antifungal studies were screened using species of Candida by disc diffusion method. The MIC and MFC values, in vitro antifungal studies, reactive oxygen species (ROS) production, and propidium iodide (PI) uptake results suggest that the present macroscopically ordered liquid crystalline hydrogel system can be considered an excellent candidate for topical applications. All these results suggest that this design strategy can be exploited for the incorporation of biologically relevant metal nanoparticles for developing unique robust hydrogels for multifunctional applications.

  14. Evolution and distribution of macroscopic gas channels in an overburden strata

    Institute of Scientific and Technical Information of China (English)

    Liu; Hongtao; Ma; Nianjie; Ma; Wang; Ren; Guoqiang

    2012-01-01

    The evolution of gas bearing channels in the roof,and their spatial distribution,was studied.A complete consideration of gas flow changes through the stress-strain changes in the roof near a working face is made.The theoretical abutment pressure distribution using displacement monitors and borehole visual recording instruments allow a theoretical analysis.Field test research determined the conditions for formation of macroscopic gas channels.These appear along the working face roof,normally distributed to it.These results show that the coal rock stratification becomes a macroscopic gas channel boundary if its deformation is less than the lower layer,or greater than the layer above it.At the same time the stability is greater than the distance from the roof for hanging dew conditions.The working face advances and the roof gas channels experience a cycle of development.Microscopic channels dominate the initial stage then macroscopic gas channels form,develop,and close.The evolution of the macroscopic channels depends on the ratio between the distances from the new compaction area in the goaf to the initial stress area in front of the working face.The amount of daily advance of the face also affects channel development.The experimental observations in one mining area showed that the main gas channels are located about 2 and 6.2 m above the lower surface of the roof and that they have an evolution period 7 to 11 days long.

  15. Energetics of macroscopic helical domain in different tube geometries and loading

    Directory of Open Access Journals (Sweden)

    Sun Q.P.

    2010-06-01

    Full Text Available Superelastic NiTi polycrystalline shape memory alloy tubes, when subject to slow quasistatic stretching, transform to a high strain phase by the formation and growth of a macroscopic helix-shaped domain as deformation progresses. This paper performed an experimental study on the effects of the external applied nominal strain and the tube geometry (tube radius R, wall-thickness h and length L on the helical domains in isothermal stretching of the tubes. The evolution of the macroscopic domains with the applied strain in different tube geometries are quantified by in-situ optical measurement. We demonstrate that the equilibrium shape of the macroscopic helical domain and its evolution are governed by the competition between the domain front energy and the elastic-misfit bending strain energy of the tube system. The former favors a short helical domain, while the latter favors a long slim helical domain. The experimental results provided basic physical and experimental foundations for further modelling and quantification of the macroscopic domain morphology evolution in tube geometries.

  16. An Experimental Proposal for Demonstration of Macroscopic Quantum Effects

    Directory of Open Access Journals (Sweden)

    Jensen R.

    2010-10-01

    Full Text Available An experiment is proposed, whose purpose is to determine whether quantum indeterminism can be observed on a truly macroscopic scale. The experiment involves using a double-slit plate or interferometer and a macroscopic mechanical switch. The objective is to determine whether or not the switch can take on an indeterminate state.

  17. An Experimental Proposal for Demonstration of Macroscopic Quantum Effects

    Directory of Open Access Journals (Sweden)

    Jensen R.

    2010-10-01

    Full Text Available An experiment is proposed, whose purpose is to determine whether quantum indeter- minism can be observed on a truly macroscopic scale. The experiment involves using a double-slit plate or interferometer and a macroscopic mechanical switch. The objective is to determine whether or not the switch can take on an indeterminate state.

  18. Macroscopic and microscopic observations of needle insertion into gels

    NARCIS (Netherlands)

    Veen, van Youri R.J.; Jahya, Alex; Misra, Sarthak

    2012-01-01

    Needle insertion into soft tissue is one of the most common medical interventions. This study provides macroscopic and microscopic observations of needle–gel interactions. A gelatin mixture is used as a soft-tissue simulant. For the macroscopic studies, system parameters, such as insertion velocity,

  19. Hydrodynamics and convection enhanced macromolecular fluid transport in soft biological tissues: Application to solid tumor.

    Science.gov (United States)

    Dey, Bibaswan; Sekhar, G P Raja

    2016-04-21

    This work addresses a theoretical framework for transvascular exchange and extravascular transport of solute macromolecules through soft interstitial space inside a solid tumor. Most of the soft biological tissues show materialistic properties similar to deformable porous material. They exhibit mechanical behavior towards the fluid motion since the solid phase of the tumor tissue gets compressed by the drag force that is associated with the extracellular fluid flow. This paper presents a general view about the transvascular and interstitial transport of solute nutrients inside a tumor in the macroscopic level. Modified Starling׳s equation is used to describe transvascular nutrient transport. On the macroscopic level, motion of extracellular fluid within the tumor interstitium is modeled with the help of biphasic mixture theory and a spherical symmetry solution is given as a simpler case. This present model describes the average interstitial fluid pressure (IFP), extracellular fluid velocity (EFV) and flow rate of extracellular fluid, as well as the deformation of the solid phase of the tumor tissue as an immediate cause of extracellular fluid flow. When the interstitial transport is diffusion dominated, an analytical treatment of advection-diffusion-reaction equation finds the overall nutrient distribution. We propose suitable criteria for the formation of necrosis within the tumor interstitium. This study introduces some parameters that represent the nutrient supply from tumor blood vessels into the tumor extracellular space. These transport parameters compete with the reversible nutrient metabolism of the tumor cells present in the interstitium. The present study also shows that the effectiveness factor corresponding to a first order nutrient metabolism may reach beyond unity if the strength of the distributive solute source assumes positive non-zero values.

  20. Gravitational wave echoes from macroscopic quantum gravity effects

    Science.gov (United States)

    Barceló, Carlos; Carballo-Rubio, Raúl; Garay, Luis J.

    2017-05-01

    New theoretical approaches developed in the last years predict that macroscopic quantum gravity effects in black holes should lead to modifications of the gravitational wave signals expected in the framework of classical general relativity, with these modifications being characterized in certain scenarios by the existence of dampened rep-etitions of the primary signal. Here we use the fact that non-perturbative corrections to the near-horizon external geometry of black holes are necessary for these modifications to exist, in order to classify different proposals and paradigms with respect to this criterion and study in a neat and systematic way their phenomenology. Proposals that lead naturally to the existence of echoes in the late-time ringdown of gravitational wave signals from black hole mergers must share the replacement of black holes by horizonless configurations with a physical surface showing reflective properties in the relevant range of frequencies. On the other hand, proposals or paradigms that restrict quantum gravity effects on the external geometry to be perturbative, such as black hole complementarity or the closely related firewall proposal, do not display echoes. For the sake of completeness we exploit the interplay between the timescales associated with the formation of firewalls and the mechanism behind the existence of echoes in order to conclude that even unconventional distortions of the firewall concept (such as naked firewalls) do not lead to this phenomenon.

  1. Epidemiology of Brain Tumors.

    Science.gov (United States)

    McNeill, Katharine A

    2016-11-01

    Brain tumors are the commonest solid tumor in children, leading to significant cancer-related mortality. Several hereditary syndromes associated with brain tumors are nonfamilial. Ionizing radiation is a well-recognized risk factor for brain tumors. Several industrial exposures have been evaluated for a causal association with brain tumor formation but the results are inconclusive. A casual association between the common mutagens of tobacco, alcohol, or dietary factors has not yet been established. There is no clear evidence that the incidence of brain tumors has changed over time. This article presents the descriptive epidemiology of the commonest brain tumors of children and adults.

  2. Exploratory numerical experiments with a macroscopic theory of interfacial interactions

    Science.gov (United States)

    Giordano, D.; Solano-López, P.; Donoso, J. M.

    2017-09-01

    Phenomenological theories of interfacial interactions are founded on the core idea to model macroscopically the thin layer that forms between media in contact as a two-dimensional continuum (surface phase or interface) characterised by physical properties per unit area; the temporal evolution of the latter is governed by surface balance equations whose set acts as bridging channel in between the governing equations of the volume phases. These theories have targeted terrestrial applications since long time and their exploitation has inspired our research programme to build up, on the same core idea, a macroscopic theory of gas-surface interactions targeting the complex phenomenology of hypersonic reentry flows as alternative to standard methods in aerothermodynamics based on accommodation coefficients. The objective of this paper is the description of methods employed and results achieved in the exploratory study that kicked off our research programme, that is, the unsteady heat transfer between two solids in contact in planar and cylindrical configurations with and without interface. It is a simple numerical-demonstrator test case designed to facilitate quick numerical calculations but, at the same time, to bring forth already sufficiently meaningful aspects relevant to thermal protection due to the formation of the interface. The paper begins with a brief introduction on the subject matter and a review of relevant literature within an aerothermodynamics perspective. Then the case is considered in which the interface is absent. The importance of tension (force per unit area) continuity as boundary condition on the same footing of heat-flux continuity is recognised and the role of the former in governing the establishment of the temperature-difference distribution over the separation surface is explicitly shown. Evidence is given that the standard temperature-continuity boundary condition is just a particular case. Subsequently the case in which the interface is

  3. The neuronal differentiation factor NeuroD1 downregulates the neuronal repellent factor Slit2 expression and promotes cell motility and tumor formation of neuroblastoma.

    Science.gov (United States)

    Huang, Peng; Kishida, Satoshi; Cao, Dongliang; Murakami-Tonami, Yuko; Mu, Ping; Nakaguro, Masato; Koide, Naoshi; Takeuchi, Ichiro; Onishi, Akira; Kadomatsu, Kenji

    2011-04-15

    The basic helix-loop-helix transcription factor NeuroD1 has been implicated in the neurogenesis and early differentiation of pancreatic endocrine cells. However, its function in relation to cancer has been poorly examined. In this study, we found that NeuroD1 is involved in the tumorigenesis of neuroblastoma. NeuroD1 was strongly expressed in a hyperplastic region comprising neuroblasts in the celiac sympathetic ganglion of 2-week-old MYCN transgenic (Tg) mice and was consistently expressed in the subsequently generated neuroblastoma tissue. NeuroD1 knockdown by short hairpin RNA (shRNA) resulted in motility inhibition of the human neuroblastoma cell lines, and this effect was reversed by shRNA-resistant NeuroD1. The motility inhibition by NeuroD1 knockdown was associated with induction of Slit2 expression, and knockdown of Slit2 could restore cell motility. Consistent with this finding, shRNA-resistant NeuroD1 suppressed Slit2 expression. NeuroD1 directly bound to the first and second E-box of the Slit2 promoter region. Moreover, we found that the growth of tumor spheres, established from neuroblastoma cell lines in MYCN Tg mice, was suppressed by NeuroD1 suppression. The functions identified for NeuroD1 in cell motility and tumor sphere growth may suggest a link between NeuroD1 and the tumorigenesis of neuroblastoma. Indeed, tumor formation of tumor sphere-derived cells was significantly suppressed by NeuroD1 knockdown. These data are relevant to the clinical features of human neuroblastoma: high NeuroD1 expression was closely associated with poor prognosis. Our findings establish the critical role of the neuronal differentiation factor NeuroD1 in neuroblastoma as well as its functional relationship with the neuronal repellent factor Slit2.

  4. Physiological Levels of Pik3caH1047R Mutation in the Mouse Mammary Gland Results in Ductal Hyperplasia and Formation of ERα-Positive Tumors

    Science.gov (United States)

    Tikoo, Anjali; Roh, Vincent; Montgomery, Karen G.; Ivetac, Ivan; Waring, Paul; Pelzer, Rebecca; Hare, Lauren; Shackleton, Mark; Humbert, Patrick; Phillips, Wayne A.

    2012-01-01

    PIK3CA, the gene coding for the p110α subunit of phosphoinositide 3-kinase, is frequently mutated in a variety of human tumors including breast cancers. To better understand the role of mutant PIK3CA in the initiation and/or progression of breast cancer, we have generated mice with a conditional knock-in of the common activating mutation, Pik3caH1047R, into one allele of the endogenous gene in the mammary gland. These mice developed a ductal anaplasia and hyperplasia by 6 weeks of age characterized by multi-layering of the epithelial lining of the mammary ducts and expansion of the luminal progenitor (Lin−; CD29lo; CD24+; CD61+) cell population. The Pik3caH1047R expressing mice eventually develop mammary tumors with 100% penetrance but with a long latency (>12 months). This is significantly longer than has been reported for transgenic models where expression of the mutant Pik3ca is driven by an exogenous promoter. Histological analysis of the tumors formed revealed predominantly ERα-positive fibroadenomas, carcinosarcomas and sarcomas. In vitro induction of Pik3caH1047R in immortalized mammary epithelial cells also resulted in tumor formation when injected into the mammary fat pad of immunodeficient recipient mice. This novel model, which reproduces the scenario of a heterozygous somatic mutation occurring in the endogenous PIK3CA gene, will thus be a valuable tool for investigating the role of Pik3caH1047R mutation in mammary tumorigenesis both in vivo and in vitro. PMID:22666336

  5. Adipose-Derived Stem Cells Enhance Cancer Stem Cell Property and Tumor Formation Capacity in Lewis Lung Carcinoma Cells Through an Interleukin-6 Paracrine Circuit.

    Science.gov (United States)

    Lu, Jui-Hua; Wei, Hong-Jian; Peng, Bou-Yue; Chou, Hsin-Hua; Chen, Wei-Hong; Liu, Hen-Yu; Deng, Win-Ping

    2016-12-01

    Adipose-derived stem cells (ADSCs) are multipotent cells that have attracted much recent attention and emerged as therapeutic approaches in several medical fields. Although current knowledge of the biological impacts of ADSCs in cancer research is greatly improved, the underlying effects of ADSCs in tumor development remain controversial and cause the safety concerns in clinical utilization. Hence, we isolated primary ADSCs from the abdominal fat of mice and conducted interaction of ADSCs with Lewis lung carcinoma cells in culture and in mice to investigate the impacts of ADSCs on tumor development. Cytokine array and neutralizing antibody were further utilized to identify the key regulator and downstream signaling pathway. In this study, we demonstrated that ADSCs enhance the malignant characteristics of LLC1 cells, including cell growth ability and especially cancer stem cell property. ADSCs were then identified to promote tumor formation and growth in mice. We further determined that ADSC interaction with LLC1 cells stimulates increased secretion of interleukin-6 mainly from ADSCs, which then act in a paracrine manner on LLC1 cells to enhance their malignant characteristics. Interleukin-6 was also identified to regulate genes related to cell proliferation and cancer stem cell, as well as to activate JAK2/STAT3, a predominant interleukin-6-activated pathway, in LLC1 cells. Collectively, we demonstrated that ADSCs play a pro-malignant role in tumor development of Lewis lung carcinoma cells by particularly promoting cancer stem cell property through interleukin-6 paracrine circuit, which is important for safety considerations regarding the clinical application of ADSCs.

  6. Physiological levels of Pik3ca(H1047R) mutation in the mouse mammary gland results in ductal hyperplasia and formation of ERα-positive tumors.

    Science.gov (United States)

    Tikoo, Anjali; Roh, Vincent; Montgomery, Karen G; Ivetac, Ivan; Waring, Paul; Pelzer, Rebecca; Hare, Lauren; Shackleton, Mark; Humbert, Patrick; Phillips, Wayne A

    2012-01-01

    PIK3CA, the gene coding for the p110α subunit of phosphoinositide 3-kinase, is frequently mutated in a variety of human tumors including breast cancers. To better understand the role of mutant PIK3CA in the initiation and/or progression of breast cancer, we have generated mice with a conditional knock-in of the common activating mutation, Pik3ca(H1047R), into one allele of the endogenous gene in the mammary gland. These mice developed a ductal anaplasia and hyperplasia by 6 weeks of age characterized by multi-layering of the epithelial lining of the mammary ducts and expansion of the luminal progenitor (Lin(-); CD29(lo); CD24(+); CD61(+)) cell population. The Pik3ca(H1047R) expressing mice eventually develop mammary tumors with 100% penetrance but with a long latency (>12 months). This is significantly longer than has been reported for transgenic models where expression of the mutant Pik3ca is driven by an exogenous promoter. Histological analysis of the tumors formed revealed predominantly ERα-positive fibroadenomas, carcinosarcomas and sarcomas. In vitro induction of Pik3ca(H1047R) in immortalized mammary epithelial cells also resulted in tumor formation when injected into the mammary fat pad of immunodeficient recipient mice. This novel model, which reproduces the scenario of a heterozygous somatic mutation occurring in the endogenous PIK3CA gene, will thus be a valuable tool for investigating the role of Pik3ca(H1047R) mutation in mammary tumorigenesis both in vivo and in vitro.

  7. Experimental demonstration of macroscopic quantum coherence in Gaussian states

    DEFF Research Database (Denmark)

    Marquardt, C.; Andersen, Ulrik Lund; Leuchs, G.

    2007-01-01

    We witness experimentally the presence of macroscopic coherence in Gaussian quantum states using a recently proposed criterion [E. G. Cavalcanti and M. D. Reid, Phys. Rev. Lett. 97 170405 (2006)]. The macroscopic coherence stems from interference between macroscopically distinct states in phase...... space, and we prove experimentally that a coherent state contains these features with a distance in phase space of 0.51 +/- 0.02 shot noise units. This is surprising because coherent states are generally considered being at the border between classical and quantum states, not yet displaying any...

  8. Tumor promoters cause a rapid and reversible inhibition of the formation and maintenance of electrical cell coupling in culture.

    OpenAIRE

    ENOMOTO, T; Sasaki, Y.; Y Shiba; Kanno, Y.; Yamasaki, H

    1981-01-01

    The effect of tumor promoters on electrical coupling between human FL cells was investigated with a microelectrode technique. When a low concentration (100 ng/ml) of 12-O-tetradecanoylphorbol 13-acetate (TPA) was added to culture medium, only 6% of the cells showed electrical coupling after 5 hr, whereas in control medium more than 90% of the cells were coupled. In the presence of TPA, cell coupling remained suppressed for at least another 19 hr. When TPA was washed out from the culture mediu...

  9. Influence of AQP1 on cell adhesion, migration, and tumor sphere formation in malignant pleural mesothelioma is substratum- and histological-type dependent.

    Science.gov (United States)

    Jagirdar, Rajesh M; Apostolidou, Eleni; Molyvdas, Paschalis Adam; Gourgoulianis, Konstantinos I; Hatzoglou, Chrissi; Zarogiannis, Sotirios G

    2016-03-15

    Malignant pleural mesothelioma (MPM) is an aggressive cancer. MPM cells express aquaporin-1 (AQP1) that in other cancers has been shown to participate in the tumor metastasis processes. However, in MPM patients AQP1 overexpression is an independent prognostic factor favoring survival. In this study we aimed at evaluating the role of AQP1 in cell adhesion, migration, and tumor sphere formation in nonmalignant mesothelial cells (MeT-5A) and in epithelioid (M14K) and sarcomatoid (ZL34) MPM cell lines. We used fibronectin (FN) or homologous cell-derived extracellular martrix (ECM) substratum to investigate the role of AQP1 in these experimental phenotypes, inhibiting AQP1 by 10(-5) M mercury chloride (MC). Deposited ECM during cell culture exhibited significant concentration differences among cell types. ZL34 cell adhesion was significantly higher than MeT-5A or M14K cells on FN and ECM. MeT-5A and M14K cell adhesion on FN was sensitive to AQP1 inhibition, whereas AQP1 inhibition on ECM was limited to M14K cells. Wound healing in ZL34 cells was significantly higher than MeT-5A and M14K cells on FN and ECM. AQP1 inhibition significantly lowered cell migration in ZL34 cells on FN and ECM. Sphere formation was not dependent on FN or ECM in the media. AQP1 inhibition in FN media reduced sphere formation in M14K cells, whereas, in ECM, all three cell types were sensitive to AQP1 inhibition.

  10. Downregulation of HDAC9 inhibits cell proliferation and tumor formation by inducing cell cycle arrest in retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yiting; Wu, Dan; Xia, Fengjie; Xian, Hongyu; Zhu, Xinyue [Medical School of Nanjing University, Department of Ophthalmology, Jinling Hospital, Nanjing, 210002 (China); Cui, Hongjuan, E-mail: hcui@swu.edu.cn [State Key Laboratory of Silkworm Genome Biology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, 400716 (China); Huang, Zhenping, E-mail: huangzhenping19633@163.com [Medical School of Nanjing University, Department of Ophthalmology, Jinling Hospital, Nanjing, 210002 (China)

    2016-04-29

    Histone deacetylase 9 (HDAC9) is a member of class II HDACs, which regulates a wide variety of normal and abnormal physiological functions. Recently, HDAC9 has been found to be overexpressed in some types of human cancers. However, the role of HDAC9 in retinoblastoma remains unclear. In this study, we found that HDAC9 was commonly expressed in retinoblastoma tissues and HDAC9 was overexpressed in prognostically poor retinoblastoma patients. Through knocking down HDAC9 in Y79 and WERI-Rb-1 cells, the expression level of HDAC9 was found to be positively related to cell proliferation in vitro. Further investigation indicated that knockdown HDAC9 could significantly induce cell cycle arrest at G1 phase in retinoblastoma cells. Western blot assay showed downregulation of HDAC9 could significantly decrease cyclin E2 and CDK2 expression. Lastly, xenograft study in nude mice showed that downregulation of HDAC9 inhibited tumor growth and development in vivo. Therefore, our results suggest that HDAC9 could serve as a novel potential therapeutic target in the treatment of retinoblastoma. - Highlights: • High expression of HDAC9 correlates with poor patient prognosis. • Downregulation of HDAC9 inhibits cell proliferation in retinoblastoma cells. • Downregulation of HDAC9 induces cell cycle arrest at G1 phase in retinoblastoma cells. • Downregulation of HDAC9 suppresses tumor growth in nude mice.

  11. Scaffold-integrated microchips for end-to-end in vitro tumor cell attachment and xenograft formation.

    Science.gov (United States)

    Lee, Jungwoo; Kohl, Nathaniel; Shanbhang, Sachin; Parekkadan, Biju

    2015-12-01

    Microfluidic technologies have substantially advanced cancer research by enabling the isolation of rare circulating tumor cells (CTCs) for diagnostic and prognostic purposes. The characterization of isolated CTCs has been limited due to the difficulty in recovering and growing isolated cells with high fidelity. Here, we present a strategy that uses a 3D scaffold, integrated into a microfludic device, as a transferable substrate that can be readily isolated after device operation for serial use in vivo as a transplanted tissue bed. Hydrogel scaffolds were incorporated into a PDMS fluidic chamber prior to bonding and were rehydrated in the chamber after fluid contact. The hydrogel matrix completely filled the fluid chamber, significantly increasing the surface area to volume ratio, and could be directly visualized under a microscope. Computational modeling defined different flow and pressure regimes that guided the conditions used to operate the chip. As a proof of concept using a model cell line, we confirmed human prostate tumor cell attachment in the microfluidic scaffold chip, retrieval of the scaffold en masse, and serial implantation of the scaffold to a mouse model with preserved xenograft development. With further improvement in capture efficiency, this approach can offer an end-to-end platform for the continuous study of isolated cancer cells from a biological fluid to a xenograft in mice.

  12. Macroscopic description of complex adaptive networks co-evolving with dynamic node states

    CERN Document Server

    Wiedermann, Marc; Heitzig, Jobst; Lucht, Wolfgang; Kurths, Jürgen

    2015-01-01

    In many real-world complex systems, the time-evolution of the network's structure and the dynamic state of its nodes are closely entangled. Here, we study opinion formation and imitation on an adaptive complex network which is dependent on the individual dynamic state of each node and vice versa to model the co-evolution of renewable resources with the dynamics of harvesting agents on a social network. The adaptive voter model is coupled to a set of identical logistic growth models and we show that in such systems, the rate of interactions between nodes as well as the adaptive rewiring probability play a crucial role for the sustainability of the system's equilibrium state. We derive a macroscopic description of the system which provides a general framework to model and quantify the influence of single node dynamics on the macroscopic state of the network and is applicable to many fields of study, such as epidemic spreading or social modeling.

  13. Micro-macroscopic coupling in the cellular automaton model of solidification

    Directory of Open Access Journals (Sweden)

    Vinicius Bertolazzi Biscuola

    2010-12-01

    Full Text Available A cellular automaton (CA model to predict the formation of grain macrostructure during solidification has been implemented and the coupling between the microscopic and the macroscopic submodels has been investigated. The microscopic submodel simulates the nucleation and growth of grains, whereas the macroscopic solves the heat conduction equation. The directional solidification of an Al-7 wt. (% Si alloy was simulated, enabling the calculation of the temperature and solid fraction profiles. The calculated temperature was used to obtain the solid fraction profile by an application of Scheil equation. This solid fraction disagrees with that calculated in the micro-macro coupling of the model, although this coupling is completely based on Scheil equation. Careful examination of the discrepancies shows that it is a result of the undercoolings for nucleation and growth of grains and also of the interpolations of enthalpy change and temperature from the finite volume mesh to the CA cell mesh.

  14. Virtual 3D tumor marking-exact intraoperative coordinate mapping improve post-operative radiotherapy

    Directory of Open Access Journals (Sweden)

    Essig Harald

    2011-11-01

    Full Text Available Abstract The quality of the interdisciplinary interface in oncological treatment between surgery, pathology and radiotherapy is mainly dependent on reliable anatomical three-dimensional (3D allocation of specimen and their context sensitive interpretation which defines further treatment protocols. Computer-assisted preoperative planning (CAPP allows for outlining macroscopical tumor size and margins. A new technique facilitates the 3D virtual marking and mapping of frozen sections and resection margins or important surgical intraoperative information. These data could be stored in DICOM format (Digital Imaging and Communication in Medicine in terms of augmented reality and transferred to communicate patient's specific tumor information (invasion to vessels and nerves, non-resectable tumor to oncologists, radiotherapists and pathologists.

  15. Terahertz Science and Technology of Macroscopically Aligned Carbon Nanotube Films

    Science.gov (United States)

    Kono, Junichiro

    One of the outstanding challenges in nanotechnology is how to assemble individual nano-objects into macroscopic architectures while preserving their extraordinary properties. For example, the one-dimensional character of electrons in individual carbon nanotubes leads to extremely anisotropic transport, optical, and magnetic phenomena, but their macroscopic manifestations have been limited. Here, we describe methods for preparing macroscopic films, sheets, and fibers of highly aligned carbon nanotubes and their applications to basic and applied terahertz studies. Sufficiently thick films act as ideal terahertz polarizers, and appropriately doped films operate as polarization-sensitive, flexible, powerless, and ultra-broadband detectors. Together with recently developed chirality enrichment methods, these developments will ultimately allow us to study dynamic conductivities of interacting one-dimensional electrons in macroscopic single crystals of single-chirality single-wall carbon nanotubes.

  16. Accumulation of small protein molecules in a macroscopic complex coacervate

    NARCIS (Netherlands)

    Lindhoud, S.; Claessens, M.M.A.E.

    2016-01-01

    To obtain insight into the accumulation of proteins into macroscopic complex coacervate phases, the lysozyme concentration in complex coacervates containing the cationic polyelectrolyte poly-(N,N dimethylaminoethyl methacrylate) and the anionic polyelectrolyte polyacrylic acid was investigated as a

  17. Macroscopic cumulative fatigue damage of material under nonsymmetrical cycle

    Institute of Scientific and Technical Information of China (English)

    盖秉政

    2002-01-01

    Hashin's macroscopic theory of fatigue damage is further discussed and a new method has been proposed for prediction of cumulative fatigue damage of material and its lifetime under nonsymmetrical cyclic loading.

  18. Large Deviations for the Macroscopic Motion of an Interface

    Science.gov (United States)

    Birmpa, P.; Dirr, N.; Tsagkarogiannis, D.

    2017-03-01

    We study the most probable way an interface moves on a macroscopic scale from an initial to a final position within a fixed time in the context of large deviations for a stochastic microscopic lattice system of Ising spins with Kac interaction evolving in time according to Glauber (non-conservative) dynamics. Such interfaces separate two stable phases of a ferromagnetic system and in the macroscopic scale are represented by sharp transitions. We derive quantitative estimates for the upper and the lower bound of the cost functional that penalizes all possible deviations and obtain explicit error terms which are valid also in the macroscopic scale. Furthermore, using the result of a companion paper about the minimizers of this cost functional for the macroscopic motion of the interface in a fixed time, we prove that the probability of such events can concentrate on nucleations should the transition happen fast enough.

  19. Quantum fluctuations, gauge freedom and mesoscopic/macroscopic stability

    Energy Technology Data Exchange (ETDEWEB)

    Del Giudice, E [Istituto Nazionale di Fisica Nucleare, Via Celoria 16, I-20133 Milan (Italy); Vitiello, G [Dipartimento di Matematica e Informatica, Universita di Salerno and Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Salerno, 84100 Salerno (Italy)

    2007-11-15

    We study how the mesoscopic/macroscopic stability of coherent extended domains is generated out of the phase locking between gauge field and matter field. The role of the radiative gauge field in sustaining the coherent regime is discussed.

  20. New Tests of Macroscopic Local Realism using Continuous Variable Measurements

    CERN Document Server

    Reid, M D

    2001-01-01

    We show that quantum mechanics predicts an Einstein-Podolsky-Rosen paradox (EPR), and also a contradiction with local hidden variable theories, for photon number measurements which have limited resolving power, to the point of imposing an uncertainty in the photon number result which is macroscopic in absolute terms. We show how this can be interpreted as a failure of a new, very strong premise, called macroscopic local realism. We link this premise to the Schrodinger-cat paradox. Our proposed experiments ensure all fields incident on each measurement apparatus are macroscopic. We show that an alternative measurement scheme corresponds to balanced homodyne detection of quadrature phase amplitudes. The implication is that where either EPR correlations or failure of local realism is predicted for continuous variable (quadrature phase amplitude) measurements, one can perform a modified experiment which would lead to conclusions about the much stronger premise of macroscopic local realism.

  1. Tumor Necrosis Factor Receptor-associated Factor 6 (TRAF6) Associates with Huntingtin Protein and Promotes Its Atypical Ubiquitination to Enhance Aggregate Formation*

    Science.gov (United States)

    Zucchelli, Silvia; Marcuzzi, Federica; Codrich, Marta; Agostoni, Elena; Vilotti, Sandra; Biagioli, Marta; Pinto, Milena; Carnemolla, Alisia; Santoro, Claudio; Gustincich, Stefano; Persichetti, Francesca

    2011-01-01

    Huntington disease (HD) is a neurodegenerative disorder caused by an expansion of polyglutamines in the first exon of huntingtin (HTT), which confers aggregation-promoting properties to amino-terminal fragments of the protein (N-HTT). Mutant N-HTT aggregates are enriched for ubiquitin and contain ubiquitin E3 ligases, thus suggesting a role for ubiquitination in aggregate formation. Here, we report that tumor necrosis factor receptor-associated factor 6 (TRAF6) binds to WT and polyQ-expanded N-HTT in vitro as well as to endogenous full-length proteins in mouse and human brain in vivo. Endogenous TRAF6 is recruited to cellular inclusions formed by mutant N-HTT. Transient overexpression of TRAF6 promotes WT and mutant N-HTT atypical ubiquitination with Lys6, Lys27, and Lys29 linkage formation. Both interaction and ubiquitination seem to be independent from polyQ length. In cultured cells, TRAF6 enhances mutant N-HTT aggregate formation, whereas it has no effect on WT N-HTT protein localization. Mutant N-HTT inclusions are enriched for ubiquitin staining only when TRAF6 and Lys6, Lys27, and Lys29 ubiquitin mutants are expressed. Finally, we show that TRAF6 is up-regulated in post-mortem brains from HD patients where it is found in the insoluble fraction. These results suggest that TRAF6 atypical ubiquitination warrants investigation in HD pathogenesis. PMID:21454471

  2. Tumor necrosis factor receptor-associated factor 6 (TRAF6) associates with huntingtin protein and promotes its atypical ubiquitination to enhance aggregate formation.

    Science.gov (United States)

    Zucchelli, Silvia; Marcuzzi, Federica; Codrich, Marta; Agostoni, Elena; Vilotti, Sandra; Biagioli, Marta; Pinto, Milena; Carnemolla, Alisia; Santoro, Claudio; Gustincich, Stefano; Persichetti, Francesca

    2011-07-15

    Huntington disease (HD) is a neurodegenerative disorder caused by an expansion of polyglutamines in the first exon of huntingtin (HTT), which confers aggregation-promoting properties to amino-terminal fragments of the protein (N-HTT). Mutant N-HTT aggregates are enriched for ubiquitin and contain ubiquitin E3 ligases, thus suggesting a role for ubiquitination in aggregate formation. Here, we report that tumor necrosis factor receptor-associated factor 6 (TRAF6) binds to WT and polyQ-expanded N-HTT in vitro as well as to endogenous full-length proteins in mouse and human brain in vivo. Endogenous TRAF6 is recruited to cellular inclusions formed by mutant N-HTT. Transient overexpression of TRAF6 promotes WT and mutant N-HTT atypical ubiquitination with Lys(6), Lys(27), and Lys(29) linkage formation. Both interaction and ubiquitination seem to be independent from polyQ length. In cultured cells, TRAF6 enhances mutant N-HTT aggregate formation, whereas it has no effect on WT N-HTT protein localization. Mutant N-HTT inclusions are enriched for ubiquitin staining only when TRAF6 and Lys(6), Lys(27), and Lys(29) ubiquitin mutants are expressed. Finally, we show that TRAF6 is up-regulated in post-mortem brains from HD patients where it is found in the insoluble fraction. These results suggest that TRAF6 atypical ubiquitination warrants investigation in HD pathogenesis.

  3. Tumor Growth Suppression Induced by Biomimetic Silk Fibroin Hydrogels

    Science.gov (United States)

    Yan, Le-Ping; Silva-Correia, Joana; Ribeiro, Viviana P.; Miranda-Gonçalves, Vera; Correia, Cristina; da Silva Morais, Alain; Sousa, Rui A.; Reis, Rui M.; Oliveira, Ana L.; Oliveira, Joaquim M.; Reis, Rui L.

    2016-08-01

    Protein-based hydrogels with distinct conformations which enable encapsulation or differentiation of cells are of great interest in 3D cancer research models. Conformational changes may cause macroscopic shifts in the hydrogels, allowing for its use as biosensors and drug carriers. In depth knowledge on how 3D conformational changes in proteins may affect cell fate and tumor formation is required. Thus, this study reports an enzymatically crosslinked silk fibroin (SF) hydrogel system that can undergo intrinsic conformation changes from random coil to β-sheet conformation. In random coil status, the SF hydrogels are transparent, elastic, and present ionic strength and pH stimuli-responses. The random coil hydrogels become β-sheet conformation after 10 days in vitro incubation and 14 days in vivo subcutaneous implantation in rat. When encapsulated with ATDC-5 cells, the random coil SF hydrogel promotes cell survival up to 7 days, whereas the subsequent β-sheet transition induces cell apoptosis in vitro. HeLa cells are further incorporated in SF hydrogels and the constructs are investigated in vitro and in an in vivo chick chorioallantoic membrane model for tumor formation. In vivo, Angiogenesis and tumor formation are suppressed in SF hydrogels. Therefore, these hydrogels provide new insights for cancer research and uses of biomaterials.

  4. A comparison of macroscopic models describing the collective response of sedimenting rod-like particles in shear flows

    KAUST Repository

    Helzel, Christiane

    2016-07-22

    We consider a kinetic model, which describes the sedimentation of rod-like particles in dilute suspensions under the influence of gravity, presented in Helzel and Tzavaras (submitted for publication). Here we restrict our considerations to shear flow and consider a simplified situation, where the particle orientation is restricted to the plane spanned by the direction of shear and the direction of gravity. For this simplified kinetic model we carry out a linear stability analysis and we derive two different nonlinear macroscopic models which describe the formation of clusters of higher particle density. One of these macroscopic models is based on a diffusive scaling, the other one is based on a so-called quasi-dynamic approximation. Numerical computations, which compare the predictions of the macroscopic models with the kinetic model, complete our presentation.

  5. Unified Microscopic-Macroscopic Monte Carlo Simulations of Complex Organic Molecule Chemistry in Cold Cores

    CERN Document Server

    Chang, Qiang

    2016-01-01

    The recent discovery of methyl formate and dimethyl ether in the gas phase of cold cores with temperatures as cold as 10 K challenges our previous astrochemical models concerning the formation of complex organic molecules. The strong correlation between the abundances and distributions of methyl formate and dimethyl ether further shows that current astrochemical models may be missing important chemical processes in cold astronomical sources. We investigate a scenario in which complex organic molecules and the methoxy radical can be formed on dust grains via a so-called "chain reaction" mechanism, in a similar manner to CO$_2$. A unified gas-grain microscopic-macroscopic Monte Carlo approach with both normal and interstitial sites for icy grain mantles is used to perform the chemical simulations. Reactive desorption with varying degrees of efficiency is included to enhance the non-thermal desorption of species formed on cold dust grains. In addition, varying degrees of efficiency for the surface formation of m...

  6. Data on in vivo selection of SK-OV-3 Luc ovarian cancer cells and intraperitoneal tumor formation with low inoculation numbers

    Directory of Open Access Journals (Sweden)

    Elly De Vlieghere

    2016-03-01

    Full Text Available This data paper contains information about the in vivo model for peritoneal implants used in the paper “Tumor-environment biomimetics delay peritoneal metastasis formation by deceiving and redirecting disseminated cancer cells” (De Vlieghere et al., 2015 [1]. A double in vivo selection of SK-OV-3 Luc human ovarian cancer cell line was used to create SK-OV-3 Luc IP1 and SK-OV-3 Luc IP2 cell lines. This data paper shows functional activities of the three cell lines in vitro and in vivo. Phase-contrast images show the morphology of these cells, metabolic and luciferase activity has been determined. Survival data of mice peritoneally injected with SK-OV-3 Luc or SK-OV-3 Luc IP2 is available with H&E histology of the peritoneal implants. Tumor growth curves and bioluminescent images of mice inoculated with a different number of SK-OV-3 Luc IP2 cells are also included.

  7. The relationship between leptin and malignant tumor formation%瘦素与恶性肿瘤形成的关系

    Institute of Scientific and Technical Information of China (English)

    效小莉; 濮德敏

    2010-01-01

    Leptin as a polypeptide has a wide range of biologic effects, which can regulate appetite and energy metabolism common with leptin receptor. Recent studies found that leptin was related with tumor formation and development, which contribute to tumor progression by increasing angiogenesis, stimulates cell proliferation, adhesion and invasion through multiple channels.%瘦素作为一种多肽激素,具有广泛的生物学效应,其主要功能是与下丘脑瘦素受体(OBR)结合,调节食欲和能量代谢.近年研究发现,瘦素对肿瘤的形成和发展具有重要的调节作用.肿瘤细胞增生、黏着、侵袭及癌组织新生血管形成是肿瘤发生、发展的基本过程.瘦素通过多条途径参与对该过程中许多细胞及细胞因子调节的作用,影响癌灶微环境的免疫功能,促使肿瘤细胞增生、浸润和新生血管的形成,因而与肿瘤关系密切.就近年的相关研究进展进行综述.

  8. Plant stanols induce intestinal tumor formation by up-regulating Wnt and EGFR signaling in Apc Min mice.

    Science.gov (United States)

    Marttinen, Maija; Päivärinta, Essi; Storvik, Markus; Huikko, Laura; Luoma-Halkola, Heli; Piironen, Vieno; Pajari, Anne-Maria; Mutanen, Marja

    2013-01-01

    The rate of APC mutations in the intestine increases in middle-age. At the same period of life, plant sterol and stanol enriched functional foods are introduced to diet to lower blood cholesterol. This study examined the effect of plant stanol enriched diet on intestinal adenoma formation in the Apc(Min) mouse. Apc(Min) mice were fed 0.8% plant stanol diet or control diet for nine weeks. Cholesterol, plant sterols and plant stanols were analyzed from the caecum content and the intestinal mucosa. Levels of β-catenin, cyclin D1, epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase 1/2 (ERK1/2) were measured from the intestinal mucosa by Western blotting. Gene expression was determined from the intestinal mucosa using Affymetrix and the data were analyzed for enriched categories and pathways. Plant stanols induced adenoma formation in the small intestine, however, the adenoma size was not affected. We saw increased levels of nuclear β-catenin, phosphorylated β-catenin (Ser675 and Ser552), nuclear cyclin D1, total and phosphorylated EGFR and phosphorylated ERK1/2 in the intestinal mucosa after plant stanol feeding. The Affymetrix data demonstrate that several enzymes of cholesterol synthesis pathway were up-regulated, although the cholesterol level in the intestinal mucosa was not altered. We show that plant stanols induce adenoma formation by activating Wnt and EGFR signaling. EGFR signaling seems to have promoted β-catenin phosphorylation and its translocation into the nucleus, where the expression of cyclin D1 was increased. Up-regulated cholesterol synthesis may partly explain the increased EGFR signaling in the plant stanol-fed mice.

  9. Macroscopic motion of sheath-connected blobs in magnetic fields with arbitrary topology

    Science.gov (United States)

    Stepanenko, A. A.; Lee, W.; Krasheninnikov, S. I.

    2017-01-01

    In this study, macroscopic motion of sheath-connected blobs in magnetic fields, having arbitrary topology of the field lines and unfrozen in plasma, is analyzed within the electrostatic limit. Two distinct cases of magnetic configurations, with small and large curvature of the field lines, are considered and the criterion to discern them is deduced. For magnetic configurations with small curvature of the field lines, it is demonstrated that asymmetry of plasma distribution at the blob ends can drive macroscopic motion of a filament due to formation of unequal sheath potentials and establishing the effective Boltzmann potential. For a specific case of magnetic fields with small curvature of the field lines and identical metrics at the sheaths, we show that macroscopic motion of a plasma filament is determined by an effective electrostatic potential, which remains constant in time. For magnetic configurations with large curvature of the field lines, it is shown that motion of sufficiently large blobs is governed by integral distribution of plasma and magnetic field parameters along the field lines leading to blob adjusting its shape and position to the lead of the magnetic field lines in the course of its motion, whereas propagation of small and medium sized blobs can be represented as mutually independent motion of filament transverse cross-sections across the magnetic field lines. The qualitative conclusions on regularities of filament motion are supplied with numerical simulations of blob dynamics in two cases of tokamak-like magnetic fields with sheared and non-sheared field lines.

  10. Wet-spinning assembly of continuous, neat, and macroscopic graphene fibers

    Science.gov (United States)

    Cong, Huai-Ping; Ren, Xiao-Chen; Wang, Ping; Yu, Shu-Hong

    2012-01-01

    Graphene is now the most attractive carbon-based material. Integration of 2D graphene sheets into macroscopic architectures such as fibers illuminates the direction to translate the excellent properties of individual graphene into advanced hierarchical ensembles for promising applications in new graphene-based nanodevices. However, the lack of effective, low-cost and convenient assembly strategy has blocked its further development. Herein, we demonstrate that neat and macroscopic graphene fibers with high mechanical strength and electrical conductivity can be fluidly spun from the common graphene oxide (GO) suspensions in large scale followed with chemical reduction. The curliness-fold formation mechanism of GO fiber has been proposed. This wet-spinning technique presented here facilitates the multifunctionalization of macroscopic graphene-based fibers with various organic or inorganic components by an easy-handle in situ or post-synthesis approach, which builds the solid foundation to access a new family of advanced composite materials for the next practical applications. PMID:22937222

  11. Inhibition of PRL-2·CNNM3 Protein Complex Formation Decreases Breast Cancer Proliferation and Tumor Growth.

    Science.gov (United States)

    Kostantin, Elie; Hardy, Serge; Valinsky, William C; Kompatscher, Andreas; de Baaij, Jeroen H F; Zolotarov, Yevgen; Landry, Melissa; Uetani, Noriko; Martínez-Cruz, Luis Alfonso; Hoenderop, Joost G J; Shrier, Alvin; Tremblay, Michel L

    2016-05-13

    The oncogenic phosphatase of regenerating liver 2 (PRL-2) has been shown to regulate intracellular magnesium levels by forming a complex through an extended amino acid loop present in the Bateman module of the CNNM3 magnesium transporter. Here we identified highly conserved residues located on this amino acid loop critical for the binding with PRL-2. A single point mutation (D426A) of one of those critical amino acids was found to completely disrupt PRL-2·human Cyclin M 3 (CNNM3) complex formation. Whole-cell voltage clamping revealed that expression of CNNM3 influenced the surface current, whereas overexpression of the binding mutant had no effect, indicating that the binding of PRL-2 to CNNM3 is important for the activity of the complex. Interestingly, overexpression of the CNNM3 D426A-binding mutant in cancer cells decreased their ability to proliferate under magnesium-deprived situations and under anchorage-independent growth conditions, demonstrating a PRL-2·CNNM3 complex-dependent oncogenic advantage in a more stringent environment. We further confirmed the importance of this complex in vivo using an orthotopic xenograft breast cancer model. Finally, because molecular modeling showed that the Asp-426 side chain in CNNM3 buries into the catalytic cavity of PRL-2, we showed that a PRL inhibitor could abrogate complex formation, resulting in a decrease in proliferation of human breast cancer cells. In summary, we provide evidence that this fundamental regulatory aspect of PRL-2 in cancer cells could potentially lead to broadly applicable and innovative therapeutic avenues.

  12. Effect of diameter of nanoparticles and capture cross-section library on macroscopic dose enhancement in boron neutron capture therapy

    Science.gov (United States)

    Farhood, Bagher

    2014-01-01

    Purpose The aim of this study is evaluation of the effect of diameter of 10B nanoparticles and various neutron capture cross-section libraries on macroscopic dose enhancement in boron neutron capture therapy (BNCT). Material and methods MCNPX Monte Carlo code was used for simulation of a 252Cf source, a soft tissue phantom and a tumor containing 10B nanoparticles. Using 252Cf as a neutron source, macroscopic dose enhancement factor (MDEF) and total dose rate in tumor in the presence of 100, 200, and 500 ppm of 10B nanoparticles with 25 nm, 50 nm, and 100 nm diameters were calculated. Additionally, the effect of ENDF, JEFF, JENDL, and CENDL neutron capture cross-section libraries on MDEF was evaluated. Results There is not a linear relationship between the average MDEF value and nanoparticles’ diameter but the average MDEF grows with increased concentration of 10B nanoparticles. There is an increasing trend for average MDEF with the tumor distance. The average MDEF values were obtained the same for various neutron capture cross-section libraries. The maximum and minimum doses that effect on the total dose in tumor were neutron and secondary photon doses, respectively. Furthermore, the boron capture related dose component reduced in some extent with increase of diameter of 10B nanoparticles. Conclusions Based on the results of this study, it can be concluded that from physical point of view, various nanoparticle diameters have no dominant effect on average MDEF value in tumor. Furthermore, it is concluded that various neutron capture cross-section libraries are resulted to the same macroscopic dose enhancements. However, it is predicted that taking into account the biological effects for various nanoparticle diameters will result in different dose enhancements. PMID:25834582

  13. Dimerization of VirD2 binding protein is essential for Agrobacterium induced tumor formation in plants.

    Directory of Open Access Journals (Sweden)

    Abhilash Padavannil

    2014-03-01

    Full Text Available The Type IV Secretion System (T4SS is the only bacterial secretion system known to translocate both DNA and protein substrates. The VirB/D4 system from Agrobacterium tumefaciens is a typical T4SS. It facilitates the bacteria to translocate the VirD2-T-DNA complex to the host cell cytoplasm. In addition to protein-DNA complexes, the VirB/D4 system is also involved in the translocation of several effector proteins, including VirE2, VirE3 and VirF into the host cell cytoplasm. These effector proteins aid in the proper integration of the translocated DNA into the host genome. The VirD2-binding protein (VBP is a key cytoplasmic protein that recruits the VirD2-T-DNA complex to the VirD4-coupling protein (VirD4 CP of the VirB/D4 T4SS apparatus. Here, we report the crystal structure and associated functional studies of the C-terminal domain of VBP. This domain mainly consists of α-helices, and the two monomers of the asymmetric unit form a tight dimer. The structural analysis of this domain confirms the presence of a HEPN (higher eukaryotes and prokaryotes nucleotide-binding fold. Biophysical studies show that VBP is a dimer in solution and that the HEPN domain is the dimerization domain. Based on structural and mutagenesis analyses, we show that substitution of key residues at the interface disrupts the dimerization of both the HEPN domain and full-length VBP. In addition, pull-down analyses show that only dimeric VBP can interact with VirD2 and VirD4 CP. Finally, we show that only Agrobacterium harboring dimeric full-length VBP can induce tumors in plants. This study sheds light on the structural basis of the substrate recruiting function of VBP in the T4SS pathway of A. tumefaciens and in other pathogenic bacteria employing similar systems.

  14. Macroscopic states induced in superconducting media by a transport current under flux creep

    Science.gov (United States)

    Romanovskii, V. R.

    2016-08-01

    The physical features of the formation of macroscopic states of superconducting composites consisting of a superconductor and a coating under flux creep are discussed. It is demonstrated that there exist characteristic electric field strengths depending on the properties of the superconductor, cooling conditions, and characteristics of the stabilizing coating, which affect the intensity of the E-I characteristics of the superconducting composites. Analysis shows that the measurements of the critical properties of superconductors can be accompanied by a nonuniform electric field distribution over the composite cross section and high stable superheating of the superconductor, which do not lead to superconductivity breaking.

  15. Macroscopic assembly by optical control of zmol-level DNA hybridization

    Science.gov (United States)

    Iida, Takuya; Nishimura, Yushi; Tamura, Mamoru; Nishida, Keisuke; Ito, Syoji; Tokonami, Shiho

    2017-04-01

    Remote acceleration of a molecular recognition will open an avenue for the control of various biological functions. Here, we have developed a new principle for the rapid macroscopic assembly based on the light-induced molecular recognition via nanoparticles. Remarkably, as an application of this principle, we have demonstrated the submillimetre network formation triggered by light-induced hybridization of zmol-level DNA within a few minutes. This finding will be used for the rapid and highly sensitive genetic screening without fluorescent labeling.

  16. Wnt inhibition is dysregulated in gliomas and its re-establishment inhibits proliferation and tumor sphere formation.

    Science.gov (United States)

    Kierulf-Vieira, Kirsten Strømme; Sandberg, Cecilie J; Grieg, Zanina; Günther, Clara-Cecilie; Langmoen, Iver A; Vik-Mo, Einar O

    2016-01-01

    Evidence indicates that the growth of glioblastoma (GBM), the most common and malignant primary brain cancer, is driven by glioma stem cells (GSCs) resistant to current treatment. As Wnt-signaling is pivotal in stem cell maintenance, we wanted to explore its role in GSCs with the objective of finding distinct signaling mechanisms that could serve as potential therapeutic targets. We compared gene expression in GSCs (n=9) and neural stem cells from the adult human brain (ahNSC; n=3) to identify dysregulated genes in the Wnt signaling pathway. This identified a six-gene Wnt signature present in all nine primary GSC cultures, and the combined expression of three of these genes (SFRP1, SFRP4 and FZD7) reduced median survival of glioma patients from 38 to 17 months. Treatment with recombinant SFRP1 protein in primary cell cultures downregulated nuclear β-catenin and decreased in vitro proliferation and sphere formation in a dose-dependent manner. Furthermore, expressional and functional analysis of SFRP1-treated GSCs revealed that SFRP1 halts cell cycling and induces apoptosis. These observations demonstrate that Wnt signaling is dysregulated in GSC, and that inhibition of the Wnt pathway could serve as a therapeutic strategy in the treatment of GBM. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Extended Macroscopic Study of Dilute Gas Flow within a Microcavity

    Directory of Open Access Journals (Sweden)

    Mohamed Hssikou

    2016-01-01

    Full Text Available The behaviour of monatomic and dilute gas is studied in the slip and early transition regimes using the extended macroscopic theory. The gas is confined within a two-dimensional microcavity where the longitudinal sides are in the opposite motion with constant velocity ±Uw. The microcavity walls are kept at the uniform and reference temperature T0. Thus, the gas flow is transported only by the shear stress induced by the motion of upper and lower walls. From the macroscopic point of view, the regularized 13-moment equations of Grad, R13, are solved numerically. The macroscopic gas proprieties are studied for different values of the so-called Knudsen number (Kn, which gives the gas-rarefaction degree. The results are compared with those obtained using the classical continuum theory of Navier-Stokes and Fourier (NSF.

  18. Geometric aspects of Schnakenberg's network theory of macroscopic nonequilibrium observables

    Science.gov (United States)

    Polettini, M.

    2011-03-01

    Schnakenberg's network theory deals with macroscopic thermodynamical observables (forces, currents and entropy production) associated to the steady states of diffusions on generic graphs. Using results from graph theory and from the theory of discrete differential forms we recast Schnakenberg's treatment in the form of a simple discrete gauge theory, which allows to interpret macroscopic forces as the Wilson loops of a real connection. We discuss the geometric properties of transient states, showing that heat fluxes allow for a notion of duality of macroscopic observables which interchanges the role of the environment and that of the system. We discuss possible generalizations to less trivial gauge groups and the relevance for nonequilibrium fluctuation theorems. Based on work in collaboration with professor A. Maritan, University of Padua, to be published.

  19. Broadband Macroscopic Cortical Oscillations Emerge from Intrinsic Neuronal Response Failures

    Directory of Open Access Journals (Sweden)

    Amir eGoldental

    2015-10-01

    Full Text Available Broadband spontaneous macroscopic neural oscillations are rhythmic cortical firing which was extensively examined during the last century, however, their possible origination is still controversial. In this work we show how macroscopic oscillations emerge in solely excitatory random networks and without topological constraints. We experimentally and theoretically show that these oscillations stem from the counterintuitive underlying mechanism - the intrinsic stochastic neuronal response failures. These neuronal response failures, which are characterized by short-term memory, lead to cooperation among neurons, resulting in sub- or several- Hertz macroscopic oscillations which coexist with high frequency gamma oscillations. A quantitative interplay between the statistical network properties and the emerging oscillations is supported by simulations of large networks based on single-neuron in-vitro experiments and a Langevin equation describing the network dynamics. Results call for the examination of these oscillations in the presence of inhibition and external drives.

  20. Reconciling power laws in microscopic and macroscopic neural recordings

    CERN Document Server

    Pettersen, Klas H; Tetzlaff, Tom; Einevoll, Gaute T

    2013-01-01

    Power laws, characterized by quantities following 1/x^\\alpha{} distributions, are commonly reported when observing nature or society, and the question of their origin has for a long time intrigued physicists. Power laws have also been observed in neural recordings, both at the macroscopic and microscopic levels: at the macroscopic level, the power spectral density (PSD) of the electroencephalogram (EEG) has been seen to follow 1/f^\\alpha{} distributions; at the microscopic level similar power laws have been observed in single-neuron recordings of the neuronal soma potential and soma current, yet with different values of the power-law exponent \\alpha. In this theoretical study we find that these observed macroscopic and microscopic power laws may, despite the widely different spatial scales and different exponents, have the same source. By a combination of simulation on a biophysical detailed, pyramidal neuron model and analytical investigations of a simplified ball and stick neuron, we find that the transfer ...

  1. Microscopic and macroscopic infarct complicating pediatric epilepsy surgery.

    Science.gov (United States)

    Rubinger, Luc; Hazrati, Lili-Naz; Ahmed, Raheel; Rutka, James; Snead, Carter; Widjaja, Elysa

    2017-03-01

    There is some suggestion that microscopic infarct could be associated with invasive monitoring, but it is unclear if the microscopic infarct is also visible on imaging and associated with neurologic deficits. The aims of this study were to assess the rates of microscopic and macroscopic infarct and other major complications of pediatric epilepsy surgery, and to determine if these complications were higher following invasive monitoring. We reviewed the epilepsy surgery data from a tertiary pediatric center, and collected data on microscopic infarct on histology and macroscopic infarct on postoperative computed tomography (CT) or magnetic resonance imaging (MRI) done one day after surgery and major complications. Three hundred fifty-two patients underwent surgical resection and there was one death. Forty-two percent had invasive monitoring. Thirty patients (9%) had microscopic infarct. Univariable analyses showed that microscopic infarct was higher among patients with invasive monitoring relative to no invasive monitoring (20% vs. 0.5%, respectively, p microscopic infarct had transient right hemiparesis, and two with both macroscopic and microscopic infarct had unexpected persistent neurologic deficits. Thirty-two major complications (9.1%) were reported, with no difference in major complications between invasive monitoring and no invasive monitoring (10% vs. 7%, p = 0.446). In the multivariable analysis, invasive monitoring increased the odds of microscopic infarct (odds ratio [OR] 15.87, p = 0.009), but not macroscopic infarct (OR 2.6, p = 0.173) or major complications (OR 1.4, p = 0.500), after adjusting for age at surgery, sex, age at seizure onset, operative type, and operative location. Microscopic infarct was associated with invasive monitoring, and none of the patients had permanent neurologic deficits. Macroscopic infarct was not associated with invasive monitoring, and two patients with macroscopic infarct had persistent neurologic deficits. Wiley

  2. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  3. Approximating macroscopic observables in quantum spin systems with commuting matrices

    CERN Document Server

    Ogata, Yoshiko

    2011-01-01

    Macroscopic observables in a quantum spin system are given by sequences of spatial means of local elements $\\frac{1}{2n+1}\\sum_{j=-n}^n\\gamma_j(A_{i}), \\; n\\in{\\mathbb N},\\; i=1,...,m$ in a UHF algebra. One of their properties is that they commute asymptotically, as $n$ goes to infinity. It is not true that any given set of asymptotically commuting matrices can be approximated by commuting ones in the norm topology. In this paper, we show that for macroscopic observables, this is true.

  4. On the notion of a macroscopic quantum system

    CERN Document Server

    Khrenikov, A Yu

    2004-01-01

    We analyse the notion of macroscopic quantum system from the point of view of the statistical structure of quantum theory. We come to conclusion that the presence of interference of probabilities should be used the main characteristic of quantumness (in the opposition to N. Bohr who permanently emphasized the crucial role of quantum action). In the light of recent experiments with statistical ensembles of people who produced interference of probabilities for special pairs of questions (which can be considered as measurements on people) human being should be considered as a macroscopic quantum system. There is also discussed relation with experiments of A. Zeilinger on interference of probabilities for macromoleculas.

  5. Stimuli-deformable graphene materials: from nanosheet to macroscopic assembly

    Directory of Open Access Journals (Sweden)

    Fei Zhao

    2016-04-01

    Full Text Available Stimulus-induced deformation (SID of graphene-based materials has triggered rapidly increasing research interest due to the spontaneous response to external stimulations, which enables precise configurational regulation of single graphene nanosheets (GNSs through control over the environmental conditions. While the micro-strain of GNS is barely visible, the deformation of graphene-based macroscopic assemblies (GMAs is remarkable, thereby presenting significant potential for future application in smart devices. This review presents the current progress of SID of graphene in the manner of nanosheets and macroscopic assemblies in both the experimental and theoretical fronts, and summarizes recent advancements of SID of graphene for applications in smart systems.

  6. Statistical thermodynamics understanding the properties of macroscopic systems

    CERN Document Server

    Fai, Lukong Cornelius

    2012-01-01

    Basic Principles of Statistical PhysicsMicroscopic and Macroscopic Description of StatesBasic PostulatesGibbs Ergodic AssumptionGibbsian EnsemblesExperimental Basis of Statistical MechanicsDefinition of Expectation ValuesErgodic Principle and Expectation ValuesProperties of Distribution FunctionRelative Fluctuation of an Additive Macroscopic ParameterLiouville TheoremGibbs Microcanonical EnsembleMicrocanonical Distribution in Quantum MechanicsDensity MatrixDensity Matrix in Energy RepresentationEntropyThermodynamic FunctionsTemperatureAdiabatic ProcessesPressureThermodynamic IdentityLaws of Th

  7. Tumor hypoxia induces nuclear paraspeckle formation through HIF-2α dependent transcriptional activation of NEAT1 leading to cancer cell survival.

    Science.gov (United States)

    Choudhry, H; Albukhari, A; Morotti, M; Haider, S; Moralli, D; Smythies, J; Schödel, J; Green, C M; Camps, C; Buffa, F; Ratcliffe, P; Ragoussis, J; Harris, A L; Mole, D R

    2015-08-20

    Activation of cellular transcriptional responses, mediated by hypoxia-inducible factor (HIF), is common in many types of cancer, and generally confers a poor prognosis. Known to induce many hundreds of protein-coding genes, HIF has also recently been shown to be a key regulator of the non-coding transcriptional response. Here, we show that NEAT1 long non-coding RNA (lncRNA) is a direct transcriptional target of HIF in many breast cancer cell lines and in solid tumors. Unlike previously described lncRNAs, NEAT1 is regulated principally by HIF-2 rather than by HIF-1. NEAT1 is a nuclear lncRNA that is an essential structural component of paraspeckles and the hypoxic induction of NEAT1 induces paraspeckle formation in a manner that is dependent upon both NEAT1 and on HIF-2. Paraspeckles are multifunction nuclear structures that sequester transcriptionally active proteins as well as RNA transcripts that have been subjected to adenosine-to-inosine (A-to-I) editing. We show that the nuclear retention of one such transcript, F11R (also known as junctional adhesion molecule 1, JAM1), in hypoxia is dependent upon the hypoxic increase in NEAT1, thereby conferring a novel mechanism of HIF-dependent gene regulation. Induction of NEAT1 in hypoxia also leads to accelerated cellular proliferation, improved clonogenic survival and reduced apoptosis, all of which are hallmarks of increased tumorigenesis. Furthermore, in patients with breast cancer, high tumor NEAT1 expression correlates with poor survival. Taken together, these results indicate a new role for HIF transcriptional pathways in the regulation of nuclear structure and that this contributes to the pro-tumorigenic hypoxia-phenotype in breast cancer.

  8. Transforming growth factor-alpha abrogates glucocorticoid-stimulated tight junction formation and growth suppression in rat mammary epithelial tumor cells.

    Science.gov (United States)

    Buse, P; Woo, P L; Alexander, D B; Cha, H H; Reza, A; Sirota, N D; Firestone, G L

    1995-03-24

    The glucocorticoid and transforming growth factor-alpha (TGF-alpha) regulation of growth and cell-cell contact was investigated in the Con8 mammary epithelial tumor cell line derived from a 7,12-dimethylbenz(alpha)anthracene-induced rat mammary adenocarcinoma. In Con8 cell monolayers cultured on permeable filter supports, the synthetic glucocorticoid, dexamethasone, coordinately suppressed [3H]thymidine incorporation, stimulated monolayer transepithelial electrical resistance (TER), and decreased the paracellular leakage of [3H]inulin or [14C]mannitol across the monolayer. These processes dose dependently correlated with glucocorticoid receptor occupancy and function. Constitutive production of TGF-alpha in transfected cells or exogenous treatment with TGF-alpha prevented the glucocorticoid growth suppression response and disrupted tight junction formation without affecting glucocorticoid responsiveness. Treatment with hydroxyurea or araC demonstrated that de novo DNA synthesis is not a requirement for the growth factor disruption of tight junctions. Immunofluorescence analysis revealed that the ZO-1 tight junction protein is localized exclusively at the cell periphery in dexamethasone-treated cells and that TGF-alpha caused-ZO-1 to relocalize from the cell periphery back to a cytoplasmic compartment. Taken together, our results demonstrate that glucocorticoids can coordinately regulate growth inhibition and cell-cell contact of mammary tumor cells and that TGF-alpha, can override both effects of glucocorticoids. These results have uncovered a novel functional "cross-talk" between glucocorticoids and TGF-alpha which potentially regulates the proliferation and differentiation of mammary epithelial cells.

  9. Combined olaparib and oxaliplatin inhibits tumor proliferation and induces G2/M arrest and γ-H2AX foci formation in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Xu K

    2015-10-01

    Full Text Available Kaiwu Xu,1* Zhihui Chen,2* Yi Cui,1 Changjiang Qin,2 Yulong He,2 Xinming Song2 1Endoscopy Center, 2Gastrointestinal Surgery Center, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province, People’s Republic of China *These authors contributed equally to this work Background: Poly (ADP-ribose polymerase 1 (PARP1 has an important role in homologous recombination repair. The purpose of this study was to investigate the effect of PARP1 inhibitor on oxaliplatin treatment for colorectal cancer (CRC. Methods: A cell counting kit-8 assay was used to determine the sensitivity of CRC cells to olaparib and/or oxaliplatin. The gene and protein expressions of PARP1 and the gamma histone variant H2AX (γH2AX were measured by real-time quantitative polymerase chain reaction and western blotting, respectively. The γH2AX foci formation assay was used to investigate the influence of treatments on cells. Flow cytometry was used to examine the changes in cell cycle distribution. Finally, we investigated the combination of olaparib and oxaliplatin in the CRC tumor model. Results: Olaparib changed the expression of γH2AX and PARP1, and increased the sensitivity of CRC cells to oxaliplatin. The γH2AX foci assay showed that olaparib did not induce double-strand breaks (DSBs alone, but it enhanced the induction of DSBs by oxaliplatin. The flow cytometry results showed that cells exposed to combination treatment had more G2/M-phase cells than control. Additionally, tumor xenograft studies suggested that combined treatment inhibited the growth of CRC. Conclusion: CRC cells are sensitized to combined treatment with olaparib and oxaliplatin, and this could be a promising strategy for clinical chemotherapy in CRC. Keywords: olaparib, oxaliplatin, chemosensitization, colorectal cancer

  10. I. Embryonal vasculature formation recapitulated in transgenic mammary tumor spheroids implanted pseudo-orthotopicly into mouse dorsal skin fold: the organoblasts concept [v2; ref status: indexed, http://f1000r.es/1fa

    Directory of Open Access Journals (Sweden)

    Halina Witkiewicz

    2013-07-01

    Full Text Available Inadequate understanding of cancer biology is a problem. This work focused on cellular mechanisms of tumor vascularization. According to earlier studies, the tumor vasculature derives from host endothelial cells (angiogenesis or their precursors of bone marrow origin circulating in the blood (neo-vasculogenesis unlike in embryos. In this study, we observed the neo-vasculature form in multiple ways from local precursor cells. Recapitulation of primitive as well as advanced embryonal stages of vasculature formation followed co-implantation of avascular (in vitro cultured N202 breast tumor spheroids and homologous tissue grafts into mouse dorsal skin chambers. Ultrastructural and immunocytochemical analysis of tissue sections exposed the interactions between the tumor and the graft tissue stem cells. It revealed details of vasculature morphogenesis not seen before in either tumors or embryos. A gradual increase in complexity of the vascular morphogenesis at the tumor site reflected a range of steps in ontogenic evolution of the differentiating cells. Malignant- and surgical injury repair-related tissue growth prompted local cells to initiate extramedullar erythropoiesis and vascular patterning. The new findings included: interdependence between the extramedullar hematopoiesis and assembly of new vessels (both from the locally differentiating precursors; nucleo-cytoplasmic conversion (karyolysis as the mechanism of erythroblast enucleation; the role of megakaryocytes and platelets in vascular pattern formation before emergence of endothelial cells; lineage relationships between hematopoietic and endothelial cells; the role of extracellular calmyrin in tissue morphogenesis; and calmyrite, a new ultrastructural entity associated with anaerobic energy metabolism. The central role of the extramedullar erythropoiesis in the formation of new vasculature (blood and vessels emerged here as part of the tissue building process including the lymphatic system

  11. Benign and malignant mammary tumors induced by DMBA in female Wistar rats

    OpenAIRE

    Dias, M.; Cabrita, S; Sousa, E.; França, B; Patrício, J; Oliveira, CF

    1999-01-01

    This study pretends to characterize 7, 12-dimetylbenz[a]anthracene-induced benign and malignant tumors. One hundred and twenty female Wistar rats were randomly allocated to two groups: Control Group and Induction Group; IG animals were given a single dose of DMBA and killed 24 weeks after. Other tumors besides breast tumors were diagnosed, mainly tumors of the salivary glands and ovarian benign epithelial tumors. Incidence of breast disorders was about 60%. Macroscopic mammary tumors varied i...

  12. Quantum statistical derivation of the macroscopic Maxwell equations

    NARCIS (Netherlands)

    Schram, K.

    1960-01-01

    The macroscopic Maxwell equations in matter are derived on a quantum statistical basis from the microscopic equations for the field operators. Both the density operator formalism and the Wigner distribution function method are discussed. By both methods it can be proved that the quantum statistical

  13. Macroscopic and Microscopic Gradient Structures of Bamboo Culms

    Directory of Open Access Journals (Sweden)

    Suwat SUTNAUN

    2005-01-01

    Full Text Available This work studied the structure of bamboo culms which is naturally designed to retard the bending stress caused by a wind load. A macroscopic gradient structure (diameter, thickness and internodal length and a microscopic one (distribution of fiber of three sympodial bamboo species i.e. Tong bamboo (Dendrocalamus asper Backer., Pah bamboo (Gigantochloa bambos and Pak bamboo (Gigantochloa hasskarliana were examined. From the macroscopic point of view, the wind-load generated bending stress for the tapered hollow tube of bamboo was found to vary uniformly with height, especially at the middle of the culms. Furthermore, the macroscopic shape of bamboo culm is about 2-6 times stiffer in bending mode than one with a solid circular section for the same amount of wood material. Microscopically, the distribution of fiber in the radial direction linearly decreases from the outer surface to the inner surface in the same manner as that of the distribution of the bending stress in the radial direction. Distribution of fiber along the vertical length of bamboos at each height is proportional to the level of bending stress generated by the wind load. Both macroscopic and microscopic gradient structures of sympodial type bamboos were found to be less effective to retard the bending stress than those of monopodial type bamboo.

  14. Microstructure and macroscopic properties of polydisperse systems of hard spheres

    NARCIS (Netherlands)

    Ogarko, Vitaliy Anatolyevich

    2014-01-01

    This dissertation describes an investigation of systems of polydisperse smooth hard spheres. This includes the development of a fast contact detection algorithm for computer modelling, the development of macroscopic constitutive laws that are based on microscopic features such as the moments of the

  15. [Macroscopic observations on corneal epithelial wound healing in the rabbit].

    Science.gov (United States)

    Hayashi, K

    1991-02-01

    A newly-developed macroscope was applied to observe the healing process of corneal epithelial wound in vivo. After removing epithelium of the central cornea, the changes of the corneal surface were observed with the macroscope and the findings were compared with histological examinations. At 12 hours after abrasion, areas unstained with Richardson's staining (R staining) appeared. In the histological section, a single layer of regenerating epithelial cells covered the same area. At 24 and 36 hours after abrasion, the epithelial defects became smaller but surrounding epithelium was rough and showed dot-like staining with R solution. By 2 days, the epithelial defects disappeared. On macroscopic observation, the central corneal surface showed a pavement-like appearance. Histology revealed that the regenerating epithelium still consisted of one or two layers. At 3 days, dot-like stainings were present only in the center and the corneal surface appeared considerably smooth. Histology also showed that regenerating epithelium became columnar and multilayered, thereby suggesting stratification. By 7 days, the abraded corneal surface had recovered its smooth appearance. Histologic sections also demonstrated that the epithelium had regained its normal structure. Thus, using this macroscope, findings suggesting the process of epithelial migration and proliferation could be observed.

  16. The black hole information paradox and macroscopic superpositions

    CERN Document Server

    Hsu, Stephen D H

    2010-01-01

    We investigate the experimental capabilities required to test whether black holes destroy information. We show that an experiment capable of illuminating the information puzzle must necessarily be able to detect or manipulate macroscopic superpositions (i.e., Everett branches). Hence, it could also address the fundamental question of decoherence versus wavefunction collapse.

  17. A Macroscopic Analogue of the Nuclear Pairing Potential

    Science.gov (United States)

    Dunlap, Richard A.

    2013-01-01

    A macroscopic system involving permanent magnets is used as an analogue to nucleons in a nucleus to illustrate the significance of the pairing interaction. This illustrates that the view of the total nuclear energy based only on the nucleon occupancy of the energy levels can yield erroneous results and it is only when the pairing interaction is…

  18. Data requirements for traffic control on a macroscopic level

    NARCIS (Netherlands)

    Knoop, V.L.; Van Lint, J.W.C.; Hoogendoorn, S.P.

    2011-01-01

    With current techniques, traffic monitoring and control is a data intensive process. Network control on a higher level, using high level variables, can make this process less data demanding. The macroscopic fundamental diagram relates accumulation, i.e. the number of vehicles in an area, to the netw

  19. Stereodynamics: From elementary processes to macroscopic chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Toshio [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Graduate School of Science, Department of Chemistry, Osaka University, Toyonaka, 560-0043 Osaka (Japan); Che, Dock-Chil [Graduate School of Science, Department of Chemistry, Osaka University, Toyonaka, 560-0043 Osaka (Japan); Tsai, Po-Yu [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Lin, King-Chuen [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Palazzetti, Federico [Scuola Normale Superiore, Pisa (Italy); Dipartimento di Chimica Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Aquilanti, Vincenzo [Dipartimento di Chimica Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Roma (Italy); Instituto de Fisica, Universidade Federal da Bahia, Salvador (Brazil)

    2015-12-31

    This paper aims at discussing new facets on stereodynamical behaviors in chemical reactions, i.e. the effects of molecular orientation and alignment on reactive processes. Further topics on macroscopic processes involving deviations from Arrhenius behavior in the temperature dependence of chemical reactions and chirality effects in collisions are also discussed.

  20. Mesoscopic kinetic basis of macroscopic chemical thermodynamics: A mathematical theory.

    Science.gov (United States)

    Ge, Hao; Qian, Hong

    2016-11-01

    Gibbs' macroscopic chemical thermodynamics is one of the most important theories in chemistry. Generalizing it to mesoscaled nonequilibrium systems is essential to biophysics. The nonequilibrium stochastic thermodynamics of chemical reaction kinetics suggested a free energy balance equation dF^{(meso)}/dt=E_{in}-e_{p} in which the free energy input rate E_{in} and dissipation rate e_{p} are both non-negative, and E_{in}≤e_{p}. We prove that in the macroscopic limit by merely allowing the molecular numbers to be infinite, the generalized mesoscopic free energy F^{(meso)} converges to φ^{ss}, the large deviation rate function for the stationary distributions. This generalized macroscopic free energy φ^{ss} now satisfies a balance equation dφ^{ss}(x)/dt=cmf(x)-σ(x), in which x represents chemical concentration. The chemical motive force cmf(x) and entropy production rate σ(x) are both non-negative, and cmf(x)≤σ(x). The balance equation is valid generally in isothermal driven systems and is different from mechanical energy conservation and the first law; it is actually an unknown form of the second law. Consequences of the emergent thermodynamic quantities and equalities are further discussed. The emergent "law" is independent of underlying kinetic details. Our theory provides an example showing how a macroscopic law emerges from a level below.

  1. Diagnosis of bladder tumours in patients with macroscopic haematuria

    DEFF Research Database (Denmark)

    Gandrup, Karen L; Løgager, Vibeke B; Bretlau, Thomas

    2015-01-01

    OBJECTIVE: The aim of this study was to compare split-bolus computed tomography urography (CTU), magnetic resonance urography (MRU) and flexible cystoscopy in patients with macroscopic haematuria regarding the diagnosis of bladder tumours. MATERIALS AND METHODS: In this prospective study, 150...

  2. Microstructure and macroscopic properties of polydisperse systems of hard spheres

    NARCIS (Netherlands)

    Ogarko, V.

    2014-01-01

    This dissertation describes an investigation of systems of polydisperse smooth hard spheres. This includes the development of a fast contact detection algorithm for computer modelling, the development of macroscopic constitutive laws that are based on microscopic features such as the moments of the

  3. Integrating a macro emission model with a macroscopic traffic model

    NARCIS (Netherlands)

    Klunder, G.A.; Stelwagen, U.; Taale, H.

    2013-01-01

    This paper presents a macro emission module for macroscopic traffic models to be used for assessment of ITS and traffic management. It especially focuses on emission estimates for different intersection types. It provides emission values for CO, CO2, HC, NOx, and PM10. It is applied and validated fo

  4. From 1D to 3D - macroscopic nanowire aerogel monoliths.

    Science.gov (United States)

    Cheng, Wei; Rechberger, Felix; Niederberger, Markus

    2016-08-01

    Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying.

  5. Numerical solutions of a generalized theory for macroscopic capillarity

    NARCIS (Netherlands)

    Doster, F.; Zegeling, P.A.; Hilfer, R.

    2010-01-01

    A recent macroscopic theory of biphasic flow in porous media [R. Hilfer, Phys. Rev. E 73, 016307 (2006)] has proposed to treat microscopically percolating fluid regions differently from microscopically nonpercolating regions. Even in one dimension the theory reduces to an analytically intractable se

  6. The fundamental diagram : a macroscopic traffic flow model.

    NARCIS (Netherlands)

    Botma, H.

    1976-01-01

    In models of traffic flow, the interactions between vehicles are of prime interest, and are based on characteristics of the drivers, road and vehicles. The fundamental diagram is a representation of a relationship on a macroscopic level in the steady state between the quantity of traffic and a chara

  7. Charge accumulation in DC cables: a macroscopic approach

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson; Crichton, George C; Pedersen, Aage

    1994-01-01

    The accumulation of space charge in solid dielectrics is examined from the macroscopic point of view using electromagnetic field theory. For practical dielectrics, it is shown that the occurrence of such charges is an inherent consequence of a non-uniform conductivity. The influence of both tempe...

  8. Mesoscopic kinetic basis of macroscopic chemical thermodynamics: A mathematical theory

    Science.gov (United States)

    Ge, Hao; Qian, Hong

    2016-11-01

    Gibbs' macroscopic chemical thermodynamics is one of the most important theories in chemistry. Generalizing it to mesoscaled nonequilibrium systems is essential to biophysics. The nonequilibrium stochastic thermodynamics of chemical reaction kinetics suggested a free energy balance equation d F(meso)/d t =Ein-ep in which the free energy input rate Ein and dissipation rate ep are both non-negative, and Ein≤ep . We prove that in the macroscopic limit by merely allowing the molecular numbers to be infinite, the generalized mesoscopic free energy F(meso) converges to φss, the large deviation rate function for the stationary distributions. This generalized macroscopic free energy φss now satisfies a balance equation d φss(x ) /d t =cmf(x ) -σ (x ) , in which x represents chemical concentration. The chemical motive force cmf(x ) and entropy production rate σ (x ) are both non-negative, and cmf(x )≤σ (x ) . The balance equation is valid generally in isothermal driven systems and is different from mechanical energy conservation and the first law; it is actually an unknown form of the second law. Consequences of the emergent thermodynamic quantities and equalities are further discussed. The emergent "law" is independent of underlying kinetic details. Our theory provides an example showing how a macroscopic law emerges from a level below.

  9. 微小RNA调控肿瘤细胞耐药机制形成的研究进展%Research progress of microRNA regulating the formation of tumor cell resistance mechanism

    Institute of Scientific and Technical Information of China (English)

    孙财

    2015-01-01

    At present,the poor prognosis of conventional chemotherapy for most malignant tumors is an important problem for clinical work,but the tumor cell resistance is one of the important reasons for the failure of chemotherapy.The existence of tumor stem cell resistance ean cause tumor cells to reduce the sensitivity of most chemical drugs after a positive chemotherapy,the recurrence and metastasis of tumor can ultimately endanger the patient's life.The formation mechanism of drug resistance of tumor cells is complex.And there are many signal molecules and signal transduction pathways related with the formation mechanism of drug resistance,but the concrete mechanism is not yet fully clarified.MicroRNA (miRNA) and the formation of tumor drug resistance are highly correlated according to relevant researches.MiRNA can targetedly regulate drug resistance mechanism and plays a very important role in reducing drug resistance of tumor cells.This article intends to review the research advances of the formation mechanism of miRNA resistant tumor cells.%目前,多数恶性肿瘤常规化疗效果差、预后不良,是困扰临床工作的重要难题,而肿瘤细胞耐药性的产生是导致化疗失败的重要原因之一.经过积极化疗后,残存肿瘤干细胞耐药性的存在,可导致肿瘤细胞对多数化学药物敏感性降低,引起肿瘤复发、转移,最终危及患者生命.肿瘤细胞耐药性的形成机制较为复杂,涉及的信号分子及信号通路相对较多,其具体机制尚未完全阐明.根据目前相关研究,微小RNA(miRNA)与肿瘤耐药性的形成高度相关.miRNA通过对耐药机制进行靶向调节,对减少肿瘤细胞耐药性形成起着非常重要的作用.笔者拟就目前miRNA调控肿瘤细胞耐药机制形成的研究进展进行综述.

  10. Macroscopic quantum phenomena from the large N perspective

    Science.gov (United States)

    Chou, C. H.; Hu, B. L.; Subaşi, Y.

    2011-07-01

    Macroscopic quantum phenomena (MQP) is a relatively new research venue, with exciting ongoing experiments and bright prospects, yet with surprisingly little theoretical activity. What makes MQP intellectually stimulating is because it is counterpoised against the traditional view that macroscopic means classical. This simplistic and hitherto rarely challenged view need be scrutinized anew, perhaps with much of the conventional wisdoms repealed. In this series of papers we report on a systematic investigation into some key foundational issues of MQP, with the hope of constructing a viable theoretical framework for this new endeavour. The three major themes discussed in these three essays are the large N expansion, the correlation hierarchy and quantum entanglement for systems of 'large' sizes, with many components or degrees of freedom. In this paper we use different theories in a variety of contexts to examine the conditions or criteria whereby a macroscopic quantum system may take on classical attributes, and, more interestingly, that it keeps some of its quantum features. The theories we consider here are, the O(N) quantum mechanical model, semiclassical stochastic gravity and gauge / string theories; the contexts include that of a 'quantum roll' in inflationary cosmology, entropy generation in quantum Vlasov equation for plasmas, the leading order and next-to-leading order large N behaviour, and hydrodynamic / thermodynamic limits. The criteria for classicality in our consideration include the use of uncertainty relations, the correlation between classical canonical variables, randomization of quantum phase, environment-induced decoherence, decoherent history of hydrodynamic variables, etc. All this exercise is to ask only one simple question: Is it really so surprising that quantum features can appear in macroscopic objects? By examining different representative systems where detailed theoretical analysis has been carried out, we find that there is no a priori

  11. The origins of macroscopic quantum coherence in high temperature superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Philip, E-mail: ph.turner@napier.ac.uk [Edinburgh Napier University, 10 Colinton Road, Edinburgh EH10 5DT (United Kingdom); Nottale, Laurent, E-mail: laurent.nottale@obspm.fr [CNRS, LUTH, Observatoire de Paris-Meudon, 5 Place Janssen, 92190 Meudon (France)

    2015-08-15

    Highlights: • We propose a new theoretical approach to superconductivity in p-type cuprates. • Electron pairing mechanisms in the superconducting and pseudogap phases are proposed. • A scale free network of dopants is key to macroscopic quantum coherence. - Abstract: A new, theoretical approach to macroscopic quantum coherence and superconductivity in the p-type (hole doped) cuprates is proposed. The theory includes mechanisms to account for e-pair coupling in the superconducting and pseudogap phases and their inter relations observed in these materials. Electron pair coupling in the superconducting phase is facilitated by local quantum potentials created by static dopants in a mechanism which explains experimentally observed optimal doping levels and the associated peak in critical temperature. By contrast, evidence suggests that electrons contributing to the pseudogap are predominantly coupled by fractal spin waves (fractons) induced by the fractal arrangement of dopants. On another level, the theory offers new insights into the emergence of a macroscopic quantum potential generated by a fractal distribution of dopants. This, in turn, leads to the emergence of coherent, macroscopic spin waves and a second associated macroscopic quantum potential, possibly supported by charge order. These quantum potentials play two key roles. The first involves the transition of an expected diffusive process (normally associated with Anderson localization) in fractal networks, into e-pair coherence. The second involves the facilitation of tunnelling between localized e-pairs. These combined effects lead to the merger of the super conducting and pseudo gap phases into a single coherent condensate at optimal doping. The underlying theory relating to the diffusion to quantum transition is supported by Coherent Random Lasing, which can be explained using an analogous approach. As a final step, an experimental program is outlined to validate the theory and suggests a new

  12. Macroscopic quantum phenomena from the large N perspective

    Energy Technology Data Exchange (ETDEWEB)

    Chou, C H [department of Physics, National Cheng Kung University, Tainan, Taiwan 701 (China) and National Center for Theoretical Sciences (South), Tainan, Taiwan 701 (China); Hu, B L; Subasi, Y, E-mail: hubeilok@gmail.com [Joint Quantum Institute and Maryland Center for Fundamental Physics, University of Maryland, College Park, Maryland 20742 (United States)

    2011-07-08

    Macroscopic quantum phenomena (MQP) is a relatively new research venue, with exciting ongoing experiments and bright prospects, yet with surprisingly little theoretical activity. What makes MQP intellectually stimulating is because it is counterpoised against the traditional view that macroscopic means classical. This simplistic and hitherto rarely challenged view need be scrutinized anew, perhaps with much of the conventional wisdoms repealed. In this series of papers we report on a systematic investigation into some key foundational issues of MQP, with the hope of constructing a viable theoretical framework for this new endeavour. The three major themes discussed in these three essays are the large N expansion, the correlation hierarchy and quantum entanglement for systems of 'large' sizes, with many components or degrees of freedom. In this paper we use different theories in a variety of contexts to examine the conditions or criteria whereby a macroscopic quantum system may take on classical attributes, and, more interestingly, that it keeps some of its quantum features. The theories we consider here are, the O(N) quantum mechanical model, semiclassical stochastic gravity and gauge / string theories; the contexts include that of a 'quantum roll' in inflationary cosmology, entropy generation in quantum Vlasov equation for plasmas, the leading order and next-to-leading order large N behaviour, and hydrodynamic / thermodynamic limits. The criteria for classicality in our consideration include the use of uncertainty relations, the correlation between classical canonical variables, randomization of quantum phase, environment-induced decoherence, decoherent history of hydrodynamic variables, etc. All this exercise is to ask only one simple question: Is it really so surprising that quantum features can appear in macroscopic objects? By examining different representative systems where detailed theoretical analysis has been carried out, we find that

  13. Macroscopic description of complex adaptive networks coevolving with dynamic node states

    Science.gov (United States)

    Wiedermann, Marc; Donges, Jonathan F.; Heitzig, Jobst; Lucht, Wolfgang; Kurths, Jürgen

    2015-05-01

    In many real-world complex systems, the time evolution of the network's structure and the dynamic state of its nodes are closely entangled. Here we study opinion formation and imitation on an adaptive complex network which is dependent on the individual dynamic state of each node and vice versa to model the coevolution of renewable resources with the dynamics of harvesting agents on a social network. The adaptive voter model is coupled to a set of identical logistic growth models and we mainly find that, in such systems, the rate of interactions between nodes as well as the adaptive rewiring probability are crucial parameters for controlling the sustainability of the system's equilibrium state. We derive a macroscopic description of the system in terms of ordinary differential equations which provides a general framework to model and quantify the influence of single node dynamics on the macroscopic state of the network. The thus obtained framework is applicable to many fields of study, such as epidemic spreading, opinion formation, or socioecological modeling.

  14. Generation of free radicals from organic hydroperoxide tumor promoters in isolated mouse keratinocytes. Formation of alkyl and alkoxyl radicals from tert-butyl hydroperoxide and cumene hydroperoxide.

    Science.gov (United States)

    Taffe, B G; Takahashi, N; Kensler, T W; Mason, R P

    1987-09-05

    The organic hydroperoxides tert-butyl hydroperoxide and cumene hydroperoxide are tumor promoters in the skin of SENCAR mice, and this activity is presumed to be mediated through the activation of the hydroperoxides to free radical species. In this study we have assessed the generation of free radicals from organic hydroperoxides in the target cell (the murine basal keratinocyte) using electron spin resonance. Incubation of primary isolates of keratinocytes from SENCAR mice in the presence of spin traps (5,5-dimethyl-1-pyrroline N-oxide or 2-methyl-2-nitrosopropane) and either tert-butyl hydroperoxide or cumene hydroperoxide resulted in the generation and detection of radical adducts of these spin traps. tert-Butyl alkoxyl and alkyl radical adducts of 5,5-dimethyl-1-pyrroline N-oxide were detected shortly after addition of tert-butyl hydroperoxide, whereas only alkyl radical adducts were observed with cumene hydroperoxide. Spin trapping of the alkyl radicals with 2-methyl-2-nitrosopropane led to the identification of methyl and ethyl radical adducts following both tert-butyl hydroperoxide and cumene hydroperoxide exposures. Prior heating of the cells to 100 degrees C for 30 min prevented radical formation. The radical generating capacity of subcellular fractions of these epidermal cells was examined using 5,5-dimethyl-1-pyrroline N-oxide and cumene hydroperoxide, and this activity was confined to the 105,000 X g supernatant fraction.

  15. 6-Bromoisatin Found in Muricid Mollusc Extracts Inhibits Colon Cancer Cell Proliferation and Induces Apoptosis, Preventing Early Stage Tumor Formation in a Colorectal Cancer Rodent Model

    Directory of Open Access Journals (Sweden)

    Babak Esmaeelian

    2013-12-01

    Full Text Available Muricid molluscs are a natural source of brominated isatin with anticancer activity. The aim of this study was to examine the safety and efficacy of synthetic 6-bromoisatin for reducing the risk of early stage colorectal tumor formation. The purity of 6-bromoisatin was confirmed by 1H NMR spectroscopy, then tested for in vitro and in vivo anticancer activity. A mouse model for colorectal cancer was utilized whereby colonic apoptosis and cell proliferation was measured 6 h after azoxymethane treatment by hematoxylin and immunohistochemical staining. Liver enzymes and other biochemistry parameters were measured in plasma and haematological assessment of the blood was conducted to assess potential toxic side-effects. 6-Bromoisatin inhibited proliferation of HT29 cells at IC50 223 μM (0.05 mg/mL and induced apoptosis without increasing caspase 3/7 activity. In vivo 6-bromoisatin (0.05 mg/g was found to significantly enhance the apoptotic index (p ≤ 0.001 and reduced cell proliferation (p ≤ 0.01 in the distal colon. There were no significant effects on mouse body weight, liver enzymes, biochemical factors or blood cells. However, 6-bromoisatin caused a decrease in the plasma level of potassium, suggesting a diuretic effect. In conclusion this study supports 6-bromoisatin in Muricidae extracts as a promising lead for prevention of colorectal cancer.

  16. Overexpression of the dynein light chain km23-1 in human ovarian carcinoma cells inhibits tumor formation in vivo and causes mitotic delay at prometaphase/metaphase.

    Science.gov (United States)

    Pulipati, Nageswara R; Jin, Qunyan; Liu, Xin; Sun, Baodong; Pandey, Manoj K; Huber, Jonathan P; Ding, Wei; Mulder, Kathleen M

    2011-08-01

    km23-1 is a dynein light chain that was identified as a TGFβ receptor-interacting protein. To investigate whether km23-1 controls human ovarian carcinoma cell (HOCC) growth, we established a tet-off inducible expression system in SKOV-3 cells in which the expression of km23-1 is induced upon doxycycline removal. We found that forced expression of km23-1 inhibited both anchorage-dependent and anchorage-independent growth of SKOV-3 cells. More importantly, induction of km23-1 expression substantially reduced the tumorigenicity of SKOV-3 cells in a xenograft model in vivo. Fluorescence-activated cell sorting analysis of SKOV-3 and IGROV-1 HOCCs demonstrated that the cells were accumulating at G2/M. Phospho-MEK, phospho-ERK and cyclin B1 were elevated, as was the mitotic index, suggesting that km23-1 suppresses HOCCs growth by inducing a mitotic delay. Immunofluorescence analyses demonstrated that the cells were accumulating at prometaphase/metaphase with increases in multipolar and multinucleated cells. Further, although the mitotic spindle assembly checkpoint protein BubR1 was present at the prometaphase kinetochore in Dox+/- cells, it was inappropriately retained at the metaphase kinetochore in Dox- cells. Thus, the mechanism by which high levels of km23-1 suppress ovarian carcinoma growth in vitro and inhibit ovary tumor formation in vivo appears to involve a BubR1-related mitotic delay.

  17. SIMPL enhancement of tumor necrosis factor-α dependent p65-MED1 complex formation is required for mammalian hematopoietic stem and progenitor cell function.

    Directory of Open Access Journals (Sweden)

    Weina Zhao

    Full Text Available Significant insight into the signaling pathways leading to activation of the Rel transcription factor family, collectively termed NF-κB, has been gained. Less well understood is how subsets of NF-κB-dependent genes are regulated in a signal specific manner. The SIMPL protein (signaling molecule that interacts with mouse pelle-like kinase is required for full Tumor Necrosis Factor-α (TNFα induced NF-κB activity. We show that SIMPL is required for steady-state hematopoiesis and the expression of a subset of TNFα induced genes whose products regulate hematopoietic cell activity. To gain insight into the mechanism through which SIMPL modulates gene expression we focused on the Tnf gene, an immune response regulator required for steady-state hematopoiesis. In response to TNFα SIMPL localizes to the Tnf gene promoter where it modulates the initiation of Tnf gene transcription. SIMPL binding partners identified by mass spectrometry include proteins involved in transcription and the interaction between SIMPL and MED1 was characterized in more detail. In response to TNFα, SIMPL is found in p65-MED1 complexes where SIMPL enhances p65/MED1/SIMPL complex formation. Together our results indicate that SIMPL functions as a TNFα-dependent p65 co-activator by facilitating the recruitment of MED1 to p65 containing transcriptional complexes to control the expression of a subset of TNFα-induced genes.

  18. A fortran code CVTRAN to provide cross-section file for TWODANT by using macroscopic file written by SRAC

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Tsuyoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Tsuchihashi, Keichiro

    1999-03-01

    A code CVTRAN provides the macroscopic cross-sections in the format of XSLIB file which is one of Standard interface files for a two-dimensional Sn transport code TWODANT by reading a macroscopic cross section file in the PDS format which is prepared by SRAC execution. While a two-dimensional Sn transport code TWOTRAN published by LANL is installed as a module in the SRAC code system, several functions such as alpha search, concentration search, zone thickness search and various edits are suppressed. Since the TWODANT code was released from LANL, its short running time, stable convergence and plenty of edits have attracted many users. The code CVTRAN makes the TWODANT available to the SRAC user by providing the macroscopic cross-sections on a card-image file XSLIB. The CVTRAN also provides material dependent fission spectra into a card-image format file CVLIB, together with group velocities, group boundary energies and material names. The user can feed them into the TWODANT input, if necessary, by cut-and-paste command. (author)

  19. Unified Microscopic-Macroscopic Monte Carlo Simulations of Complex Organic Molecule Chemistry in Cold Cores

    Science.gov (United States)

    Chang, Qiang; Herbst, Eric

    2016-03-01

    The recent discovery of methyl formate and dimethyl ether in the gas phase of cold cores with temperatures as cold as 10 K challenges our previous astrochemical models concerning the formation of complex organic molecules (COMs). The strong correlation between the abundances and distributions of methyl formate and dimethyl ether further shows that current astrochemical models may be missing important chemical processes in cold astronomical sources. We investigate a scenario in which COMs and the methoxy radical can be formed on dust grains via a so-called chain reaction mechanism, in a similar manner to CO2. A unified gas-grain microscopic-macroscopic Monte Carlo approach with both normal and interstitial sites for icy grain mantles is used to perform the chemical simulations. Reactive desorption with varying degrees of efficiency is included to enhance the nonthermal desorption of species formed on cold dust grains. In addition, varying degrees of efficiency for the surface formation of methoxy are also included. The observed abundances of a variety of organic molecules in cold cores can be reproduced in our models. The strong correlation between the abundances of methyl formate and dimethyl ether in cold cores can also be explained. Nondiffusive chemical reactions on dust grain surfaces may play a key role in the formation of some COMs.

  20. Wave speeds in the macroscopic extended model for ultrarelativistic gases

    Energy Technology Data Exchange (ETDEWEB)

    Borghero, F., E-mail: borghero@unica.it [Dip. Matematica e Informatica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy); Demontis, F., E-mail: fdemontis@unica.it [Dip. Matematica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); Pennisi, S., E-mail: spennisi@unica.it [Dip. Matematica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy)

    2013-11-15

    Equations determining wave speeds for a model of ultrarelativistic gases are investigated. This model is already present in literature; it deals with an arbitrary number of moments and it was proposed in the context of exact macroscopic approaches in Extended Thermodynamics. We find these results: the whole system for the determination of the wave speeds can be divided into independent subsystems which are expressed by linear combinations, through scalar coefficients, of tensors all of the same order; some wave speeds, but not all of them, are expressed by square roots of rational numbers; finally, we prove that these wave speeds for the macroscopic model are the same of those furnished by the kinetic model.

  1. From 1D to 3D - macroscopic nanowire aerogel monoliths

    Science.gov (United States)

    Cheng, Wei; Rechberger, Felix; Niederberger, Markus

    2016-07-01

    Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying.Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying. Electronic supplementary information (ESI) available: Experimental details, SEM and TEM images, and digital photographs. See DOI: 10.1039/c6nr04429h

  2. Microscopic versus macroscopic approaches to non-equilibrium systems

    Science.gov (United States)

    Derrida, Bernard

    2011-01-01

    The one-dimensional symmetric simple exclusion process (SSEP) is one of the very few exactly soluble models of non-equilibrium statistical physics. It describes a system of particles which diffuse with hard core repulsion on a one-dimensional lattice in contact with two reservoirs of particles at unequal densities. The goal of this paper is to review the two main approaches which lead to the exact expression of the large deviation functional of the density of the SSEP in its steady state: a microscopic approach (based on the matrix product ansatz and an additivity property) and a macroscopic approach (based on the macroscopic fluctuation theory of Bertini, De Sole, Gabrielli, Jona-Lasinio and Landim).

  3. Wave speeds in the macroscopic extended model for ultrarelativistic gases

    Energy Technology Data Exchange (ETDEWEB)

    Borghero, F., E-mail: borghero@unica.it [Dip. Matematica e Informatica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy); Demontis, F., E-mail: fdemontis@unica.it [Dip. Matematica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); Pennisi, S., E-mail: spennisi@unica.it [Dip. Matematica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy)

    2013-11-15

    Equations determining wave speeds for a model of ultrarelativistic gases are investigated. This model is already present in literature; it deals with an arbitrary number of moments and it was proposed in the context of exact macroscopic approaches in Extended Thermodynamics. We find these results: the whole system for the determination of the wave speeds can be divided into independent subsystems which are expressed by linear combinations, through scalar coefficients, of tensors all of the same order; some wave speeds, but not all of them, are expressed by square roots of rational numbers; finally, we prove that these wave speeds for the macroscopic model are the same of those furnished by the kinetic model.

  4. Applying quantum mechanics to macroscopic and mesoscopic systems

    CERN Document Server

    T., N Poveda

    2012-01-01

    There exists a paradigm in which Quantum Mechanics is an exclusively developed theory to explain phenomena on a microscopic scale. As the Planck's constant is extremely small, $h\\sim10^{-34}{J.s}$, and as in the relation of de Broglie the wavelength is inversely proportional to the momentum; for a mesoscopic or macroscopic object the Broglie wavelength is very small, and consequently the undulatory behavior of this object is undetectable. In this paper we show that with a particle oscillating around its classical trajectory, the action is an integer multiple of a quantum of action, $S = nh_{o}$. The quantum of action, $h_{o}$, which plays a role equivalent to Planck's constant, is a free parameter that must be determined and depends on the physical system considered. For a mesoscopic and macroscopic system: $h_{o}\\gg h$, this allows us to describe these systems with the formalism of quantum mechanics.

  5. Analysis and Enhancements of a Prolific Macroscopic Model of Epilepsy

    Directory of Open Access Journals (Sweden)

    Christopher Fietkiewicz

    2016-01-01

    Full Text Available Macroscopic models of epilepsy can deliver surprisingly realistic EEG simulations. In the present study, a prolific series of models is evaluated with regard to theoretical and computational concerns, and enhancements are developed. Specifically, we analyze three aspects of the models: (1 Using dynamical systems analysis, we demonstrate and explain the presence of direct current potentials in the simulated EEG that were previously undocumented. (2 We explain how the system was not ideally formulated for numerical integration of stochastic differential equations. A reformulated system is developed to support proper methodology. (3 We explain an unreported contradiction in the published model specification regarding the use of a mathematical reduction method. We then use the method to reduce the number of equations and further improve the computational efficiency. The intent of our critique is to enhance the evolution of macroscopic modeling of epilepsy and assist others who wish to explore this exciting class of models further.

  6. Indirect measurement of interfacial melting from macroscopic ice observations.

    Science.gov (United States)

    Saruya, Tomotaka; Kurita, Kei; Rempel, Alan W

    2014-06-01

    Premelted water that is adsorbed to particle surfaces and confined to capillary regions remains in the liquid state well below the bulk melting temperature and can supply the segregated growth of ice lenses. Using macroscopic measurements of ice-lens initiation position in step-freezing experiments, we infer how the nanometer-scale thicknesses of premelted films depend on temperature depression below bulk melting. The interfacial interactions between ice, liquid, and soda-lime glass particles exhibit a power-law behavior that suggests premelting in our system is dominated by short-range electrostatic forces. Using our inferred film thicknesses as inputs to a simple force-balance model with no adjustable parameters, we obtain good quantitative agreement between numerical predictions and observed ice-lens thickness. Macroscopic observations of lensing behavior have the potential as probes of premelting behavior in other systems.

  7. Optomechanical entanglement of a macroscopic oscillator by quantum feedback

    Science.gov (United States)

    Wu, E.; Li, Fengzhi; Zhang, Xuefeng; Ma, Yonghong

    2016-07-01

    We propose a scheme to generate the case of macroscopic entanglement in the optomechanical system, which consist of Fabry-Perot cavity and a mechanical oscillator by applying a homodyne-mediated quantum feedback. We explore the effect of feedback on the entanglement in vacuum and coherent state, respectively. The results show that the introduction of quantum feedback can increase the entanglement effectively between the cavity mode and the oscillator mode.

  8. Identification of Bodies Exposed to High Temperatures Based on Macroscopic...

    OpenAIRE

    Barraza Salcedo, María del Socorro; Universidad Metropolitana de Barranquilla. Barranquilla; Rebolledo Cobos, Martha Leonor; Universidad Metropolitana de Barranquilla

    2016-01-01

    ABSTRACT. Background: Forensic dentistry in cases of incineration provides scientific elements that allow the identification of bodies, by analyzing dental organs, through the isolation of DNA obtained from the pulp as an alternative to confirm the identity of the victim. When the degree of temperature is highly elevated, dental tissues are vulnerable and therefore the DNA pulp is not salvageable, wasting resources and time by lack of standards to identify macroscopic characteristics that ind...

  9. CONTRIBUTION OF MACROSCOPIC DIMENSION EFFECT TO PIEZOELFCTRICITY IN POLYVINYLIDENE FLUORIDE

    Institute of Scientific and Technical Information of China (English)

    WEN Jianxun; TAKEO FURUKAWA

    1987-01-01

    In this paper, we have studied the piezoelectricity in the poled uniaxially drawn polyvinylidene fluoride. The piezoelectric constants d31, d32, da33 and Young's moduli 1/s11 and 1/s22 have been determined as a function of the remanent polarization Pr. The piezoelectric constants of the samples show a strong in-plane anisotropy. Such an anisotropy is mostly attributable to different Poisson's ratio. It is found that the piezoelectric activity mainly arises from macroscopic dimensional change.

  10. Toward a superconducting quantum computer. Harnessing macroscopic quantum coherence.

    Science.gov (United States)

    Tsai, Jaw-Shen

    2010-01-01

    Intensive research on the construction of superconducting quantum computers has produced numerous important achievements. The quantum bit (qubit), based on the Josephson junction, is at the heart of this research. This macroscopic system has the ability to control quantum coherence. This article reviews the current state of quantum computing as well as its history, and discusses its future. Although progress has been rapid, the field remains beset with unsolved issues, and there are still many new research opportunities open to physicists and engineers.

  11. Measurement-Induced Macroscopic Superposition States in Cavity Optomechanics

    Science.gov (United States)

    Hoff, Ulrich B.; Kollath-Bönig, Johann; Neergaard-Nielsen, Jonas S.; Andersen, Ulrik L.

    2016-09-01

    A novel protocol for generating quantum superpositions of macroscopically distinct states of a bulk mechanical oscillator is proposed, compatible with existing optomechanical devices operating in the bad-cavity limit. By combining a pulsed optomechanical quantum nondemolition (QND) interaction with nonclassical optical resources and measurement-induced feedback, the need for strong single-photon coupling is avoided. We outline a three-pulse sequence of QND interactions encompassing squeezing-enhanced cooling by measurement, state preparation, and tomography.

  12. Formation of a major DNA adduct of the mitomycin metabolite 2,7-diaminomitosene in EMT6 mouse mammary tumor cells treated with mitomycin C.

    Science.gov (United States)

    Palom, Y; Belcourt, M F; Kumar, G S; Arai, H; Kasai, M; Sartorelli, A C; Rockwell, S; Tomasz, M

    1998-01-01

    Treatment of EMT6 mouse mammary tumor cells with [3H]mitomycin C (MC) results in the formation of six major DNA adducts, as described earlier using an HPLC assay of 3H-labeled products of enzymatic hydrolysis of DNA isolated from MC-treated cells. Four of these adducts were identified as monofunctional and bifunctional guanine-N2 adducts in the minor groove of DNA. In order to establish relationships between individual types of MC-DNA adducts and biological responses it is necessary to identify all of the adducts formed in cells. To this end we have now identified a predominant, previously unknown adduct formed in MC-treated EMT6 cells as a derivative not of MC, but of 2,7-diaminomitosene (2,7-DAM), the major bioreductive metabolite of MC. Rigorous proof demonstrates that it is a DNA major groove, guanine-N7 adduct of 2,7-DAM, linked at C-10 to DNA. The adduct is relatively stable at ambient temperature, but is readily depurinated upon heating. Its isolation from MC-treated cells indicates that MC is reductively metabolized to 2,7-DAM, which then undergoes further reductive activation to alkylate DNA, along with the parent MC. Low MC:DNA ratios were identified as a critical factor promoting 2,7-DAM adduct formation in an in vitro model calf thymus DNA/ MC/reductase model system, as well as in MC-treated EMT6 cells. The 2,7-DAM-guanine-N7 DNA adduct appears to be relatively noncytotoxic, as indicated by the dramatically lower cytotoxicity of 2,7-DAM in comparison with MC in EMT6 cells. Like MC, 2,7-DAM exhibited slightly greater cytotoxicity to cells treated under hypoxic as compared to aerobic conditions. However, 2,7-DAM was markedly less cytotoxic than MC under both aerobic and hypoxic conditions. Thus, metabolic reduction of MC to 2,7-DAM represents a detoxification process. The differential effects of MC-DNA and 2,7-DAM-DNA adducts support the concept that specific structural features of the DNA damage may play a critical role in the cytotoxic response to a DNA

  13. Macroscopic Quantum Phenomena from the Correlation, Coupling and Criticality Perspectives

    Science.gov (United States)

    Chou, C. H.; Hu, B. L.; Subaşi, Y.

    2011-12-01

    In this sequel paper we explore how macroscopic quantum phenomena can be measured or understood from the behavior of quantum correlations which exist in a quantum system of many particles or components and how the interaction strengths change with energy or scale, under ordinary situations and when the system is near its critical point. We use the nPI (master) effective action related to the Boltzmann-BBGKY / Schwinger-Dyson hierarchy of equations as a tool for systemizing the contributions of higher order correlation functions to the dynamics of lower order correlation functions. Together with the large N expansion discussed in our first paper [1] we explore 1) the conditions whereby an H-theorem is obtained, which can be viewed as a signifier of the emergence of macroscopic behavior in the system. We give two more examples from past work: 2) the nonequilibrium dynamics of N atoms in an optical lattice under the large Script N (field components), 2PI and second order perturbative expansions, illustrating how N and Script N enter in these three aspects of quantum correlations, coherence and coupling strength. 3) the behavior of an interacting quantum system near its critical point, the effects of quantum and thermal fluctuations and the conditions under which the system manifests infrared dimensional reduction. We also discuss how the effective field theory concept bears on macroscopic quantum phenomena: the running of the coupling parameters with energy or scale imparts a dynamical-dependent and an interaction-sensitive definition of 'macroscopia'.

  14. Stochastic and Macroscopic Thermodynamics of Strongly Coupled Systems

    Science.gov (United States)

    Jarzynski, Christopher

    2017-01-01

    We develop a thermodynamic framework that describes a classical system of interest S that is strongly coupled to its thermal environment E . Within this framework, seven key thermodynamic quantities—internal energy, entropy, volume, enthalpy, Gibbs free energy, heat, and work—are defined microscopically. These quantities obey thermodynamic relations including both the first and second law, and they satisfy nonequilibrium fluctuation theorems. We additionally impose a macroscopic consistency condition: When S is large, the quantities defined within our framework scale up to their macroscopic counterparts. By satisfying this condition, we demonstrate that a unifying framework can be developed, which encompasses both stochastic thermodynamics at one end, and macroscopic thermodynamics at the other. A central element in our approach is a thermodynamic definition of the volume of the system of interest, which converges to the usual geometric definition when S is large. We also sketch an alternative framework that satisfies the same consistency conditions. The dynamics of the system and environment are modeled using Hamilton's equations in the full phase space.

  15. Macroscopic quantum oscillator based on a flux qubit

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mandip, E-mail: mandip@iisermohali.ac.in

    2015-09-25

    In this paper a macroscopic quantum oscillator is proposed, which consists of a flux-qubit in the form of a cantilever. The net magnetic flux threading through the flux-qubit and the mechanical degrees of freedom of the cantilever are naturally coupled. The coupling between the cantilever and the magnetic flux is controlled through an external magnetic field. The ground state of the flux-qubit-cantilever turns out to be an entangled quantum state, where the cantilever deflection and the magnetic flux are the entangled degrees of freedom. A variant, which is a special case of the flux-qubit-cantilever without a Josephson junction, is also discussed. - Highlights: • In this paper a flux-qubit-cantilever is proposed. • Coupling can be varied by an external magnetic field. • Ground state is a macroscopic entangled quantum state. • Ground state of the superconducting-loop-oscillator is a macroscopic quantum superposition. • Proposed scheme is based on a generalized quantum approach.

  16. Macroscopic description of the limb muscles of Tupinambis merianae

    Directory of Open Access Journals (Sweden)

    Juliana Barbosa Casals

    2012-03-01

    Full Text Available Tegu lizard (Tupinambis merianae belongs to the Teiidae family. It is distributed throughout the Americas, with many species, including Brazilian ones. They are from the Tupinambis genus, the largest representatives of the Teiidae family. For this study three animals (run over coming from donation were used. The dissected lizards were fixed in 10%, formaldehyde, and the macroscopic analysis was carried out in a detailed and photo documented way, keeping the selected structures “in situ”. This paper had as its main aim contributing to the macroscopic description of the chest myology, as well as the thoracic and pelvic limbs of the lizard T. merianae. The results obtained from this research were compared to authors who have studied animals from the same Reptilia class. Thus, we conclude that our macroscopic results are similar to those already described by the researchers Hildebrand (1995, Moro and Abdala (2004 and Abdala and Diogo (2010. We should highlight that the knowledge on anatomy has importance and applications to various areas within Biology, contributing in a substantial way to the areas of human health and technology.

  17. Mesoscopic Kinetic Basis of Macroscopic Chemical Thermodynamics: A Mathematical Theory

    CERN Document Server

    Ge, Hao

    2016-01-01

    From a mathematical model that describes a complex chemical kinetic system of $N$ species and $M$ elementrary reactions in a rapidly stirred vessel of size $V$ as a Markov process, we show that a macroscopic chemical thermodynamics emerges as $V\\rightarrow\\infty$. The theory is applicable to linear and nonlinear reactions, closed systems reaching chemical equilibrium, or open, driven systems approaching to nonequilibrium steady states. A generalized mesoscopic free energy gives rise to a macroscopic chemical energy function $\\varphi^{ss}(\\vx)$ where $\\vx=(x_1,\\cdots,x_N)$ are the concentrations of the $N$ chemical species. The macroscopic chemical dynamics $\\vx(t)$ satisfies two emergent laws: (1) $(\\rd/\\rd t)\\varphi^{ss}[\\vx(t)]\\le 0$, and (2)$(\\rd/\\rd t)\\varphi^{ss}[\\vx(t)]=\\text{cmf}(\\vx)-\\sigma(\\vx)$ where entropy production rate $\\sigma\\ge 0$ represents the sink for the chemical energy, and chemical motive force $\\text{cmf}\\ge 0$ is non-zero if the system is driven under a sustained nonequilibrium chemos...

  18. Noise-driven interfaces and their macroscopic representation

    Science.gov (United States)

    Dentz, Marco; Neuweiler, Insa; Méheust, Yves; Tartakovsky, Daniel M.

    2016-11-01

    We study the macroscopic representation of noise-driven interfaces in stochastic interface growth models in (1 +1 ) dimensions. The interface is characterized macroscopically by saturation, which represents the fluctuating sharp interface by a smoothly varying phase field with values between 0 and 1. We determine the one-point interface height statistics for the Edwards-Wilkinson (EW) and Kadar-Paris-Zhang (KPZ) models in order to determine explicit deterministic equations for the phase saturation for each of them. While we obtain exact results for the EW model, we develop a Gaussian closure approximation for the KPZ model. We identify an interface compression term, which is related to mass transfer perpendicular to the growth direction, and a diffusion term that tends to increase the interface width. The interface compression rate depends on the mesoscopic mass transfer process along the interface and in this sense provides a relation between meso- and macroscopic interface dynamics. These results shed light on the relation between mesoscale and macroscale interface models, and provide a systematic framework for the upscaling of stochastic interface dynamics.

  19. Heterogeneity of tumor vasculature and antiangiogenic intervention: insights from MR angiography and DCE-MRI.

    Directory of Open Access Journals (Sweden)

    Wenlian Zhu

    Full Text Available PURPOSE: Solid tumor vasculature is highly heterogeneous, which presents challenges to antiangiogenic intervention as well as the evaluation of its therapeutic efficacy. The aim of this study is to evaluate the spatial tumor vascular changes due to bevacizumab/paclitaxel therapy using a combination approach of MR angiography and DCE-MRI method. EXPERIMENTAL DESIGN: Tumor vasculature of MCF-7 breast tumor mouse xenografts was studied by a combination of MR angiography and DCE-MRI with albumin-Gd-DTPA. Tumor macroscopic vasculature was extracted from the early enhanced images. Tumor microvascular parameters were obtained from the pharmacokinetic modeling of the DCE-MRI data. A spatial analysis of the microvascular parameters based on the macroscopic vasculature was used to evaluate the changes of the heterogeneous vasculature induced by a 12 day bevacizumab/paclitaxel treatment in mice bearing MCF-7 breast tumor. RESULTS: Macroscopic vessels that feed the tumors were not affected by the bevacizumab/paclitaxel combination therapy. A higher portion of the tumors was within close proximity of these macroscopic vessels after the treatment, concomitant with tumor growth retardation. There was a significant decrease in microvascular permeability and vascular volume in the tumor regions near these vessels. CONCLUSION: Bevacizumab/paclitaxel combination therapy did not block the blood supply to the MCF-7 breast tumor. Such finding is consistent with the modest survival benefits of adding bevacizumab to current treatment regimens for some types of cancers.

  20. Micromechanical study of macroscopic friction and dissipation in idealised granular materials: the effect of interparticle friction

    NARCIS (Netherlands)

    Kruyt, N.P.; Rothenburg, L.; Gutkowski, Witold; Kowalewski, Tomasz A.

    2004-01-01

    Using Discrete Element Method (DEM) simulations with varying interparticle friction coefficient, the relation between interparticle friction coefficient and macroscopic continuum friction and dissipation is investigated. As expected, macroscopic friction and dilatancy increase with interparticle fri

  1. Solvable Quantum Macroscopic Motions and Decoherence Mechanisms in Quantum Mechanics on Nonstandard Space

    Science.gov (United States)

    Kobayashi, Tsunehiro

    1996-01-01

    Quantum macroscopic motions are investigated in the scheme consisting of N-number of harmonic oscillators in terms of ultra-power representations of nonstandard analysis. Decoherence is derived from the large internal degrees of freedom of macroscopic matters.

  2. Polyelectrolyte surfactant aggregates and their deposition on macroscopic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, David

    2002-07-01

    Oppositely charged surfactant and polyelectrolyte are present in hair shampoos and conditioners, together with particles (e.g. anti-dandruff agents for scalp) and droplets (e.g. silicone oil for the hair). These are normally formulated at high surfactant concentrations, beyond the flocculation region for the polyelectrolyte concentration used. However, on dilution with water, during application, flocs are formed which carry the particles and droplets to the scalp and hair. The addition of an anionic surfactant to an aqueous solution of cationic polyelectrolyte, at a given concentration, can lead to the formation of polyelectrolyte-surfactant 'particles', in which the surfactant 'binds' to the polyelectrolyte. This occurs from the critical association concentration (CAC), up to the surfactant concentration corresponding to maximum binding. Within this range of surfactant concentrations, the surfactant bound to the polyelectrolyte is thought to associate to form what might be termed 'internal micelles'. Each polyelectrolyte-surfactant particle in the region of the CAC, and just beyond, contains many polyelectrolyte chains, held together essentially by micelle bridges. These particles, however, remain net positively charged, and therefore stable. At the other end of the binding range of the surfactant, so many internal micelles are present that the polymer-surfactant particles are now net negatively charged. Indeed binding stops since no further micelles can be accommodated. Again, the particles are stable. However, there exists a range of surfactant concentrations, lying within the range referred to above, where the net charge is reduced sufficiently that the polymer-surfactant particles will flocculate to form much larger structures. The onset of this second range might be termed the 'critical flocculation concentration' (CFC), and the end, the 'critical stabilisation concentration' (CSC). In this work, the CFC and

  3. Macroscopic and microscopic spectral properties of brain networks during local and global synchronization

    Science.gov (United States)

    Maksimenko, Vladimir A.; Lüttjohann, Annika; Makarov, Vladimir V.; Goremyko, Mikhail V.; Koronovskii, Alexey A.; Nedaivozov, Vladimir; Runnova, Anastasia E.; van Luijtelaar, Gilles; Hramov, Alexander E.; Boccaletti, Stefano

    2017-07-01

    We introduce a practical and computationally not demanding technique for inferring interactions at various microscopic levels between the units of a network from the measurements and the processing of macroscopic signals. Starting from a network model of Kuramoto phase oscillators, which evolve adaptively according to homophilic and homeostatic adaptive principles, we give evidence that the increase of synchronization within groups of nodes (and the corresponding formation of synchronous clusters) causes also the defragmentation of the wavelet energy spectrum of the macroscopic signal. Our methodology is then applied to getting a glance into the microscopic interactions occurring in a neurophysiological system, namely, in the thalamocortical neural network of an epileptic brain of a rat, where the group electrical activity is registered by means of multichannel EEG. We demonstrate that it is possible to infer the degree of interaction between the interconnected regions of the brain during different types of brain activities and to estimate the regions' participation in the generation of the different levels of consciousness.

  4. Modeling of Macroscopic/Microscopic Transport and Growth Phenomena in Zeolite Crystal Solutions Under Microgravity Conditions

    Science.gov (United States)

    Gatsonis, Nikos A.; Alexandrou, Andreas; Shi, Hui; Ongewe, Bernard; Sacco, Albert, Jr.

    1999-01-01

    Crystals grown from liquid solutions have important industrial applications. Zeolites, for instance, a class of crystalline aluminosilicate materials, form the backbone of the chemical process industry worldwide, as they are used as adsorbents and catalysts. Many of the phenomena associated with crystal growth processes are not well understood due to complex microscopic and macroscopic interactions. Microgravity could help elucidate these phenomena and allow the control of defect locations, concentration, as well as size of crystals. Microgravity in an orbiting spacecraft could help isolate the possible effects of natural convection (which affects defect formation) and minimize sedimentation. In addition, crystals will stay essentially suspended in the nutrient pool under a diffusion-limited growth condition. This is expected to promote larger crystals by allowing a longer residence time in a high-concentration nutrient field. Among other factors, the crystal size distribution depends on the nucleation rate and crystallization. These two are also related to the "gel" polymerization/depolymerization rate. Macroscopic bulk mass and flow transport and especially gravity, force the crystals down to the bottom of the reactor, thus forming a sedimentation layer. In this layer, the growth rate of the crystals slows down as crystals compete for a limited amount of nutrients. The macroscopic transport phenomena under certain conditions can, however, enhance the nutrient supply and therefore, accelerate crystal growth. Several zeolite experiments have been performed in space with mixed results. The results from our laboratory have indicated an enhancement in size of 30 to 70 percent compared to the best ground based controls, and a reduction of lattice defects in many of the space grown crystals. Such experiments are difficult to interpret, and cannot be easily used to derive empirical or other laws since many physical parameters are simultaneously involved in the process

  5. Fractal Dimension and Universality in Avascular Tumor Growth

    OpenAIRE

    Ribeiro, Fabiano L.; Santos, Renato Vieira dos; Mata, Angélica S.

    2016-01-01

    The comprehension of tumor growth is a intriguing subject for scientists. New researches has been constantly required to better understand the complexity of this phenomenon. In this paper, we pursue a physical description that account for some experimental facts involving avascular tumor growth. We have proposed an explanation of some phenomenological (macroscopic) aspects of tumor, as the spatial form and the way it growths, from a individual-level (microscopic) formulation. The model propos...

  6. Mechanisms of Glioma Formation: Iterative Perivascular Glioma Growth and Invasion Leads to Tumor Progression, VEGF-Independent Vascularization, and Resistance to Antiangiogenic Therapy

    Directory of Open Access Journals (Sweden)

    Gregory J. Baker

    2014-07-01

    Full Text Available As glioma cells infiltrate the brain they become associated with various microanatomic brain structures such as blood vessels, white matter tracts, and brain parenchyma. How these distinct invasion patterns coordinate tumor growth and influence clinical outcomes remain poorly understood. We have investigated how perivascular growth affects glioma growth patterning and response to antiangiogenic therapy within the highly vascularized brain. Orthotopically implanted rodent and human glioma cells are shown to commonly invade and proliferate within brain perivascular space. This form of brain tumor growth and invasion is also shown to characterize de novo generated endogenous mouse brain tumors, biopsies of primary human glioblastoma (GBM, and peripheral cancer metastasis to the human brain. Perivascularly invading brain tumors become vascularized by normal brain microvessels as individual glioma cells use perivascular space as a conduit for tumor invasion. Agent-based computational modeling recapitulated biological perivascular glioma growth without the need for neoangiogenesis. We tested the requirement for neoangiogenesis in perivascular glioma by treating animals with angiogenesis inhibitors bevacizumab and DC101. These inhibitors induced the expected vessel normalization, yet failed to reduce tumor growth or improve survival of mice bearing orthotopic or endogenous gliomas while exacerbating brain tumor invasion. Our results provide compelling experimental evidence in support of the recently described failure of clinically used antiangiogenics to extend the overall survival of human GBM patients.

  7. Forskolin-induced differentiation of BeWo cells stimulates increased tumor growth in the chorioallantoic membrane (CAM) of the turkey (Meleagris gallopavo) egg.

    Science.gov (United States)

    Schneider, Ralf; Borges, Marcus; Kadyrov, Mamed

    2011-05-01

    Invasiveness of BeWo cells has been assessed in a variety of assay systems including matrigel and mouse. At the same time BeWo cells are mostly used as model system for trophoblast fusion. Here we aimed to test the properties of BeWo cells in a combined approach. We forced BeWo cells to differentiate by culturing the cells in the presence of forskolin and then used these cells for invasion assays on the chorioallantoic membrane (CAM) of the turkey. The chorioallantoic membranes of turkey eggs were incubated with medium containing forskolin, BeWo cells cultured in medium alone, BeWo cells cultured in forskolin and washed, and BeWo cells cultured in forskolin and used directly for application. Suspensions were applied onto ten CAM per condition. For local tumor formation eggs were checked for tumor development every 24h macroscopically for up to 12 days and immunohistochemistry for cytokeratin 18 and Ki-67 were used for further analysis. Forskolin alone did not have any deleterious effect on the CAM. When the CAM was incubated with BeWo cells cultured in medium 40% of the eggs developed a macroscopically visible tumor. BeWo cells stimulated with forskolin and washed induced tumor growth in 50% of the eggs, while forskolin stimulated BeWo cells applied directly onto the CAM induced tumor growth in 70% of the eggs. Forced differentiation of BeWo cells by forskolin may lead to syncytial fusion in a plastic culture dish. Under the conditions used here, i.e. in direct contact to a living tissue, forskolin-induced differentiation of BeWo cells leads to an increase in tumor formation in the CAM. Thus BeWo cells may use signaling pathways to decide for both differentiation pathways similar to primary trophoblast depending on the environment.

  8. Understanding the Pulsar High Energy Emission: Macroscopic and Kinetic Models

    Science.gov (United States)

    Kalapotharakos, Constantinos; Brambilla, Gabriele; Timokhin, Andrey; Kust Harding, Alice; Kazanas, Demos

    2017-08-01

    Pulsars are extraordinary objects powered by the rotation of magnetic fields of order 10^8, 10^12G anchored onto neutron stars and rotating with periods 10^(-3)-10s. These fields mediate the conversion of their rotational energy into MHD winds and at the same time accelerate particles to energies sufficiently high to produce GeV photons. Fermi, since its launch in 2008, has established several trends among the observed gamma-ray pulsar properties playing a catalytic role in the current modeling of the high energy emission in pulsar magnetospheres. We judiciously use the guidance provided by the Fermi data to yield meaningful constraints on the macroscopic parameters of our global dissipative pulsar magnetosphere models. Our FIDO (Force-Free Inside, Dissipative Outside) models indicate that the dissipative regions lie outside the light cylinder near the equatorial current sheet. Our models reproduce the light-curve phenomenology while a detailed comparison of the model spectral properties with those observed by Fermi reveals the dependence of the macroscopic conductivity parameter on the spin-down rate providing a unique insight into the understanding of the physical mechanisms behind the high-energy emission in pulsar magnetospheres. Finally, we further exploit these important results by building self-consistent 3D global kinetic particle-in-cell (PIC) models which, eventually, provide the dependence of the macroscopic parameter behavior (e.g. conductivity) on the microphysical properties (e.g. particle multiplicities, particle injection rates). Our PIC models provide field structures and particle distributions that are not only consistent with each other but also able to reproduce a broad range of the observed gamma-ray phenomenology (light curves and spectral properties) of both young and millisecond pulsars.

  9. How mesoscopic staircases condense to macroscopic barriers in confined plasma turbulence

    Science.gov (United States)

    Ashourvan, Arash; Diamond, P. H.

    2016-11-01

    This Rapid Communication sets forth the mechanism by which mesoscale staircase structures condense to form macroscopic states of enhanced confinement. Density, vorticity, and turbulent potential enstrophy are the variables for this model. Formation of the staircase structures is due to inhomogeneous mixing of (generalized) potential vorticity (PV). Such mixing results in the local sharpening of density and vorticity gradients. When PV gradients steepen, the density staircase structure develops into a lattice of mesoscale "jumps" and "steps," which are, respectively, regions of local gradient steepening and flattening. The jumps then merge and migrate in radius, leading to the emergence of a new macroscale profile structure, so indicating that profile self-organization is a global process, which may be described by a local, but nonlinear model. This work predicts and demonstrates how mesoscale condensation of staircases leads to global states of enhanced confinement.

  10. External and internal gelation of pectin solutions: microscopic dynamics versus macroscopic rheology

    Science.gov (United States)

    Secchi, E.; Munarin, F.; Alaimo, M. D.; Bosisio, S.; Buzzaccaro, S.; Ciccarella, G.; Vergaro, V.; Petrini, P.; Piazza, R.

    2014-11-01

    Pectin is a natural biopolymer that forms, in the presence of divalent cations, ionic-bound gels typifying a large class of biological gels stabilized by non-covalent cross-links. We investigate and compare the kinetics of formation and aging of pectin gels obtained either through external gelation via perfusion of free Ca2+ ions, or by internal gelation due to the supply of the same ions from the dissolution of CaCO3 nanoparticles. The microscopic dynamics obtained with photon correlation imaging, a novel optical technique that allows obtaining the microscopic dynamics of the sample while retaining the spatial resolution of imaging techniques, is contrasted with macroscopic rheological measurements at constant strain. Pectin gelation is found to display peculiar two-stage kinetics, highlighted by non-monotonic growth in time of both microscopic correlations and gel mechanical strength. These results are compared to those found for alginate, another biopolymer extensively used in food formulation.

  11. Macroscopic Ordering of CNTs in a Liquid Crystalline Polymer Nano-Composite by Shearing

    Science.gov (United States)

    Kalakonda, P.; Sarkar, S.; Iannacchione, G. S.; Gombos, E.; Hoonjan, G. S.; Georgiev, G.; Cebe, P.

    2012-02-01

    We present a series of complimentary experiments exploring the macroscopic alignment of carbon nanotubes (CNTs) in a liquid crystalline polymer (isotactic polypropylene - iPP) nano-composites as a function of temperature, shear, and CNT concentration. The phase behavior of iPP+CNT, studied by Modulated Differential Scanning Calorimetry, revealed the evolution of the α-monoclinic transition and its dynamics, which are dependent on CNT content and thermal treatment. These results indicate that the CNT nucleates crystal formation from the melt. Spectroscopic ellipsometry reveals a change in the optical constants that are connected to the ordering of CNTs when the iPP+CNT is sheared. This anisotropy is also exhibited in measurements of the electrical and thermal conductivities parallel and perpendicular to the shear direction. The amount of order induced into the dispersed CNTs is relatively low for these low concentration samples (< 5 wt%).

  12. External and internal gelation of pectin solutions: microscopic dynamics versus macroscopic rheology.

    Science.gov (United States)

    Secchi, E; Munarin, F; Alaimo, M D; Bosisio, S; Buzzaccaro, S; Ciccarella, G; Vergaro, V; Petrini, P; Piazza, R

    2014-11-19

    Pectin is a natural biopolymer that forms, in the presence of divalent cations, ionic-bound gels typifying a large class of biological gels stabilized by non-covalent cross-links. We investigate and compare the kinetics of formation and aging of pectin gels obtained either through external gelation via perfusion of free Ca(2+) ions, or by internal gelation due to the supply of the same ions from the dissolution of CaCO3 nanoparticles. The microscopic dynamics obtained with photon correlation imaging, a novel optical technique that allows obtaining the microscopic dynamics of the sample while retaining the spatial resolution of imaging techniques, is contrasted with macroscopic rheological measurements at constant strain. Pectin gelation is found to display peculiar two-stage kinetics, highlighted by non-monotonic growth in time of both microscopic correlations and gel mechanical strength. These results are compared to those found for alginate, another biopolymer extensively used in food formulation.

  13. Single-atom quantum control of macroscopic mechanical oscillators

    Science.gov (United States)

    Bariani, F.; Otterbach, J.; Tan, Huatang; Meystre, P.

    2014-01-01

    We investigate a hybrid electromechanical system consisting of a pair of charged macroscopic mechanical oscillators coupled to a small ensemble of Rydberg atoms. The resonant dipole-dipole coupling between an internal atomic Rydberg transition and the mechanics allows cooling to its motional ground state with a single atom despite the considerable mass imbalance between the two subsystems. We show that the rich electronic spectrum of Rydberg atoms, combined with their high degree of optical control, paves the way towards implementing various quantum-control protocols for the mechanical oscillators.

  14. The Two-Time Interpretation and Macroscopic Time-Reversibility

    Directory of Open Access Journals (Sweden)

    Yakir Aharonov

    2017-03-01

    Full Text Available The two-state vector formalism motivates a time-symmetric interpretation of quantum mechanics that entails a resolution of the measurement problem. We revisit a post-selection-assisted collapse model previously suggested by us, claiming that unlike the thermodynamic arrow of time, it can lead to reversible dynamics at the macroscopic level. In addition, the proposed scheme enables us to characterize the classical-quantum boundary. We discuss the limitations of this approach and its broad implications for other areas of physics.

  15. Emergence of an urban traffic macroscopic fundamental diagram

    DEFF Research Database (Denmark)

    Ranjan, Abhishek; Fosgerau, Mogens; Jenelius, Erik

    2016-01-01

    This paper examines mild conditions under which a macroscopic fundamental diagram (MFD) emerges, relating space-averaged speed to occupancy in some area. These conditions are validated against empirical data. We allow local speedoccupancy relationships and, in particular, require no equilibrating...... process to be in operation. This means that merely observing the stable relationship between the space-averages of speed, flow and occupancy are not sufficient to infer a robust relationship and the emerging MFD cannot be guaranteed to be stable if traffic interventions are implemented....

  16. Violation of smooth observable macroscopic realism in a harmonic oscillator.

    Science.gov (United States)

    Leshem, Amir; Gat, Omri

    2009-08-14

    We study the emergence of macrorealism in a harmonic oscillator subject to consecutive measurements of a squeezed action. We demonstrate a breakdown of dynamical realism in a wide parameter range that is maximized in a scaling limit of extreme squeezing, where it is based on measurements of smooth observables, implying that macroscopic realism is not valid in the harmonic oscillator. We propose an indirect experimental test of these predictions with entangled photons by demonstrating that local realism in a composite system implies dynamical realism in a subsystem.

  17. Seismic scanning tunneling macroscope - Elastic simulations and Arizona mine test

    KAUST Repository

    Hanafy, Sherif M.

    2012-01-01

    Elastic seismic simulations and field data tests are used to validate the theory of a seismic scanning tunneling macroscope (SSTM). For nearfield elastic simulation, the SSTM results show superresolution to be better than λ/8 if the only scattered data are used as input data. If the direct P and S waves are muted then the resolution of the scatterer locations are within about λ/5. Seismic data collected in an Arizona tunnel showed a superresolution limit of at least λ/19. These test results are consistent with the theory of the SSTM and suggest that the SSTM can be a tool used by geophysicists as a probe for near-field scatterers.

  18. Macroscopic description of teeth of Azara's agouti (Dasyprocta azarae

    Directory of Open Access Journals (Sweden)

    Fabrício S. Oliveira

    2012-01-01

    Full Text Available The teeth of Azara's agouti (Dasyprocta azarae were described macroscopically in order to provide biological data on one of the largest wild rodents of the Americas. Radiography was taken on six heads and the teeth were described. Enamel surrounds the coronal dentin, projects to the roots and is present as parallel inner laminae in buccolingual direction. The dentin is located among the enamel laminae and surrounds the pulp horns. The cementum is located internally to the enamel laminae. On the lingual surface, the cementum and dentin are the outer elements.

  19. Macroscopic and microscopic self-organization by nonlocal anisotropic interactions

    CERN Document Server

    Cristiani, Emiliano; Tosin, Andrea

    2009-01-01

    This paper is concerned with mathematical modeling of intelligent systems, such as human crowds and animal groups. In particular, the focus is on the emergence of different self-organized patterns from non-locality and anisotropy of the interactions among individuals. A mathematical technique by time-evolving measures is introduced to deal with both macroscopic and microscopic scales within a unified modeling framework. Then self-organization issues are investigated and numerically reproduced at the proper scale, according to the kind of agents under consideration.

  20. An investigation into why macroscopic systems behave classically

    OpenAIRE

    Hallwood, David W.; Burnett, Keith; Dunningham, Jacob

    2006-01-01

    We study why it is quite so hard to make a superposition of superfluid flows in a Bose-Einstein condensate. To do this we initially investigate the quantum states of $N$ atoms trapped in a 1D ring with a barrier at one position and a phase applied around it. We show how macroscopic superpositions can in principle be produced and investigate factors which affect the superposition. We then use the Bose-Hubbard model to study an array of Bose-Einstein condensates trapped in optical potentials an...

  1. Measurement-induced macroscopic superposition states in cavity optomechanics

    CERN Document Server

    Hoff, Ulrich B; Neergaard-Nielsen, Jonas S; Andersen, Ulrik L

    2016-01-01

    We present a novel proposal for generating quantum superpositions of macroscopically distinct states of a bulk mechanical oscillator, compatible with existing optomechanical devices operating in the readily achievable bad-cavity limit. The scheme is based on a pulsed cavity optomechanical quantum non-demolition (QND) interaction, driven by displaced non-Gaussian states, and measurement-induced feedback, avoiding the need for strong single-photon optomechanical coupling. Furthermore, we show that single-quadrature cooling of the mechanical oscillator is sufficient for efficient state preparation, and we outline a three-pulse protocol comprising a sequence of QND interactions for squeezing-enhanced cooling, state preparation, and tomography.

  2. Flagella bending affects macroscopic properties of bacterial suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Potomkin, M.; Tournus, M.; Berlyand, L. V.; Aranson, I. S.

    2017-05-01

    To survive in harsh conditions, motile bacteria swim in complex environments and respond to the surrounding flow. Here, we develop a mathematical model describing how flagella bending affects macroscopic properties of bacterial suspensions. First, we show how the flagella bending contributes to the decrease in the effective viscosity observed in dilute suspension. Our results do not impose tumbling (random reorientation) as was previously done to explain the viscosity reduction. Second, we demonstrate how a bacterium escapes from wall entrapment due to the self-induced buckling of flagella. Our results shed light on the role of flexible bacterial flagella in interactions of bacteria with shear flow and walls or obstacles.

  3. Modelling and simulations of macroscopic multi-group pedestrian flow

    CERN Document Server

    Mahato, Naveen K; Tiwari, Sudarshan

    2016-01-01

    We consider a multi-group microscopic model for pedestrian flow describing the behaviour of large groups. It is based on an interacting particle system coupled to an eikonal equation. Hydrodynamic multi-group models are derived from the underlying particle system as well as scalar multi-group models. The eikonal equation is used to compute optimal paths for the pedestrians. Particle methods are used to solve the macroscopic equations. Numerical test cases are investigated and the models and, in particular, the resulting evacuation times are compared for a wide range of different parameters.

  4. Macroscopic modeling for traffic flow on three-lane highways

    Science.gov (United States)

    Chen, Jianzhong; Fang, Yuan

    2015-04-01

    In this paper, a macroscopic traffic flow model for three-lane highways is proposed. The model is an extension of the speed gradient model by taking into account the lane changing. The new source and sink terms of lane change rate are added into the continuity equations and the speed dynamic equations to describe the lane-changing behavior. The result of the steady state analysis shows that our model can describe the lane usage inversion phenomenon. The numerical results demonstrate that the present model effectively reproduces several traffic phenomena observed in real traffic such as shock and rarefaction waves, stop-and-go waves and local clusters.

  5. Macroscopic flame structure in a premixed-spray burner. 1st Report. formation and disappearance processes of droplet clusters and two-stage flame structure; Yokongo funmu kaen no kyoshiteki nensho kyodo. 1. Yuteki cluster no keisei shoshitsu katei to niju kaen kozo

    Energy Technology Data Exchange (ETDEWEB)

    Tsushima, S.; Saito, H.; Akamatsu, F.; Katsuki, M. [Osaka University, Osaka (Japan)

    2000-08-25

    In an attempt to elucidate formation and disappearance processes of droplet clusters in spray flames, simultaneous measurements consisting of laser tomography and flame chemiluminescence detection are applied to a premixed-spay burner. The smart combination of measurements provides time-series data-set serving for better understanding of spray flames, which essentially contains inhomogeneity in space and time. It is revealed that referential flame propagation through a premixed-spray stream plays a significant role in creating droplet clusters and that droplet clusters formed in this manner evanesces from their outer boundaries. Those observation confirms that the premixed-spray flame comprises both premixed-mode flame in upstream region and diffusion-mode flame in downstream region, respectively, i.e, two-stage flame structure previously reported for spray flames stabilized in either counter or stagnation flows. (author)

  6. Wilms Tumor

    Science.gov (United States)

    Wilms tumor is a rare type of kidney cancer. It causes a tumor on one or both kidneys. It usually affects ... are at risk should be screened for Wilms tumor every three months until they turn eight. Symptoms ...

  7. Macroscopic and histologic evaluation of a rat model of chronic rotator cuff tear.

    Science.gov (United States)

    Hashimoto, Eiko; Ochiai, Nobuyasu; Kenmoku, Tomonori; Sasaki, Yu; Yamaguchi, Takeshi; Kijima, Takehiro; Sasaki, Yasuhito; Ohtori, Seiji; Takahashi, Kazuhisa

    2016-12-01

    The major cause of rotator cuff tears in humans is thought to be tendon degeneration. Although some studies have reported chronic rotator cuff tear models in animals, few studies of chronic rat models have demonstrated persistent defects for a relatively long time. The purpose of this study was to establish a chronic rotator cuff tear model in the rat and to evaluate the model macroscopically and histologically. Sixty Sprague Dawley rats were divided into 2 groups: tendon detachment only (tear group) and tendon detachment plus figure resin (chronic group). The contralateral shoulder served as a sham-operated control (sham group). In the tear group, the supraspinatus and infraspinatus tendons were completely detached. In addition to cuff detachment, figure resin was placed on the greater tuberosity to prevent cuff reattachment and scar formation in the chronic group. Macroscopic and histologic changes were assessed at 4 and 12 weeks after surgery. A full-thickness cuff defect was observed in all chronic-group rats at both 4 and 12 weeks after surgery, and it could be repaired secondarily by traction in lower tension. However, no cuff defects were observed in the tear group because of obvious scar tissue formation. On histologic evaluation, progressive tendon degeneration, muscle atrophy, and fatty infiltration were observed in the chronic model at 12 weeks after surgery. We established a rat model of chronic rotator cuff tears using figure resin. This chronic rotator cuff tear model might be useful for further clinical investigations of rotator cuff repair. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  8. Macroscopic Quantum Phenomena from the Correlation, Coupling and Criticality Perspectives

    CERN Document Server

    Chou, C H; Subasi, Y

    2011-01-01

    In this sequel paper we explore how macroscopic quantum phenomena can be measured or understood from the behavior of quantum correlations which exist in a quantum system of many particles or components and how the interaction strengths change with energy or scale, under ordinary situations and when the system is near its critical point. We use the nPI (master) effective action related to the Boltzmann-BBGKY / Schwinger-Dyson hierarchy of equations as a tool for systemizing the contributions of higher order correlation functions to the dynamics of lower order correlation functions. Together with the large N expansion discussed in our first paper(MQP1) we explore 1) the conditions whereby an H-theorem is obtained, which can be viewed as a signifier of the emergence of macroscopic behavior in the system. We give two more examples from past work: 2) the nonequilibrium dynamics of N atoms in an optical lattice under the large $\\cal N$ (field components), 2PI and second order perturbative expansions, illustrating h...

  9. Macroscopic superposition states and decoherence by quantum telegraph noise

    Energy Technology Data Exchange (ETDEWEB)

    Abel, Benjamin Simon

    2008-12-19

    In the first part of the present thesis we address the question about the size of superpositions of macroscopically distinct quantum states. We propose a measure for the ''size'' of a Schroedinger cat state, i.e. a quantum superposition of two many-body states with (supposedly) macroscopically distinct properties, by counting how many single-particle operations are needed to map one state onto the other. We apply our measure to a superconducting three-junction flux qubit put into a superposition of clockwise and counterclockwise circulating supercurrent states and find this Schroedinger cat to be surprisingly small. The unavoidable coupling of any quantum system to many environmental degrees of freedom leads to an irreversible loss of information about an initially prepared superposition of quantum states. This phenomenon, commonly referred to as decoherence or dephasing, is the subject of the second part of the thesis. We have studied the time evolution of the reduced density matrix of a two-level system (qubit) subject to quantum telegraph noise which is the major source of decoherence in Josephson charge qubits. We are able to derive an exact expression for the time evolution of the reduced density matrix. (orig.)

  10. Tribological behaviour of graphite powders at nano- and macroscopic scales

    Science.gov (United States)

    Schmitt, M.; Bistac, S.; Jradi, K.

    2007-04-01

    With its high resistance, good hardness and electrical conductibility in the basal plans, graphite is used for many years in various tribological fields such as seals, bearings or electrical motor brushes, and also for applications needing excellent lubrication and wearreducing properties. But thanks to its low density, graphite is at the moment destined for technologies which need a reducing of the weight combined with an enhancement of the efficiency, as it is the case in aeronautical industry. In this contexte, the friction and wear of natural (named graphite A) and synthetic (called graphites B and C) powders were evaluated, first at the macroscopic scale when sliding against steel counterfaces, under various applied normal loads. Scanning Electron Microscopy and AFM in tapping mode were used to observe the morphological modifications of the graphites. It is noticed that an enlargement of the applied normal load leads to an increase of the friction coefficient for graphites A and C; but for the graphite B, it seems that a ''limit'' load can induce a complete change of the tribological behaviour. At the same time, the nano-friction properties of these powders were evaluated by AFM measurements in contact mode, at different contact loads. As it was the case at the macroscopic scale, an increase of the nano-contact load induces higher friction coefficients. The determining of the friction and wear mechanisms of the graphite powders, as a function of both their intrinsic characteristics and the applied normal load, is then possible.

  11. How does Planck’s constant influence the macroscopic world?

    Science.gov (United States)

    Yang, Pao-Keng

    2016-09-01

    In physics, Planck’s constant is a fundamental physical constant accounting for the energy-quantization phenomenon in the microscopic world. The value of Planck’s constant also determines in which length scale the quantum phenomenon will become conspicuous. Some students think that if Planck’s constant were to have a larger value than it has now, the quantum effect would only become observable in a world with a larger size, whereas the macroscopic world might remain almost unchanged. After reasoning from some basic physical principles and theories, we found that doubling Planck’s constant might result in a radical change on the geometric sizes and apparent colors of macroscopic objects, the solar spectrum and luminosity, the climate and gravity on Earth, as well as energy conversion between light and materials such as the efficiency of solar cells and light-emitting diodes. From the discussions in this paper, students can appreciate how Planck’s constant affects various aspects of the world in which we are living now.

  12. Macroscopic Biological Characteristics of Individualized Therapy in Chinese Mongolian Osteopathy

    Science.gov (United States)

    Namula, Zhao; Mei, Wang; Li, Xue-en

    Objective: Chinese Mongolian osteopathy has been passed down from ancient times and includes unique practices and favorable efficacy. In this study, we investigate the macroscopic biological characteristics of individualized Chinese Mongolian osteopathy, in order to provide new principle and methods for the treatment of bone fracture. Method: With a view to provide a vital link between nature and humans, the four stages of Chinese Mongolian osteopathy focus on the unity of the mind and body, the limbs and body organs, the body and its functions, and humans and nature. Results: We discuss the merits of individualized osteopathy in terms of the underlying concepts, and evaluate the approaches and principles of traditional medicine, as well as biomechanics. Conclusions: Individualized Mongolian osteopathy targets macroscopic biological components including dynamic reduction, natural fixation, and functional healing. Chinese Mongolian osteopathy is a natural, ecological and non-invasive osteopathy that values the link between nature and humans, including the unity of mind and body. The biological components not only serve as a foundation for Chinese Mongolian osteopathy but are also important for the future development of modern osteopathy, focusing on individualization, actualization and integration.

  13. Motion of macroscopic bodies in the electromagnetic field

    CERN Document Server

    Horsley, S A R

    2013-01-01

    A theory is presented for calculating the effect of the electromagnetic field on the centre of mass of a macroscopic dielectric body that is valid in both quantum and classical regimes. We apply the theory to find the classical equation of motion for the centre of mass of a macroscopic object in a classical field, and the spreading of an initially localized wave-packet representing the centre of mass of a small object, in a quantum field. The classical force is found to be consistent with the identification of the Abraham momentum with the mechanical momentum of light, and the motion of the wave-packet is found to be subject to an acceleration due to the Casimir force, and a time dependent fluctuating motion due the creation of pairs of excitations within the object. The theory is valid for any dielectric that has susceptibilities satisfying the Kramers-Kronig relations, and is not subject to arguments regarding the form of the electromagnetic energy-momentum tensor within a medium.

  14. Parametric equations for calculation of macroscopic cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Mario Hugo; Carvalho, Fernando, E-mail: mariobotelho@poli.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2015-07-01

    Neutronic calculations of the core of a nuclear reactor is one thing necessary and important for the design and management of a nuclear reactor in order to prevent accidents and control the reactor efficiently as possible. To perform these calculations a library of nuclear data, including cross sections is required. Currently, to obtain a cross section computer codes are used, which require a large amount of processing time and computer memory. This paper proposes the calculation of macroscopic cross section through the development of parametric equations. The paper illustrates the proposal for the case of macroscopic cross sections of absorption (Σa), which was chosen due to its greater complexity among other cross sections. Parametric equations created enable, quick and dynamic way, the determination of absorption cross sections, enabling the use of them in calculations of reactors. The results show efficient when compared with the absorption cross sections obtained by the ALPHA 8.8.1 code. The differences between the cross sections are less than 2% for group 2 and less than 0.60% for group 1. (author)

  15. An exploration for the macroscopic physical meaning of entropy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The macroscopic physical meaning of entropy is analyzed based on the exergy (availability) of a combined system (a closed system and its environment), which is the maximum amount of useful work obtainable from the system and the environment as the system is brought into equilibrium with the environment. The process the system experiences can be divided in two sequent sub-processes, the process at constant volume, which represents the heat interaction of the system with the environment, and the adiabatic process, which represents the work interaction of the system with the environment. It is shown that the macroscopic physical meaning of entropy is a measure of the unavailable energy of a closed system for doing useful work through heat interaction. This statement is more precise than those reported in prior literature. The unavailability function of a closed system can be defined as T0S and p0V in volume constant process and adiabatic process, respectively. Their changes, that is, AiTgS) and A (p0V) represent the unusable parts of the internal energy of a closed system for doing useful work in corresponding processes. Finally, the relation between Clausius entropy and Boltzmann entropy is discussed based on the comparison of their expressions for absolute entropy.

  16. Macroscopic model and truncation error of discrete Boltzmann method

    Science.gov (United States)

    Hwang, Yao-Hsin

    2016-10-01

    A derivation procedure to secure the macroscopically equivalent equation and its truncation error for discrete Boltzmann method is proffered in this paper. Essential presumptions of two time scales and a small parameter in the Chapman-Enskog expansion are disposed of in the present formulation. Equilibrium particle distribution function instead of its original non-equilibrium form is chosen as key variable in the derivation route. Taylor series expansion encompassing fundamental algebraic manipulations is adequate to realize the macroscopically differential counterpart. A self-contained and comprehensive practice for the linear one-dimensional convection-diffusion equation is illustrated in details. Numerical validations on the incurred truncation error in one- and two-dimensional cases with various distribution functions are conducted to verify present formulation. As shown in the computational results, excellent agreement between numerical result and theoretical prediction are found in the test problems. Straightforward extensions to more complicated systems including convection-diffusion-reaction, multi-relaxation times in collision operator as well as multi-dimensional Navier-Stokes equations are also exposed in the Appendix to point out its expediency in solving complicated flow problems.

  17. Inverted rank distributions: Macroscopic statistics, universality classes, and critical exponents

    Science.gov (United States)

    Eliazar, Iddo; Cohen, Morrel H.

    2014-01-01

    An inverted rank distribution is an infinite sequence of positive sizes ordered in a monotone increasing fashion. Interlacing together Lorenzian and oligarchic asymptotic analyses, we establish a macroscopic classification of inverted rank distributions into five “socioeconomic” universality classes: communism, socialism, criticality, feudalism, and absolute monarchy. We further establish that: (i) communism and socialism are analogous to a “disordered phase”, feudalism and absolute monarchy are analogous to an “ordered phase”, and criticality is the “phase transition” between order and disorder; (ii) the universality classes are characterized by two critical exponents, one governing the ordered phase, and the other governing the disordered phase; (iii) communism, criticality, and absolute monarchy are characterized by sharp exponent values, and are inherently deterministic; (iv) socialism is characterized by a continuous exponent range, is inherently stochastic, and is universally governed by continuous power-law statistics; (v) feudalism is characterized by a continuous exponent range, is inherently stochastic, and is universally governed by discrete exponential statistics. The results presented in this paper yield a universal macroscopic socioeconophysical perspective of inverted rank distributions.

  18. Macroscopic Behavior of Nematics with D2d Symmetry

    Science.gov (United States)

    Pleiner, Harald; Brand, Helmut R.

    2010-03-01

    We discuss the symmetry properties and the macroscopic behavior of a nematic liquid crystal phase with D2d symmetry. Such a phase is a prime candidate for nematic phases made from banana-shaped molecules where the usual quadrupolar order coexists with octupolar (tetrahedratic) order. The resulting nematic phase is non-polar. While this phase could resemble the classic D∞h nematic in the polarizing microscope, it has many static as well as reversible and irreversible properties unknown to non-polar nematics without octupolar order. In particular, there is a linear gradient term in the free energy that selects parity leading to ambidextrously helical ground states when the molecules are achiral. In addition, there are static and irreversible coupling terms of a type only met otherwise in macroscopically chiral liquid crystals, e.g. the ambidextrous analogues of Lehmann-type effects known from cholesteric liquid crystals. Finally, we discuss certain nonlinear aspects of the dynamics related to the non-commutativity of three-dimensional finite rotations as well as other structural nonlinear hydrodynamic effects.

  19. Nanoscale patterning, macroscopic reconstruction, and enhanced surface stress by organic adsorption on vicinal surfaces

    Science.gov (United States)

    Pollinger, Florian; Schmitt, Stefan; Sander, Dirk; Tian, Zhen; Kirschner, Jürgen; Vrdoljak, Pavo; Stadler, Christoph; Maier, Florian; Marchetto, Helder; Schmidt, Thomas; Schöll, Achim; Umbach, Eberhard

    2017-01-01

    Self-organization is a promising method within the framework of bottom-up architectures to generate nanostructures in an efficient way. The present work demonstrates that self-organization on the length scale of a few to several tens of nanometers can be achieved by a proper combination of a large (organic) molecule and a vicinal metal surface if the local bonding of the molecule on steps is significantly stronger than that on low-index surfaces. In this case thermal annealing may lead to large mass transport of the subjacent substrate atoms such that nanometer-wide and micrometer-long molecular stripes or other patterns are being formed on high-index planes. The formation of these patterns can be controlled by the initial surface orientation and adsorbate coverage. The patterns arrange self-organized in regular arrays by repulsive mechanical interactions over long distances accompanied by a significant enhancement of surface stress. We demonstrate this effect using the planar organic molecule PTCDA as adsorbate and Ag(10 8 7) and Ag(775) surfaces as substrate. The patterns are directly observed by STM, the formation of vicinal surfaces is monitored by high-resolution electron diffraction, the microscopic surface morphology changes are followed by spectro-microscopy, and the macroscopic changes of surface stress are measured by a cantilever bending method. The in situ combination of these complementary techniques provides compelling evidence for elastic interaction and a significant stress contribution to long-range order and nanopattern formation.

  20. [Resection of Klatskin tumors].

    Science.gov (United States)

    Seehofer, D; Kamphues, C; Neuhaus, P

    2012-03-01

    Curative treatment of Klatskin tumors by radical surgical procedures with surgical preparation distant to the tumor region results in 5-year survival rates of 30-50%. This requires mandatory en bloc liver resection and resection of the extrahepatic bile duct often together with vascular resection. Nevertheless, the ideal safety margin of 0.5-1 cm remote from the macroscopic tumor extensions cannot be achieved in all cases. Based on hilar anatomy the probability of an adequate safety margin is higher using extended right hemihepatectomy together with portal vein resection compared to left hemihepatectomy. However, due to severe atrophy of the left liver lobe solely left-sided hepatectomy is feasible in some patients. In cases of eligibility for both procedures right hemihepatectomy is preferentially used due to the higher oncological radicality if sufficient liver function is present. Postoperative hepatic insufficiency and bile leakage after demanding biliary reconstruction, often with several small orifices, contribute to the postoperative complication rate of this complex surgical disease pattern.

  1. Pituitary Tumors

    Science.gov (United States)

    ... institutes of the National Institutes of Health (NIH) conduct research related to brain tumors, including pituitary tumors, in their laboratories at ... institutes of the National Institutes of Health (NIH) conduct research related to brain tumors, including pituitary tumors, in their laboratories at ...

  2. Symmetry properties of macroscopic transport coefficients in porous media

    Science.gov (United States)

    Lasseux, D.; Valdés-Parada, F. J.

    2017-04-01

    We report on symmetry properties of tensorial effective transport coefficients characteristic of many transport phenomena in porous systems at the macroscopic scale. The effective coefficients in the macroscopic models (derived by upscaling (volume averaging) the governing equations at the underlying scale) are obtained from the solution of closure problems that allow passing the information from the lower to the upper scale. The symmetry properties of the macroscopic coefficients are identified from a formal analysis of the closure problems and this is illustrated for several different physical mechanisms, namely, one-phase flow in homogeneous porous media involving inertial effects, slip flow in the creeping regime, momentum transport in a fracture relying on the Reynolds model including slip effects, single-phase flow in heterogeneous porous media embedding a porous matrix and a clear fluid region, two-phase momentum transport in homogeneous porous media, as well as dispersive heat and mass transport. The results from the analysis of these study cases are summarized as follows. For inertial single-phase flow, the apparent permeability tensor is irreducibly decomposed into its symmetric (viscous) and skew-symmetric (inertial) parts; for creeping slip-flow, the apparent permeability tensor is not symmetric; for one-phase slightly compressible gas flow in the slip regime within a fracture, the effective transmissivity tensor is symmetric, a result that remains valid in the absence of slip; for creeping one-phase flow in heterogeneous media, the permeability tensor is symmetric; for two-phase flow, we found the dominant permeability tensors to be symmetric, whereas the coupling tensors do not exhibit any special symmetry property; finally for dispersive heat transfer, the thermal conductivity tensors include a symmetric and a skew-symmetric part, the latter being a consequence of convective transport only. A similar result is achieved for mass dispersion. Beyond the

  3. Activation of the FGFR-STAT3 pathway in breast cancer cells induces a hyaluronan-rich microenvironment that licenses tumor formation.

    Science.gov (United States)

    Bohrer, Laura R; Chuntova, Pavlina; Bade, Lindsey K; Beadnell, Thomas C; Leon, Ronald P; Brady, Nicholas J; Ryu, Yungil; Goldberg, Jodi E; Schmechel, Stephen C; Koopmeiners, Joseph S; McCarthy, James B; Schwertfeger, Kathryn L

    2014-01-01

    Aberrant activation of fibroblast growth factor receptors (FGFR) contributes to breast cancer growth, progression, and therapeutic resistance. Because of the complex nature of the FGF/FGFR axis, and the numerous effects of FGFR activation on tumor cells and the surrounding microenvironment, the specific mechanisms through which aberrant FGFR activity contributes to breast cancer are not completely understood. We show here that FGFR activation induces accumulation of hyaluronan within the extracellular matrix and that blocking hyaluronan synthesis decreases proliferation, migration, and therapeutic resistance. Furthermore, FGFR-mediated hyaluronan accumulation requires activation of the STAT3 pathway, which regulates expression of hyaluronan synthase 2 (HAS2) and subsequent hyaluronan synthesis. Using a novel in vivo model of FGFR-dependent tumor growth, we demonstrate that STAT3 inhibition decreases both FGFR-driven tumor growth and hyaluronan levels within the tumor. Finally, our results suggest that combinatorial therapies inhibiting both FGFR activity and hyaluronan synthesis is more effective than targeting either pathway alone and may be a relevant therapeutic approach for breast cancers associated with high levels of FGFR activity. In conclusion, these studies indicate a novel targetable mechanism through which FGFR activation in breast cancer cells induces a protumorigenic microenvironment.

  4. Macroscopic Modeling of Transport Phenomena in Direct Methanol Fuel Cells

    DEFF Research Database (Denmark)

    Olesen, Anders Christian

    An increasing need for energy efficiency and high energy density has sparked a growing interest in direct methanol fuel cells for portable power applications. This type of fuel cell directly generates electricity from a fuel mixture consisting of methanol and water. Although this technology...... for studying their transport. In this PhD dissertation the macroscopic transport phenomena governing direct methanol fuel cell operation are analyzed, discussed and modeled using the two-fluid approach in the computational fluid dynamics framework of CFX 14. The overall objective of this work is to extend...... the present fundamental understanding of direct methanol fuel cell operation by developing a three-dimensional, two-phase, multi-component, non-isotherm mathematical model including detailed non-ideal thermodynamics, non-equilibrium phase change and non-equilibrium sorption-desorption of methanol and water...

  5. Macroscopic quantum electrodynamics of high-Q cavities

    Energy Technology Data Exchange (ETDEWEB)

    Khanbekyan, Mikayel

    2009-10-27

    In this thesis macroscopic quantum electrodynamics in linear media was applied in order to develop an universally valid quantum theory for the description of the interaction of the electromagnetic field with atomic sources in high-Q cavities. In this theory a complete description of the characteristics of the emitted radiation is given. The theory allows to show the limits of the applicability of the usually applied theory. In order to establish an as possible generally valid theory first the atom-field interaction was studied in the framework of macroscopic quantum electrodynamics in dispersive and absorptive media. In order to describe the electromagnetic field from Maxwell's equations was started, whereby the noise-current densities, which are connected with the absorption of the medium, were included. The solution of these equations expresses the electromagnetic field variables by the noise-current densities by means of Green's tensor of the macroscopic Maxwell equations. The explicit quantization is performed by means of the noise-current densities, whereby a diagonal Hamiltonian is introduced, which then guarantees the time development according to Maxwell's equation and the fulfillment of the fundamental simultaneous commutation relations of the field variables. In the case of the interaction of the medium-supported field with atoms the Hamiltonian must be extended by atom-field interactions energies, whereby the canonical coupling schemes of the minimal or multipolar coupling can be used. The dieelectric properties of the material bodies as well as their shape are coded in the Green tensor of the macroscopic Maxwell equations. As preparing step first the Green tensor was specified in order to derive three-dimensional input-output relations for the electromagnetic field operators on a plane multilayer structure. Such a general dewscription of the electromagnetic field allows the inclusion both of dispersion and absorption of the media and the

  6. Room Temperature Experiments with a Macroscopic Sapphire Mechanical Oscillator

    Science.gov (United States)

    Bourhill, Jeremy; Ivanov, Eugene; Tobar, Micahel

    2015-03-01

    We present initial results from a number of experiments conducted on a 0.53 kg sapphire ``dumbbell'' crystal. Mechanical motion of the crystal structure alters the dimensions of the crystal, and the induced strain changes the permittivity. These two effects frequency modulate resonant microwave whispering gallery modes, simultaneously excited within the crystal. A novel microwave readout system is described allowing extremely low noise measurements of this frequency modulation with a phase noise floor of -160 dBc/Hz at 100 kHz, near our modes of interest. Fine-tuning of the crystal's suspension have allowed for the optimisation of mechanical Q-factors in preparation for cryogenic experiments, with a value of 8 x 107 achieved so far. Finally, results are presented that demonstrate the excitation of mechanical modes via radiation pressure force. These are all important steps towards the overall goal of the experiment; to cool a macroscopic device to the quantum ground state.

  7. Macroscopic electromagnetic response of metamaterials with toroidal resonances

    CERN Document Server

    Savinov, V; Zheludev, N I

    2013-01-01

    Toroidal dipole, first described by Ia. B. Zeldovich [Sov. Phys. JETP 33, 1184 (1957)], is a distinct electromagnetic excitation that differs both from the electric and the magnetic dipoles. It has a number of intriguing properties: static toroidal nuclear dipole is responsible for parity violation in atomic spectra; interactions between static toroidal dipole and oscillating magnetic dipole are claimed to violate Newton's Third Law while non-stationary charge-current configurations involving toroidal multipoles have been predicted to produce vector potential in the absence of electromagnetic fields. Existence of the toroidal response in metamaterials was recently demonstrated and is now a growing field of research. However, no direct analytical link has yet been established between the transmission and reflection of macroscopic electromagnetic media and toroidal dipole excitations. To address this essential gap in electromagnetic theory we have developed an analytical approach linking microscopic and macrosc...

  8. Experiments testing macroscopic quantum superpositions must be slow

    CERN Document Server

    Mari, Andrea; Giovannetti, Vittorio

    2015-01-01

    We consider a thought experiment where the preparation of a macroscopically massive or charged particle in a quantum superposition and the associated dynamics of a distant test particle apparently allow for superluminal communication. We give a solution to the paradox which is based on the following fundamental principle: any local experiment, discriminating a coherent superposition from an incoherent statistical mixture, necessarily requires a minimum time proportional to the mass (or charge) of the system. For a charged particle, we consider two examples of such experiments, and show that they are both consistent with the previous limitation. In the first, the measurement requires to accelerate the charge, that can entangle with the emitted photons. In the second, the limitation can be ascribed to the quantum vacuum fluctuations of the electromagnetic field. On the other hand, when applied to massive particles our result provides an indirect evidence for the existence of gravitational vacuum fluctuations an...

  9. Macroscopic heat transport equations and heat waves in nonequilibrium states

    Science.gov (United States)

    Guo, Yangyu; Jou, David; Wang, Moran

    2017-03-01

    Heat transport may behave as wave propagation when the time scale of processes decreases to be comparable to or smaller than the relaxation time of heat carriers. In this work, a generalized heat transport equation including nonlinear, nonlocal and relaxation terms is proposed, which sums up the Cattaneo-Vernotte, dual-phase-lag and phonon hydrodynamic models as special cases. In the frame of this equation, the heat wave propagations are investigated systematically in nonequilibrium steady states, which were usually studied around equilibrium states. The phase (or front) speed of heat waves is obtained through a perturbation solution to the heat differential equation, and found to be intimately related to the nonlinear and nonlocal terms. Thus, potential heat wave experiments in nonequilibrium states are devised to measure the coefficients in the generalized equation, which may throw light on understanding the physical mechanisms and macroscopic modeling of nanoscale heat transport.

  10. Effect of inhibitors on macroscopical oxidation kinetics of calcium sulfite

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yi; WANG Li-dong; WANG Xiao-ming; LI Qiang-wei; XU Pei-yao

    2005-01-01

    In the presence of inhibitors, the macroscopical oxidation kinetics of calcium sulfite, the main byproduct in wet limestone scrubbing, was studied for the first time by adding different inhibitors and varying pH, concentration of calcium sulfite, oxygen partial pressure, concentration of inhibitors and temperature. The mathematical model about the general oxidation reaction was established,which was controlled by three steps involving dissolution of calcium sulfite, mass transfer of oxygen and chemical reaction in the solution.It was concluded that the general reaction was controlled by mass transfer of oxygen under uncatalyzed conditions, while it was controlled by dissolution of calcium sulfite after adding three kinds of inhibitors. Thus, the theory was provided for investigating the mechanism and oxidation kinetics of sulfite. The beneficial references were also supplied for design of oxidation technics in the wet limestone scrubbing.

  11. Elastic Enhancement Factor: from Mesoscopic Systems to Macroscopic Analogous Devices

    CERN Document Server

    Sokolov, Valentin V

    2014-01-01

    Excess of probabilities of the elastic processes over the inelastic ones is a common feature of the resonance phenomena, described in the framework of the random matrix theory. This phenomenon is quantitatively characterized by the elastic enhancement factor $F^{(\\beta)}$ that is a typical ratio of elastic and inelastic cross sections. Being measured experimentally, this quantity can supply us with information on the character of dynamics of the intermediate complicated open system. We discuss properties of the enhancement factor in a wide scope from mesoscopoic systems to macroscopic analogous devices and demonstrate essential qualitative distinction between the elastic enhancement factor's peculiarities in these two cases. Complete analytical solution is found for the case of systems without time-reversal symmetry and only a few open equivalent scattering channels.

  12. Macroscopic and direct light propulsion of bulk graphene material

    CERN Document Server

    Zhang, Tengfei; Wu, Yingpeng; Xiao, Peishuang; Yi, Ningbo; Lu, Yanhong; Ma, Yanfeng; Huang, Yi; Zhao, Kai; Yan, Xiao-Qing; Liu, Zhi-Bo; Tian, Jian-Guo; Chen, Yongsheng

    2015-01-01

    It has been a great challenge to achieve the direct light manipulation of matter on a bulk scale. In this work, the direct light propulsion of matter was observed on a macroscopic scale for the first time using a bulk graphene based material. The unique structure and properties of graphene and the morphology of the bulk graphene material make it capable of not only absorbing light at various wavelengths but also emitting energetic electrons efficiently enough to drive the bulk material following Newtonian mechanics. Thus, the unique photonic and electronic properties of individual graphene sheets are manifested in the response of the bulk state. These results offer an exciting opportunity to bring about bulk scale light manipulation with the potential to realize long-sought proposals in areas such as the solar sail and space transportation driven directly by sunlight.

  13. Macroscopic self-reorientation of interacting two-dimensional crystals.

    Science.gov (United States)

    Woods, C R; Withers, F; Zhu, M J; Cao, Y; Yu, G; Kozikov, A; Ben Shalom, M; Morozov, S V; van Wijk, M M; Fasolino, A; Katsnelson, M I; Watanabe, K; Taniguchi, T; Geim, A K; Mishchenko, A; Novoselov, K S

    2016-03-10

    Microelectromechanical systems, which can be moved or rotated with nanometre precision, already find applications in such fields as radio-frequency electronics, micro-attenuators, sensors and many others. Especially interesting are those which allow fine control over the motion on the atomic scale because of self-alignment mechanisms and forces acting on the atomic level. Such machines can produce well-controlled movements as a reaction to small changes of the external parameters. Here we demonstrate that, for the system of graphene on hexagonal boron nitride, the interplay between the van der Waals and elastic energies results in graphene mechanically self-rotating towards the hexagonal boron nitride crystallographic directions. Such rotation is macroscopic (for graphene flakes of tens of micrometres the tangential movement can be on hundreds of nanometres) and can be used for reproducible manufacturing of aligned van der Waals heterostructures.

  14. Macroscopic acousto-mechanical analogy of a microbubble

    CERN Document Server

    Chaline, Jennifer; Mehrem, Ahmed; Bouakaz, Ayache; Santos, Serge Dos; Sánchez-Morcillo, Víctor J

    2015-01-01

    Microbubbles, either in the form of free gas bubbles surrounded by a fluid or encapsulated bubbles used currently as contrast agents for medical echography, exhibit complex dynamics under specific acoustic excitations. Nonetheless, considering their micron size and the complexity of their interaction phenomenon with ultrasound waves, expensive and complex experiments and/or simulations are required for their analysis. The behavior of a microbubble along its equator can be linked to a system of coupled oscillators. In this study, the oscillatory behavior of a microbubble has been investigated through an acousto-mechanical analogy based on a ring-shaped chain of coupled pendula. Observation of parametric vibration modes of the pendula ring excited at frequencies between $1$ and $5$ Hz is presented. Simulations have been carried out and show mode mixing phenomena. The relevance of the analogy between a microbubble and the macroscopic acousto-mechanical setup is discussed and suggested as an alternative way to in...

  15. Combined macroscopic and microscopic detection of viral genes in tissues

    Energy Technology Data Exchange (ETDEWEB)

    Haase, A.T.; Gantz, D.; Blum, H.; Stowring, L.; Ventura, P.; Geballe, A.; Moyer, B.; Brahic, M.

    1985-01-15

    A hybridization technique has been devised for detecting and quantitating viral genes in tissues that combines macroscopic and microscopic analyses in the same section. The method is based on dual labeling virus-specific probes with /sup 125/I and /sup 35/S to generate signals that can be detected both with X-ray films and nuclear track emulsions. The regions of increased hybridization evident in the X-ray film serve as a guide to the portion of the section that warrants microscopic examination. Detection of viral RNA in tissues with Visna virus and viral DNA with hepatitis B virus are illustrated, and potential applications of this technique in virology and other disciplines are discussed.

  16. Innovating e-waste management: From macroscopic to microscopic scales.

    Science.gov (United States)

    Zeng, Xianlai; Yang, Congren; Chiang, Joseph F; Li, Jinhui

    2017-01-01

    Waste electrical and electronic equipment (WEEE or e-waste) has become a global problem, due to its potential environmental pollution and human health risk, and its containing valuable resources (e.g., metals, plastics). Recycling for e-waste will be a necessity, not only to address the shortage of mineral resources for electronics industry, but also to decline environmental pollution and human health risk. To systematically solve the e-waste problem, more attention of e-waste management should transfer from macroscopic to microscopic scales. E-waste processing technology should be significantly improved to diminish and even avoid toxic substance entering into downstream of material. The regulation or policy related to new production of hazardous substances in recycled materials should also be carried out on the agenda. All the findings can hopefully improve WEEE legislation for regulated countries and non-regulated countries.

  17. Witnessing Macroscopic Entanglement in a Staggered Magnetic Field

    CERN Document Server

    Hide, J; Son, W; Vedral, V; Hide, Jenny; Lawrie, Ian; Son, Wonmin; Vedral, Vlatko

    2007-01-01

    We investigate macroscopic entanglement in an infinite XX spin-1/2 chain with staggered magnetic field, $B_l=B+e^{-i\\pi l}b$. Using single-site entropy and by constructing an entanglement witness, we search for the existence of entanglement when the system is at absolute zero, as well as in thermal equilibrium. Although the role of the alternating magnetic field $b$ is, in general, to suppress entanglement as do $B$ and $T$, we find that when T=0, introducing $b$ allows the existence of entanglement even when the uniform magnetic field $B$ is arbitrarily large. We find that the region and the amount of entanglement in the spin chain can be enhanced by a staggered magnetic field.

  18. Microscopic and Macroscopic Simulation of Competition between Languages

    CERN Document Server

    Stauffer, D; Stauffer, Dietrich; Schulze, Christian

    2005-01-01

    The similarity of the evolution of human languages (or alphabets, bird songs, >...) to biological evolution of species is utilized to study with up to $10^9$ people the rise and fall of languages either by macroscopic differential equations similar to biological Lotka-Volterra equation, or by microscopic Monte Carlo simulations of bit-strings incorporating the birth, maturity, and death of every individual. For our bit-string model, depending on parameters either one language comprises the majority of speakers (dominance), or the population splits into many languages having in order of magnitude the same number of speakers (fragmentation); in the latter case the size distribution is log-normal, with upward deviations for small sizes, just as in reality for human languages. On a lattice two different dominating languages can coexist in neighbouring regions, without being favoured or disfavoured by different status. We deal with modifications and competition for existing languages, not with the evolution or lea...

  19. Dissipative Optomechanical Preparation of Macroscopic Quantum Superposition States

    Science.gov (United States)

    Abdi, M.; Degenfeld-Schonburg, P.; Sameti, M.; Navarrete-Benlloch, C.; Hartmann, M. J.

    2016-06-01

    The transition from quantum to classical physics remains an intensely debated question even though it has been investigated for more than a century. Further clarifications could be obtained by preparing macroscopic objects in spatial quantum superpositions and proposals for generating such states for nanomechanical devices either in a transient or a probabilistic fashion have been put forward. Here, we introduce a method to deterministically obtain spatial superpositions of arbitrary lifetime via dissipative state preparation. In our approach, we engineer a double-well potential for the motion of the mechanical element and drive it towards the ground state, which shows the desired spatial superposition, via optomechanical sideband cooling. We propose a specific implementation based on a superconducting circuit coupled to the mechanical motion of a lithium-decorated monolayer graphene sheet, introduce a method to verify the mechanical state by coupling it to a superconducting qubit, and discuss its prospects for testing collapse models for the quantum to classical transition.

  20. Anisotropic magnetothermopower in ferromagnetic thin films grown on macroscopic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Jayathilaka, P.B. [Department of Physical Sciences, Faculty of Applied Sciences, Rajarata University of Sri Lanka, Mihintale (Sri Lanka); Belyea, D.D. [Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Fawcett, T.J. [College of Engineering, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Miller, Casey W. [School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623 (United States)

    2015-05-15

    We report observing the anisotropic magnetothermopower in a variety of ferromagnetic thin films grown on macroscopic substrates. These measurements were enabled by eliminating spurious signals related to the Anomalous Nernst Effect by butt-mounting the sample to the heat source and sink, and appropriate positioning of electrical contacts to avoid unwanted thermal gradients. This protocol enabled detailed measurements of the magnetothermopower in the transverse and longitudinal configurations. This may enable Spin Seebeck Effect studies in the in-plane geometry. - Highlights: • Unintentional thermal gradients along surface normal mitigated via butt-mounting. • Longitudinal/transverse magnetothermopower measured on many systems. • Anomalous Nernst Effect reduced. • Importance of magnetic anisotropy identified with angle-dependent measurements.

  1. Macroscopic quantum electrodynamics of high-Q cavities

    Energy Technology Data Exchange (ETDEWEB)

    Khanbekyan, Mikayel

    2009-10-27

    In this thesis macroscopic quantum electrodynamics in linear media was applied in order to develop an universally valid quantum theory for the description of the interaction of the electromagnetic field with atomic sources in high-Q cavities. In this theory a complete description of the characteristics of the emitted radiation is given. The theory allows to show the limits of the applicability of the usually applied theory. In order to establish an as possible generally valid theory first the atom-field interaction was studied in the framework of macroscopic quantum electrodynamics in dispersive and absorptive media. In order to describe the electromagnetic field from Maxwell's equations was started, whereby the noise-current densities, which are connected with the absorption of the medium, were included. The solution of these equations expresses the electromagnetic field variables by the noise-current densities by means of Green's tensor of the macroscopic Maxwell equations. The explicit quantization is performed by means of the noise-current densities, whereby a diagonal Hamiltonian is introduced, which then guarantees the time development according to Maxwell's equation and the fulfillment of the fundamental simultaneous commutation relations of the field variables. In the case of the interaction of the medium-supported field with atoms the Hamiltonian must be extended by atom-field interactions energies, whereby the canonical coupling schemes of the minimal or multipolar coupling can be used. The dieelectric properties of the material bodies as well as their shape are coded in the Green tensor of the macroscopic Maxwell equations. As preparing step first the Green tensor was specified in order to derive three-dimensional input-output relations for the electromagnetic field operators on a plane multilayer structure. Such a general dewscription of the electromagnetic field allows the inclusion both of dispersion and absorption of the media and the

  2. Fault detection by surface seismic scanning tunneling macroscope: Field test

    KAUST Repository

    Hanafy, Sherif M.

    2014-08-05

    The seismic scanning tunneling macroscope (SSTM) is proposed for detecting the presence of near-surface impedance anomalies and faults. Results with synthetic data are consistent with theory in that scatterers closer to the surface provide brighter SSTM profiles than those that are deeper. The SSTM profiles show superresolution detection if the scatterers are in the near-field region of the recording line. The field data tests near Gulf of Aqaba, Haql, KSA clearly show the presence of the observable fault scarp, and identify the subsurface presence of the hidden faults indicated in the tomograms. Superresolution detection of the fault is achieved, even when the 35 Hz data are lowpass filtered to the 5-10 Hz band.

  3. Effects of varying interfacial surface tension on macroscopic polymer lenses

    Science.gov (United States)

    Zimmerman, Charlotte; White, Mason; Baylor, Martha-Elizabeth

    2015-09-01

    We investigate macroscopic polymer lenses (0.5- to 2.5-cm diameter) fabricated by dropping hydrophobic photocurable resin onto the surface of various hydrophilic liquid surfaces. Due to the intermolecular forces along the interface between the two liquids, a lens shape is formed. We find that we can vary the lens geometry by changing the region over which the resin is allowed to spread and the surface tension of the substrate to produce lenses with theoretically determined focal lengths ranging from 5 to 25 mm. These effects are varied by changing the container width, substrate composition, and substrate temperature. We present data for five different variants, demonstrating that we can control the lens dimensions for polymer lens applications that require high surface quality.

  4. Long-term creep properties of cementitious materials: Comparing microindentation testing with macroscopic uniaxial compressive testing

    OpenAIRE

    Zhang, Qing; Le Roy, Robert; VANDAMME, Mathieu; ZUBER, Bruno

    2014-01-01

    This study is dedicated to comparing minutes-long microindentation creep experiments on cement paste with years-long macroscopic creep experiments on concrete and months-long macroscopic creep experiments on cement paste. For all experiments, after a transient period the creep function was well captured by a logarithmic function of time, the amplitude of which is governed by a so-called creep modulus. The non-logarithmic transient periods lasted for days at the macroscopic scale, but only for...

  5. Treatment with the NK1 antagonist emend reduces blood brain barrier dysfunction and edema formation in an experimental model of brain tumors.

    Directory of Open Access Journals (Sweden)

    Elizabeth Harford-Wright

    Full Text Available The neuropeptide substance P (SP has been implicated in the disruption of the blood-brain barrier (BBB and development of cerebral edema in acute brain injury. Cerebral edema accumulates rapidly around brain tumors and has been linked to several tumor-associated deficits. Currently, the standard treatment for peritumoral edema is the corticosteroid dexamethasone, prolonged use of which is associated with a number of deleterious side effects. As SP is reported to increase in many cancer types, this study examined whether SP plays a role in the genesis of brain peritumoral edema. A-375 human melanoma cells were injected into the right striatum of male Balb/c nude mice to induce brain tumor growth, with culture medium injected in animals serving as controls. At 2, 3 or 4 weeks following tumor cell inoculation, non-treated animals were perfusion fixed for immunohistochemical detection of Albumin, SP and NK1 receptor. A further subgroup of animals was treated with a daily injection of the NK1 antagonist Emend (3 mg/kg, dexamethasone (8 mg/kg or saline vehicle at 3 weeks post-inoculation. Animals were sacrificed a week later to determine BBB permeability using Evan's Blue and brain water content. Non-treated animals demonstrated a significant increase in albumin, SP and NK1 receptor immunoreactivity in the peritumoral area as well as increased perivascular staining in the surrounding brain tissue. Brain water content and BBB permeability was significantly increased in tumor-inoculated animals when compared to controls (p<0.05. Treatment with Emend and dexamethasone reduced BBB permeability and brain water content when compared to vehicle-treated tumor-inoculated mice. The increase in peritumoral staining for both SP and the NK1 receptor, coupled with the reduction in brain water content and BBB permeability seen following treatment with the NK1 antagonist Emend, suggests that SP plays a role in the genesis of peritumoral edema, and thus warrants

  6. Wild-Type N-Ras, Overexpressed in Basal-like Breast Cancer, Promotes Tumor Formation by Inducing IL-8 Secretion via JAK2 Activation

    Directory of Open Access Journals (Sweden)

    Ze-Yi Zheng

    2015-07-01

    Full Text Available Basal-like breast cancers (BLBCs are aggressive, and their drivers are unclear. We have found that wild-type N-RAS is overexpressed in BLBCs but not in other breast cancer subtypes. Repressing N-RAS inhibits transformation and tumor growth, whereas overexpression enhances these processes even in preinvasive BLBC cells. We identified N-Ras-responsive genes, most of which encode chemokines; e.g., IL8. Expression levels of these chemokines and N-RAS in tumors correlate with outcome. N-Ras, but not K-Ras, induces IL-8 by binding and activating the cytoplasmic pool of JAK2; IL-8 then acts on both the cancer cells and stromal fibroblasts. Thus, BLBC progression is promoted by increasing activities of wild-type N-Ras, which mediates autocrine/paracrine signaling that can influence both cancer and stroma cells.

  7. Wild-Type N-Ras, Overexpressed in Basal-like Breast Cancer, Promotes Tumor Formation by Inducing IL-8 Secretion via JAK2 Activation.

    Science.gov (United States)

    Zheng, Ze-Yi; Tian, Lin; Bu, Wen; Fan, Cheng; Gao, Xia; Wang, Hai; Liao, Yi-Hua; Li, Yi; Lewis, Michael T; Edwards, Dean; Zwaka, Thomas P; Hilsenbeck, Susan G; Medina, Daniel; Perou, Charles M; Creighton, Chad J; Zhang, Xiang H-F; Chang, Eric C

    2015-07-21

    Basal-like breast cancers (BLBCs) are aggressive, and their drivers are unclear. We have found that wild-type N-RAS is overexpressed in BLBCs but not in other breast cancer subtypes. Repressing N-RAS inhibits transformation and tumor growth, whereas overexpression enhances these processes even in preinvasive BLBC cells. We identified N-Ras-responsive genes, most of which encode chemokines; e.g., IL8. Expression levels of these chemokines and N-RAS in tumors correlate with outcome. N-Ras, but not K-Ras, induces IL-8 by binding and activating the cytoplasmic pool of JAK2; IL-8 then acts on both the cancer cells and stromal fibroblasts. Thus, BLBC progression is promoted by increasing activities of wild-type N-Ras, which mediates autocrine/paracrine signaling that can influence both cancer and stroma cells.

  8. C. elegans DAF-16/FOXO interacts with TGF-ß/BMP signaling to induce germline tumor formation via mTORC1 activation.

    Directory of Open Access Journals (Sweden)

    Wenjing Qi

    2017-05-01

    Full Text Available Activation of the FOXO transcription factor DAF-16 by reduced insulin/IGF signaling (IIS is considered to be beneficial in C. elegans due to its ability to extend lifespan and to enhance stress resistance. In the germline, cell-autonomous DAF-16 activity prevents stem cell proliferation, thus acting tumor-suppressive. In contrast, hypodermal DAF-16 causes a tumorous germline phenotype characterized by hyperproliferation of the germline stem cells and rupture of the adjacent basement membrane. Here we show that cross-talk between DAF-16 and the transforming growth factor ß (TGFß/bone morphogenic protein (BMP signaling pathway causes germline hyperplasia and results in disruption of the basement membrane. In addition to activating MADM/NRBP/hpo-11 gene alone, DAF-16 also directly interacts with both R-SMAD proteins SMA-2 and SMA-3 in the nucleus to regulate the expression of mTORC1 pathway. Knocking-down of BMP genes or each of the four target genes in the hypodermis was sufficient to inhibit germline proliferation, indicating a cell-non-autonomously controlled regulation of stem cell proliferation by somatic tissues. We propose the existence of two antagonistic DAF-16/FOXO functions, a cell-proliferative somatic and an anti-proliferative germline activity. Whereas germline hyperplasia under reduced IIS is inhibited by DAF-16 cell-autonomously, activation of somatic DAF-16 in the presence of active IIS promotes germline proliferation and eventually induces tumor-like germline growth. In summary, our results suggest a novel pathway crosstalk of DAF-16 and TGF-ß/BMP that can modulate mTORC1 at the transcriptional level to cause stem-cell hyperproliferation. Such cell-type specific differences may help explaining why human FOXO activity is considered to be tumor-suppressive in most contexts, but may become oncogenic, e.g. in chronic and acute myeloid leukemia.

  9. Spatially- and temporally-controlled postnatal p53 knockdown cooperates with embryonic Schwann cell precursor Nf1 gene loss to promote malignant peripheral nerve sheath tumor formation.

    Science.gov (United States)

    Hirbe, Angela C; Dahiya, Sonika; Friedmann-Morvinski, Dinorah; Verma, Inder M; Clapp, D Wade; Gutmann, David H

    2016-02-16

    Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive sarcomas that arise sporadically or in association with the Neurofibromatosis type 1 (NF1) cancer predisposition syndrome. In individuals with NF1, MPNSTs are hypothesized to arise from Nf1-deficient Schwann cell precursor cells following the somatic acquisition of secondary cooperating genetic mutations (e.g., p53 loss). To model this sequential genetic cooperativity, we coupled somatic lentivirus-mediated p53 knockdown in the adult right sciatic nerve with embryonic Schwann cell precursor Nf1 gene inactivation in two different Nf1 conditional knockout mouse strains. Using this approach, ~60% of mice with Periostin-Cre-mediated Nf1 gene inactivation (Periostin-Cre; Nf1(flox/flox) mice) developed tumors classified as low-grade MPNSTs following p53 knockdown (mean, 6 months). Similarly, ~70% of Nf1+/- mice with GFAP-Cre-mediated Nf1 gene inactivation (GFAP-Cre; Nf1(flox/null) mice) developed low-grade MPNSTs following p53 knockdown (mean, 3 months). In addition, wild-type and Nf1+/- mice with GFAP-Cre-mediated Nf1 loss develop MPNSTs following somatic p53 knockout with different latencies, suggesting potential influences of Nf1+/- stromal cells in MPNST pathogenesis. Collectively, this new MPNST model system permits the analysis of somatically-acquired events as well as tumor microenvironment signals that potentially cooperate with Nf1 loss in the development and progression of this deadly malignancy.

  10. Functional hyper-IL-6 from vaccinia virus-colonized tumors triggers platelet formation and helps to alleviate toxicity of mitomycin C enhanced virus therapy

    Directory of Open Access Journals (Sweden)

    Sturm Julia B

    2012-01-01

    Full Text Available Abstract Background Combination of oncolytic vaccinia virus therapy with conventional chemotherapy has shown promise for tumor therapy. However, side effects of chemotherapy including thrombocytopenia, still remain problematic. Methods Here, we describe a novel approach to optimize combination therapy of oncolytic virus and chemotherapy utilizing virus-encoding hyper-IL-6, GLV-1h90, to reduce chemotherapy-associated side effects. Results We showed that the hyper-IL-6 cytokine was successfully produced by GLV-1h90 and was functional both in cell culture as well as in tumor-bearing animals, in which the cytokine-producing vaccinia virus strain was well tolerated. When combined with the chemotherapeutic mitomycin C, the anti-tumor effect of the oncolytic virotherapy was significantly enhanced. Moreover, hyper-IL-6 expression greatly reduced the time interval during which the mice suffered from chemotherapy-induced thrombocytopenia. Conclusion Therefore, future clinical application would benefit from careful investigation of additional cytokine treatment to reduce chemotherapy-induced side effects.

  11. S100A4-neutralizing antibody suppresses spontaneous tumor progression, pre-metastatic niche formation and alters T-cell polarization balance

    DEFF Research Database (Denmark)

    Grum-Schwensen, Birgitte; Klingelhöfer, Jörg; Beck, Mette

    2015-01-01

    the metastatic spread of tumor cells is the S100A4 protein. S100A4 is known as an inducer of inflammatory processes and has been shown to attract T-cells to the primary tumor and to the pre-metastatic niche. The present study aims to examine the immunomodulatory role of S100A4 in vivo and in vitro and assess...... the mode of action of 6B12, a S100A4 neutralizing antibody. METHODS: The therapeutic effect of the 6B12 antibody was evaluated in two different mouse models. First, in a model of spontaneous breast cancer we assessed the dynamics of tumor growth and metastasis. Second, in a model of metastatic niche...... that the S100A4 protein alters the expression of transcription factor and signal transduction pathway genes involved in the T-cell lineage differentiation. T-cells challenged with S100A4 demonstrated reduced proportion of Th1-polarized cells shifting the Th1/Th2 balance towards the Th2 pro...

  12. Wilms Tumor

    Science.gov (United States)

    ... Wilms tumor is 1 pound at diagnosis. Some children also may have nausea, stomach pain, high blood pressure (hypertension), blood in the urine, loss of appetite, or fever. Even though Wilms tumors often are ...

  13. Hypothalamic tumor

    Science.gov (United States)

    Complications of brain surgery may include: Bleeding Brain damage Death (rarely) Infection Seizures can result from the tumor or from any surgical procedure on the brain. Hydrocephalus can occur with some tumors and ...

  14. Inducing the Formation of Functional Macroscopic Assemblies Through Programmed Orthogonal Supramolecular Interactions

    Science.gov (United States)

    2014-05-27

    journal references, in the following categories: (b) Papers published in non-peer-reviewed journals (N/A for none) Fusion Functional Polymeric Materials...Division of Polymeric Materials: Science and Engineering (PMSE) Young Investigator Award 2014 Names of Post Doctorates Names of Faculty Supported Names of...diketopyrrolopyrrole (DPP), and electron acceptors based on the perylene derived bisimide (PDI) scaffolds were chosen because of their easy preparation and their

  15. Urogenital tumors

    Energy Technology Data Exchange (ETDEWEB)

    Weller, R.E.

    1994-03-01

    An overview is provided for veterinary care of urogenital tumors in companion animals, especially the dog. Neoplasms discussed include tumors of the kidney, urinary bladder, prostate, testis, ovary, vagina, vulva and the canine transmissible venereal tumor. Topics addressed include description, diagnosis and treatment.

  16. Brain Tumors

    Science.gov (United States)

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  17. Odontogenic Tumors

    OpenAIRE

    TAHSİNOĞLU, Melih

    2013-01-01

    DefinitionThe neoplasms that consist of the cells considered specialized for odontogenesis, and their product (dentin, enamel, cementum) are called odontogenic tumors.ClassificationTo initiate odontogenesis, epithelium is a must. Same rule holds for the odontogenic tumors: without odontogenic epithelium, odontogenic tumors cannot be, without the induction of odontogenic epithelium odontogenic mesenchyme cannot develop.

  18. Macroscopically aligned molecular stacking structures in mesogenic phthalocyanine derivative films fabricated by heated spin-coating method

    Energy Technology Data Exchange (ETDEWEB)

    Higashi, Takuya; Fiderana Ramananarivo, Mihary; Ohmori, Masashi; Yoshida, Hiroyuki; Fujii, Akihiko, E-mail: afujii@opal.eei.eng.osaka-u.ac.jp; Ozaki, Masanori

    2015-11-02

    Spin-coated films of a mesogenic phthalocyanine derivative, 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH{sub 2}), with macroscopic alignment of molecular stacking structure were obtained by processing in liquid-crystal phase of C6PcH{sub 2}. The column axis direction of the hexagonal columnar structure of C6PcH{sub 2} was determined by microscopic observation and polarized optical absorption measurement and was uniform in the millimeter-scale area. Highly ordered molecular stacking structure in the film, which is similar to the single crystal, was clarified by measurement of molecular tilting angle with respect to the column axis. The origin of the macroscopic molecular alignment during film formation was investigated by taking the process-temperature-dependent properties of the films into consideration. - Highlights: • We fabricated mesogenic phthalocyanine films by heated spin-coating method. • The maximum domain size was obtained by fabricating at mesogenic-phase temperature. • The optic axis direction in the film was uniform in the millimeter-scale area. • The crystalline structure in the film was similar to that of the single crystal. • The effects of mesogenic phase during the formation on the molecular alignment were presumed.

  19. HFC-134a refrigerant gas hydrate formation process and RIN model

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, the macroscopic visualization experiments of HFC-134a refrigerant gas hydrate formation are investigated. According to the macroscopic photos and Mori's microscopic photos of HFC-134a hydrate formation process, the mechanism of gas hydrate formation is analyzed.A random inducement nucleation model is presented to describe the hydrate formation process. The factors affecting the fractal growth dimension in the model, such as step,branch increment and angle, are discussed.``

  20. Secondary ovarian tumors: Evaluation of 44 cases

    Directory of Open Access Journals (Sweden)

    Sevgiye KAÇAR ÖZKARA

    2007-09-01

    Full Text Available Secondary ovarian tumors compose 3-8% of all, and 10-30% of malignant ovarian tumors. Histopathological features of SOT diagnosed in our department in 10-year period are discussed. Macroscopical, microscopical, immunohistochemical and cytopathological features of secondary ovarian tumors diagnosed between 1997- 2006 were re-evaluated. Additional histochemical and immunohistochemical studies were applied to find the primaries. Data was statistically evaluated. Totally, 44 secondary ovarian tumors had been diagnosed within this period. The mean age of the patients was 52.9 years; the mean tumor diameter was 103.7 mm.The primary was gastrointestinal system in 50% of the cases. Ten of them (22.7% were metastases of signet ring cell carcinoma of stomach (Kruckenberg tumor while 9 cases (20.5% were from colorectal and three (6.8% were from appendiceal adenocarcinomas. 27.3% of our cases were originated from genital tract. Synchronous endometrioid adenocarcinomas of corpus uteri and ovary were seen in six cases (13.6%. Ovarian involvement of serous carcinomas of corpus uteri was seen in five (11.4% cases. Ovarian metastases of breast carcinoma in four cases (9.1% were seen while the ovarian involvement of adrenal cortical and tubal carcinomas was observed in one case, each. The primary was peritoneal surface in five (11.4% of the cases. Tumors were bilateral in 65.9% of the cases, and there was statistically significant correlation between the bilaterality rate of the tumors and the primary (p=0.015.The more precise diagnosis of secondary ovarian tumors could be reached by evaluation of clinical, surgical, macroscopical, microscopical, cytopathological and immunohistochemical findings together.

  1. A nuclear localization signal and the C-terminal omega sequence in the Agrobacterium tumefaciens VirD2 endonuclease are important for tumor formation.

    OpenAIRE

    Shurvinton, C. E.; Hodges, L; Ream, W

    1992-01-01

    The T-DNA portion of the Agrobacterium tumefaciens tumor-inducing (Ti) plasmid integrates into plant nuclear DNA. Direct repeats define the T-DNA ends; transfer begins when the VirD2 endonuclease produces a site-specific nick in the right-hand border repeat and attaches to the 5' end of the nicked strand. Subsequent events generate linear single-stranded VirD2-bound DNA molecules that include the entire T-DNA (T-strands). VirD2 protein contains a nuclear localization signal (NLS) near the C t...

  2. The Unique Macroscopic Appearance of Gouty Arthritis of the Knee.

    Science.gov (United States)

    Mittl, Gregory S; Zuckerman, Joseph D

    2015-07-01

    Patients with significant gouty arthritis can develop disabling joint pain secondary to monosodium urate (MSU) articular deposition. We report a case of white, chalky MSU crystal deposition covering the articular surfaces of the knee as discovered by total knee arthroplasty. A 65-year-old male with a history of gout presented with bilateral knee pain. His radiographic imaging was negative for gouty tophi, and he elected to undergo left total knee arthroplasty. Intraoperatively a distinct chalky, white paste consistent with MSU deposition was observed covering the articular surfaces of the knee consistent with the diagnosis of gouty arthritis. Gout is the most common inflammatory arthritis affecting more than 3 million people in the USA. The inflammation results from the phagocytosis of monosodium urate crystals (MSU) and the release of inflammatory cytokines within the joint. Gout progresses from acute to chronic over many years and frequently causes chronic arthropathy. When significant knee pain and disability is associated with gouty arthropathy, total knee arthroplasty is certainly an option. The pathological appearance of gouty joints is characteristic. Macroscopic examination of joints affected by gout reveals a nodular, white, chalky appearance. Polarized microscopy of gout demonstrates negative birefringent needle-shaped MSU crystals. In this case report, we describe the characteristic chalky, white MSU deposit that covers the articular surfaces of a knee joint in a patient with a history of gout undergoing total knee arthroplasty. The investigators have obtained the patient's informed written consent for print and electronic publication of the case report.

  3. A macroscopic crowd motion model of gradient flow type

    CERN Document Server

    Maury, Bertrand; Santambrogio, Filippo

    2010-01-01

    A simple model to handle the flow of people in emergency evacuation situations is considered: at every point x, the velocity U(x) that individuals at x would like to realize is given. Yet, the incompressibility constraint prevents this velocity field to be realized and the actual velocity is the projection of the desired one onto the set of admissible velocities. Instead of looking at a microscopic setting (where individuals are represented by rigid discs), here the macroscopic approach is investigated, where the unknwon is the evolution of the density . If a gradient structure is given, say U is the opposite of the gradient of D where D is, for instance, the distance to the exit door, the problem is presented as a Gradient Flow in the Wasserstein space of probability measures. The functional which gives the Gradient Flow is neither finitely valued (since it takes into account the constraints on the density), nor geodesically convex, which requires for an ad-hoc study of the convergence of a discrete scheme.

  4. Macroscopic Dynamical Description of Rotating au + au System

    Science.gov (United States)

    Cârjan, N.; Siwek-Wilczyńska, K.; Skwira-Chalot, I.; Wilczyński, J.

    Events with more than two heavy fragments have been abundantly observed in heavy-ion semi-peripheral (fission-like) reaction 197Au+197Au at 15 MeV/nucleon. This raised interesting questions about their origin and about the time-scale at which they occur. As a possible explanation of this process, the surface instability of the cylindrical neck that is formed along the path from contact to reseparation of the rotating Au+Au system is investigated in the present paper. For this purpose the Los Alamos finite-range macroscopic dynamical model was used. The calculations were performed at relatively high angular momenta, L = 100 to 300 ħ, for two types of dissipation mechanisms: two-body viscosity and one-body dissipation. Various initial nuclear deformations and initial kinetic energies in the fission direction were considered. The resulting dynamical evolution in the multidimensional deformation space always led to multifragment scission configurations suggesting that ternary and quaternary break-up can occur during the heavy-ion reaction studied.

  5. Feedback Gating Control for Network Based on Macroscopic Fundamental Diagram

    Directory of Open Access Journals (Sweden)

    YangBeibei Ji

    2016-01-01

    Full Text Available Empirical data from Yokohama, Japan, showed that a macroscopic fundamental diagram (MFD of urban traffic provides for different network regions a unimodal low-scatter relationship between network vehicle density and network space-mean flow. This provides new tools for network congestion control. Based on MFD, this paper proposed a feedback gating control policy which can be used to mitigate network congestion by adjusting signal timings of gating intersections. The objective of the feedback gating control model is to maximize the outflow and distribute the allowed inflows properly according to external demand and capacity of each gating intersection. An example network is used to test the performance of proposed feedback gating control model. Two types of background signalization types for the intersections within the test network, fixed-time and actuated control, are considered. The results of extensive simulation validate that the proposed feedback gating control model can get a Pareto improvement since the performance of both gating intersections and the whole network can be improved significantly especially under heavy demand situations. The inflows and outflows can be improved to a higher level, and the delay and queue length at all gating intersections are decreased dramatically.

  6. The assembly of C. elegans lamins into macroscopic fibers.

    Science.gov (United States)

    Zingerman-Koladko, Irena; Khayat, Maayan; Harapin, Jan; Shoseyov, Oded; Gruenbaum, Yosef; Salman, Ahmad; Medalia, Ohad; Ben-Harush, Kfir

    2016-10-01

    Intermediate filament (IF) proteins are known mainly by their propensity to form viscoelastic filamentous networks within cells. In addition, IF-proteins are essential parts of various biological materials, such as horn and hagfish slime threads, which exhibit a range of mechanical properties from hard to elastic. These properties and their self-assembly nature made IF-proteins attractive building blocks for biomimetic and biological materials in diverse applications. Here we show that a type V IF-protein, the Caenorhabditis elegans nuclear lamin (Ce-lamin), is a promising building block for protein-based fibers. Electron cryo-tomography of vitrified sections enabled us to depict the higher ordered assembly of the Ce-lamin into macroscopic fibers through the creation of paracrystalline fibers, which are prominent in vitro structures of lamins. The lamin fibers respond to tensile force as other IF-protein-based fibers, i.e., hagfish slime threads, and possess unique mechanical properties that may potentially be used in certain applications. The self-assembly nature of lamin proteins into a filamentous structure, which is further assembled into a complex network, can be easily modulated. This knowledge may lead to a better understanding of the relationship in IF-proteins-based fibers and materials, between their hierarchical structures and their mechanical properties.

  7. Scattering of acoustic waves by macroscopically inhomogeneous poroelastic tubes.

    Science.gov (United States)

    Groby, J-P; Dazel, O; Depollier, C; Ogam, E; Kelders, L

    2012-07-01

    Wave propagation in macroscopically inhomogeneous porous materials has received much attention in recent years. For planar configurations, the wave equation, derived from the alternative formulation of Biot's theory of 1962, was reduced and solved recently: first in the case of rigid frame inhomogeneous porous materials and then in the case of inhomogeneous poroelastic materials in the framework of Biot's theory. This paper focuses on the solution of the full wave equation in cylindrical coordinates for poroelastic tubes in which the acoustic and elastic properties of the poroelastic tube vary in the radial direction. The reflection coefficient is obtained numerically using the state vector (or the so-called Stroh) formalism and Peano series. This coefficient can then be used to straightforwardly calculate the scattered field. To validate the method of resolution, results obtained by the present method are compared to those calculated by the classical transfer matrix method in the case of a two-layer poroelastic tube. As an example, a long bone excited in the sagittal plane is considered. Finally, a discussion is given of ultrasonic time domain scattered field for various inhomogeneity profiles, which could lead to the prospect of long bone characterization.

  8. Macroscopic effects of the spectral structure in turbulent flows

    Science.gov (United States)

    Tran, T.; Chakraborty, P.; Guttenberg, N.; Prescott, A.; Kellay, H.; Goldburg, W.; Goldenfeld, N.; Gioia, G.

    2010-11-01

    There is a missing link between macroscopic properties of turbulent flows, such as the frictional drag of a wall-bounded flow, and the turbulent spectrum. To seek the missing link we carry out unprecedented experimental measurements of the frictional drag in turbulent soap-film flows over smooth walls. These flows are effectively two-dimensional, and we are able to create soap-film flows with the two types of turbulent spectrum that are theoretically possible in two dimensions: the "enstrophy cascade," for which the spectral exponent α= 3, and the "inverse energy cascade," for which the spectral exponent α= 5/3. We find that the functional relation between the frictional drag f and the Reynolds number Re depends on the spectral exponent: where α= 3, f ˜Re-1/2; where α= 5/3, f ˜Re-1/4. Each of these scalings may be predicted from the attendant value of α by using a recently proposed spectral theory of the frictional drag. In this theory the frictional drag of turbulent flows on smooth walls is predicted to be f ˜Re^(1-α)/(1+α).

  9. Properties of nuclear matter from macroscopic-microscopic mass formulas

    Science.gov (United States)

    Wang, Ning; Liu, Min; Ou, Li; Zhang, Yingxun

    2015-12-01

    Based on the standard Skyrme energy density functionals together with the extended Thomas-Fermi approach, the properties of symmetric and asymmetric nuclear matter represented in two macroscopic-microscopic mass formulas: Lublin-Strasbourg nuclear drop energy (LSD) formula and Weizsäcker-Skyrme (WS*) formula, are extracted through matching the energy per particle of finite nuclei. For LSD and WS*, the obtained incompressibility coefficients of symmetric nuclear matter are K∞ = 230 ± 11 MeV and 235 ± 11 MeV, respectively. The slope parameter of symmetry energy at saturation density is L = 41.6 ± 7.6 MeV for LSD and 51.5 ± 9.6 MeV for WS*, respectively, which is compatible with the liquid-drop analysis of Lattimer and Lim [4]. The density dependence of the mean-field isoscalar and isovector effective mass, and the neutron-proton effective masses splitting for neutron matter are simultaneously investigated. The results are generally consistent with those from the Skyrme Hartree-Fock-Bogoliubov calculations and nucleon optical potentials, and the standard deviations are large and increase rapidly with density. A better constraint for the effective mass is helpful to reduce uncertainties of the depth of the mean-field potential.

  10. Tunable Broadband Transparency of Macroscopic Quantum Superconducting Metamaterials

    Directory of Open Access Journals (Sweden)

    Daimeng Zhang

    2015-12-01

    Full Text Available Narrow-band invisibility in an otherwise opaque medium has been achieved by electromagnetically induced transparency (EIT in atomic systems. The quantum EIT behavior can be classically mimicked by specially engineered metamaterials via carefully controlled interference with a “dark mode.” However, the narrow transparency window limits the potential applications that require a tunable wideband transparent performance. Here, we present a macroscopic quantum superconducting metamaterial with manipulative self-induced broadband transparency due to a qualitatively novel nonlinear mechanism that is different from conventional EIT or its classical analogs. A near-complete disappearance of resonant absorption under a range of applied rf flux is observed experimentally and explained theoretically. The transparency comes from the intrinsic bistability of the meta-atoms and can be tuned on and off easily by altering rf and dc magnetic fields, temperature, and history. Hysteretic in situ 100% tunability of transparency paves the way for autocloaking metamaterials, intensity-dependent filters, and fast-tunable power limiters.

  11. Towards a macroscopic modeling of the complexity in traffic flow.

    Science.gov (United States)

    Rosswog, Stephan; Wagner, Peter

    2002-03-01

    Based on the assumption of a safe velocity U(e)(rho) depending on the vehicle density rho, a macroscopic model for traffic flow is presented that extends the model of the Kühne-Kerner-Konhäuser by an interaction term containing the second derivative of U(e)(rho). We explore two qualitatively different forms of U(e): a conventional Fermi-type function and, motivated by recent experimental findings, a function that exhibits a plateau at intermediate densities, i.e., in this density regime the exact distance to the car ahead is only of minor importance. To solve the fluid-like equations a Lagrangian particle scheme is developed. The suggested model shows a much richer dynamical behavior than the usual fluid-like models. A large variety of encountered effects is known from traffic observations, many of which are usually assigned to the elusive state of "synchronized flow." Furthermore, the model displays alternating regimes of stability and instability at intermediate densities. It can explain data scatter in the fundamental diagram and complicated jam patterns. Within this model, a consistent interpretation of the emergence of very different traffic phenomena is offered: they are determined by the velocity relaxation time, i.e., the time needed to relax towards U(e)(rho). This relaxation time is a measure of the average acceleration capability and can be attributed to the composition (e.g., the percentage of trucks) of the traffic flow.

  12. Zero time tunneling: macroscopic experiments with virtual particles

    Directory of Open Access Journals (Sweden)

    Nimtz Günter

    2015-01-01

    Full Text Available Feynman introduced virtual particles in his diagrams as intermediate states of an interaction process. They represent necessary intermediate states between observable real states. Such virtual particles were introduced to describe the interaction process between an electron and a positron and for much more complicated interaction processes. Other candidates for virtual particles are evanescent modes in optics and in elastic fields. Evanescent modes have a purely imaginary wave number, they represent the mathematical analogy of the tunneling solutions of the Schrödinger equation. Evanescent modes exist in the forbidden frequency bands of a photonic lattice and in undersized wave guides, for instance. The most prominent example for the occurrence of evanescent modes is the frustrated total internal reflection (FTIR at double prisms. Evanescent modes and tunneling lie outside the bounds of the special theory of relativity. They can cause faster than light (FTL signal velocities. We present examples of the quantum mechanical behavior of evanescent photons and phonons at a macroscopic scale. The evanescent modes of photons are described by virtual particles as predicted by former QED calculations.

  13. Macroscopic strain controlled ion current in an elastomeric microchannel

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Chin-Chang; Nguyen, Du; Buchsbaum, Steven; Innes, Laura; Dennin, Michael, E-mail: mdennin@uci.edu [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Li, Yongxue [Department of Civil and Environmental Engineering, University of California, Irvine, California 92697 (United States); Esser-Kahn, Aaron P. [Department of Chemistry, University of California, Irvine, California 92697 (United States); Valdevit, Lorenzo [Department of Mechanical and Aerospace Engineering, University of California, Irvine, California 92697-3975 (United States); Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Sun, Lizhi [Department of Civil and Environmental Engineering, University of California, Irvine, California 92697 (United States); Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Siwy, Zuzanna [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Department of Chemistry, University of California, Irvine, California 92697 (United States)

    2015-05-07

    We report on the fabrication of an ultra-high aspect ratio ionically conductive single microchannel with tunable diameter from ≈ 20 μm to fully closed. The 4 mm-long channel is fabricated in a Polydimethylsiloxane (PDMS) mold and its cross-sectional area is controlled by applying macroscopic compressive strain to the mold in a direction perpendicular to the channel length. We investigated the ionic conduction properties of the channel. For a wide range of compressive strain up to ≈ 0.27, the strain dependence of the resistance is monotonic and fully reversible. For strain > 0.27, ionic conduction suddenly shuts off and the system becomes hysteretic (whereby a finite strain reduction is required to reopen the channel). Upon unloading, the original behavior is retrieved. This reversible behavior is observed over 200 compression cycles. The cross-sectional area of the channel can be inferred from the ion current measurement, as confirmed by a Nano-Computed Tomography investigation. We show that the cross-sectional area decreases monotonically with the applied compressive strain in the reversible range, in qualitative agreement with linear elasticity theory. We find that the shut-off strain is affected by the spatial extent of the applied strain, which provides additional tunability. Our tunable channel is well-suited for multiple applications in micro/nano-fluidic devices.

  14. Experiments testing macroscopic quantum superpositions must be slow

    Science.gov (United States)

    Mari, Andrea; de Palma, Giacomo; Giovannetti, Vittorio

    2016-03-01

    We consider a thought experiment where the preparation of a macroscopically massive or charged particle in a quantum superposition and the associated dynamics of a distant test particle apparently allow for superluminal communication. We give a solution to the paradox which is based on the following fundamental principle: any local experiment, discriminating a coherent superposition from an incoherent statistical mixture, necessarily requires a minimum time proportional to the mass (or charge) of the system. For a charged particle, we consider two examples of such experiments, and show that they are both consistent with the previous limitation. In the first, the measurement requires to accelerate the charge, that can entangle with the emitted photons. In the second, the limitation can be ascribed to the quantum vacuum fluctuations of the electromagnetic field. On the other hand, when applied to massive particles our result provides an indirect evidence for the existence of gravitational vacuum fluctuations and for the possibility of entangling a particle with quantum gravitational radiation.

  15. LETTERS AND COMMENTS: Adiabatic process reversibility: microscopic and macroscopic views

    Science.gov (United States)

    Anacleto, Joaquim; Pereira, Mário G.

    2009-05-01

    The reversibility of adiabatic processes was recently addressed by two publications. In the first (Miranda 2008 Eur. J. Phys. 29 937-43), an equation was derived relating the initial and final volumes and temperatures for adiabatic expansions of an ideal gas, using a microscopic approach. In that relation the parameter r accounts for the process reversibility, ranging between 0 and 1, which corresponds to the free and reversible expansion, respectively. In the second (Anacleto and Pereira 2009 Eur. J. Phys. 30 177-83), the authors have shown that thermodynamics can effectively and efficiently be used to obtain the general law for adiabatic processes carried out by an ideal gas, including compressions, for which r \\ge 1. The present work integrates and extends the aforementioned studies, providing thus further insights into the analysis of the adiabatic process. It is shown that Miranda's work is wholly valid for compressions. In addition, it is demonstrated that the adiabatic reversibility coefficient given in terms of the piston velocity and the root mean square velocity of the gas particles is equivalent to the macroscopic description, given just by the quotient between surroundings and system pressure values.

  16. Single-file diffusion of macroscopic charged particles.

    Science.gov (United States)

    Coste, C; Delfau, J-B; Even, C; Saint Jean, M

    2010-05-01

    In this paper, we study a macroscopic system of electrically interacting metallic beads organized as a sequence along an annulus. A random mechanical shaking mimics the thermal excitation. We exhibit non-Fickian diffusion (single-file diffusion) at large time. We measure the mobility of the particles and compare it to theoretical expectations. We show that our system cannot be accurately described by theories assuming only hard-sphere interactions. Its behavior is qualitatively described by a theory extended to more realistic potentials [M. Kollmann, Phys. Rev. Lett. 90, 180602 (2003)]. A correct quantitative agreement is shown and we interpret the discrepancies by the violation of the assumption of overdamped dynamics, which is a key point in the theory. We recast previous results on colloids with known interaction potentials and compare them quantitatively to the theory. Focusing on the transition between ordinary and single-file diffusions, we exhibit a dimensionless crossover time that is of order 1 both for colloids and our system, although the time and length scales differ by several orders of magnitude.

  17. Quantum-limited heat conduction over macroscopic distances

    Science.gov (United States)

    Partanen, Matti; Tan, Kuan Yen; Govenius, Joonas; Lake, Russell E.; Mäkelä, Miika K.; Tanttu, Tuomo; Möttönen, Mikko

    2016-05-01

    The emerging quantum technological apparatuses, such as the quantum computer, call for extreme performance in thermal engineering. Cold distant heat sinks are needed for the quantized electric degrees of freedom owing to the increasing packaging density and heat dissipation. Importantly, quantum mechanics sets a fundamental upper limit for the flow of information and heat, which is quantified by the quantum of thermal conductance. However, the short distance between the heat-exchanging bodies in the previous experiments hinders their applicability in quantum technology. Here, we present experimental observations of quantum-limited heat conduction over macroscopic distances extending to a metre. We achieved this improvement of four orders of magnitude in the distance by utilizing microwave photons travelling in superconducting transmission lines. Thus, it seems that quantum-limited heat conduction has no fundamental distance cutoff. This work establishes the integration of normal-metal components into the framework of circuit quantum electrodynamics, which provides a basis for the superconducting quantum computer. Especially, our results facilitate remote cooling of nanoelectronic devices using faraway in situ-tunable heat sinks. Furthermore, quantum-limited heat conduction is important in contemporary thermodynamics. Here, the long distance may lead to ultimately efficient mesoscopic heat engines with promising practical applications.

  18. Semiconductor spintronics in a participating phonon medium: Macroscopic equations

    Directory of Open Access Journals (Sweden)

    A. Rossani

    2013-09-01

    Full Text Available In the last two decades considerable interest has arisen on the spin related phenomena in semiconductor devices. In semiconductor materials two essential mechanisms act on the spin dynamics: the spin-orbit coupling and the spin-flip interactions. Here the novelty is that we adopt the asymptotic approach developed in previous papers of mine [A. Rossani, Physica A 305, 323 (2002; A. Rossani, G. Spiga, and A. Domaingo, J. Phys. A 36, 11955 (2003; A. Rossani and G. Spiga, J. Math. Phys. 47, 013301 (2006; A. Rossani and A. M. Scarfone, Physica B 334, 292 (2003; A. Rossani, J. Phys. A 43, 165002 (2010]. The aim of this paper is to derive macroscopic equations starting from a kinetic approach. Moreover an equation for the evolution of the spin density is added, which account for a general dispersion relation. The treatment of spin-flip processes, derived from first principles, is new and leads to an explicit expression of the relaxation time as a function of the temperature.

  19. Properties of nuclear matter from macroscopic-microscopic mass formulas

    CERN Document Server

    Wang, Ning; Ou, Li; Zhang, Yingxun

    2015-01-01

    Based on the standard Skyrme energy density functionals together with the extended Thomas-Fermi approach, the properties of symmetric and asymmetric nuclear matter represented in two macroscopic-microscopic mass formulas: Lublin-Strasbourg nuclear drop energy (LSD) formula and Weizs\\"acker-Skyrme (WS*) formula, are extracted through matching the energy per particle of finite nuclei. For LSD and WS*, the obtained incompressibility coefficients of symmetric nuclear matter are $K_\\infty=230 \\pm 11$ MeV and $235\\pm 11$ MeV, respectively. The slope parameter of symmetry energy at saturation density is $L=41.6\\pm 7.6$ MeV for LSD and $51.5\\pm 9.6$ MeV for WS*, respectively, which is compatible with the liquid-drop analysis of Lattimer and Lim [ApJ. \\textbf{771}, 51 (2013)]. The density dependence of the mean-field isoscalar and isovector effective mass, and the neutron-proton effective masses splitting for neutron matter are simultaneously investigated. The results are generally consistent with those from the Skyrm...

  20. Theory and feasibility tests for a seismic scanning tunnelling macroscope

    KAUST Repository

    Schuster, Gerard T.

    2012-09-01

    We propose a seismic scanning tunnelling macroscope (SSTM) that can detect subwavelength scatterers in the near-field of either the source or the receivers. Analytic formulas for the time reverse mirror (TRM) profile associated with a single scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the scatterer is in the near-field region. This means that, as the scatterer approaches the source, imaging of the scatterer with super-resolution can be achieved. Acoustic and elastic simulations support this concept, and a seismic experiment in an Arizona tunnel shows a TRM profile with super-resolution adjacent to the fault location. The SSTM is analogous to the optical scanning tunnelling microscopes having subwavelength resolution. Scaled to seismic frequencies, it is theoretically possible to extract 100 Hz information from 20 Hz data by the imaging of near-field seismic energy.

  1. Direct Observation of Spatial Quantum Correlations in the Macroscopic Regime

    CERN Document Server

    Kumar, Ashok; Marino, A M

    2016-01-01

    Spatial quantum correlations in the transverse degree of freedom promise to enhance optical resolution, image detection, and quantum communications through parallel quantum information encoding. In particular, the ability to observe these spatial quantum correlations in a single shot will enable such enhancements in applications that require real time imaging, such as particle tracking and in-situ imaging of atomic systems. Here, we report on the direct measurement of spatial quantum correlations in the macroscopic regime in single images using an electron-multiplying charge-coupled device camera. A four-wave mixing process in hot rubidium atoms is used to generate narrowband-bright-entangled pulsed twin-beams of light with $\\sim10^8$ photons in each beam. Owing to momentum conservation in this process, the twin-beams are momentum correlated, which leads to spatial quantum correlations in far field. We show around 2 dB of spatial quantum noise reduction with respect to the shot noise limit. The spatial squeez...

  2. Peroxisome Proliferator-Activated Receptor γ Expression Is Inversely Associated with Macroscopic Vascular Invasion in Human Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Hui-Tzu Hsu

    2016-07-01

    Full Text Available Peroxisome proliferator-activated receptor γ (PPARγ is a ligand-activated nuclear receptor that regulates cellular lipid and glucose metabolism and also plays an inhibitory role in various cancers. However, the role of PPARγ in hepatocellular carcinoma (HCC remains controversial. This study aimed to investigate the prognostic value of PPARγ in HCC and its role in inhibiting tumor progression, namely, HCC cell growth, migration, and angiogenesis. Immunohistochemical PPARγ staining was examined in 83 HCC specimens to investigate the clinicopathological correlations between PPARγ expression and various parameters. The functional role of PPARγ was determined via PPARγ overexpression and knockdown in HCC cells. Patients with low HCC tissue PPARγ expression were significantly younger (p = 0.006, and exhibited more tumor numbers (p = 0.038, more macroscopic vascular invasion (MVI (p = 0.008, and more advanced TNM (size of primary tumor, number of regional lymph nodes, and distant metastasis stages at diagnosis (p = 0.013 than patients with high HCC tissue PPARγ expression. PPARγ knockdown increased HCC cell growth, migration, and angiogenesis, while PPARγ overexpression reduced HCC cell growth, migration, and angiogenesis. These results suggest that low PPARγ expression is an independent predictor of more MVI in HCC patients. PPARγ contributes to the suppression of HCC cell growth, migration, and angiogenesis. Therefore, PPARγ may be a therapeutic target in HCC patients.

  3. Grasping the Second Law of Thermodynamics at University: The Consistency of Macroscopic and Microscopic Explanations

    Science.gov (United States)

    Leinonen, Risto; Asikainen, Mervi A.; Hirvonen, Pekka E.

    2015-01-01

    This study concentrates on evaluating the consistency of upper-division students' use of the second law of thermodynamics at macroscopic and microscopic levels. Data were collected by means of a paper and pencil test (N = 48) focusing on the macroscopic and microscopic features of the second law concerned with heat transfer processes. The data…

  4. Grasping the Second Law of Thermodynamics at University: The Consistency of Macroscopic and Microscopic Explanations

    Science.gov (United States)

    Leinonen, Risto; Asikainen, Mervi A.; Hirvonen, Pekka E.

    2015-01-01

    This study concentrates on evaluating the consistency of upper-division students' use of the second law of thermodynamics at macroscopic and microscopic levels. Data were collected by means of a paper and pencil test (N = 48) focusing on the macroscopic and microscopic features of the second law concerned with heat transfer processes. The data…

  5. A Model for Macroscopic Quantum Tunneling of Bose-Einstein Condensate with Attractive Interaction

    Institute of Scientific and Technical Information of China (English)

    YAN Ke-Zhu; TAN Wei-Han

    2000-01-01

    Based on the numerical wave function solutions of neutral atoms with attractive interaction in a harmonic trap, we propose an exactly solvable model for macroscopic quantum tunneling of a Bose condensate with attractive interaction. We calculate the rate of macroscopic quantum tunneling from a metastable condensate state to the collapse state and analyze the stability of the attractive Bose-Einstein condensation.

  6. Effect of particle friction and polydispersity on the macroscopic stress–strain relations of granular materials

    NARCIS (Netherlands)

    Göncü, F.; Luding, S.

    2013-01-01

    The macroscopic mechanical behavior of granular materials inherently depends on the properties of particles that compose them. Using the discrete element method, the effect of particle contact friction and polydispersity on the macroscopic stress response of 3D sphere packings is studied. The analyt

  7. A nuclear localization signal and the C-terminal omega sequence in the Agrobacterium tumefaciens VirD2 endonuclease are important for tumor formation.

    Science.gov (United States)

    Shurvinton, C E; Hodges, L; Ream, W

    1992-12-15

    The T-DNA portion of the Agrobacterium tumefaciens tumor-inducing (Ti) plasmid integrates into plant nuclear DNA. Direct repeats define the T-DNA ends; transfer begins when the VirD2 endonuclease produces a site-specific nick in the right-hand border repeat and attaches to the 5' end of the nicked strand. Subsequent events generate linear single-stranded VirD2-bound DNA molecules that include the entire T-DNA (T-strands). VirD2 protein contains a nuclear localization signal (NLS) near the C terminus and may direct bound T-strands to plant nuclei. We constructed mutations in virD2 and showed that the NLS was important for tumorigenesis, although T-strand production occurred normally in its absence. A tobacco etch virus NLS, substituted for the VirD2 NLS, restored tumor-inducing activity. Amino acids (the omega sequence) at the C terminus of VirD2, outside the NLS and the endonuclease domain, contributed significantly to tumorigenesis, suggesting that VirD2 may serve a third important function in T-DNA transfer.

  8. Macroscopic realism, wave-particle duality and the superposition principle for entangled states

    CERN Document Server

    Chuprikov, N L

    2006-01-01

    On the basis of our model of a one-dimensional (1D) completed scattering (Russian Physics, 49, p.119 and p.314 (2006)) we argue that the linear formalism of quantum mechanics (QM) respects the principles of the macroscopic realism (J. Phys.: Condens. Matter, 14, R415-R451 (2002)). In QM one has to distinguish two kinds of pure ensembles: pure unentangled ensembles to be macroscopically inseparable, and pure entangled ones to be macroscopically separable. A pure entangled ensemble is an intermediate link between a pure unentangled ensemble and classical mixture. Like the former it strictly respects the linear formalism of QM. Like the latter it is decomposable into macroscopically distinct subensembles, in spite of interference between them; our new model exemplifies how to perform such a decomposition in the case of a 1D completed scattering. To respect macroscopic realism, the superposition principle must be reformulated: it must forbid introducing observables for entangled states.

  9. Angiogenesis and tumor

    Directory of Open Access Journals (Sweden)

    Kamran Mansouri

    2010-12-01

    Full Text Available Angiogenesis, the process of new blood vessel formation from existing ones, plays an important role in the physiologic circumstances such as embryonic development, placenta formation, and wound healing. It is also crucial to progress of pathogenic processes of a variety of disorders, including tumor growth and metastasis. In general, angiogenesis process is a multi-factorial and highly structured sequence of cellular events comprising migration, proliferation and differentiation of endothelial cells and finally vascular formation, maturation and remodeling.Thereby, angiogenesis inhibition as a helping agent to conventional therapies such as chemotherapy and radiation has attracted the scientists’ attentions studying in this field.

  10. SIRT1, Is It a Tumor Promoter or Tumor Suppressor?

    Directory of Open Access Journals (Sweden)

    Chu-Xia Deng

    2009-01-01

    Full Text Available SIRT1 has been considered as a tumor promoter because of its increased expression in some types of cancers and its role in inactivating proteins that are involved in tumor suppression and DNA damage repair. However, recent studies demonstrated that SIRT1 levels are reduced in some other types of cancers, and that SIRT1 deficiency results in genetic instability and tumorigenesis, while overexpression of SIRT1 attenuates cancer formation in mice heterozygous for tumor suppressor p53 or APC. Here, I review these recent findings and discuss the possibility that activation of SIRT1 both extends lifespan and inhibits cancer formation.

  11. Nonclassical interactions portrait in a macroscopic pedestrian flow model

    Science.gov (United States)

    Rosini, Massimiliano D.

    In this paper we describe the main characteristics of the macroscopic model for pedestrian flows introduced in [R.M. Colombo, M.D. Rosini, Pedestrian flows and non-classical shocks, Math. Methods Appl. Sci. 28 (13) (2005) 1553-1567] and recently sperimentally verified in [D. Helbing, A. Johansson, H.Z. Al-Abideen, Dynamics of crowd disasters: An empirical study, Phys. Rev. E (Statistical, Nonlinear, and Soft Matter Physics) 75 (4) (2007) 046109]. After a detailed study of all the possible wave interactions, we prove the existence of a weighted total variation that does not increase after any interaction. This is the main ingredient used in [R.M. Colombo, M.D. Rosini, Existence of nonclassical Cauchy problem modeling pedestrian flows, technical report, Brescia Department of Mathematics, 2008] to tackle the Cauchy problem through wave front tracking, see [A. Bressan, Hyperbolic Systems of Conservation Laws. The One-Dimensional Cauchy Problem, Oxford Lecture Ser. Math. Appl., vol. 20, Oxford Univ. Press, Oxford, 2000, The one-dimensional Cauchy problem; A. Bressan, The front tracking method for systems of conservation laws, in: C.M. Dafermos, E. Feireisl (Eds.), Handbook of Differential Equations; Evolutionary Equations, vol. 1, Elsevier, 2004, pp. 87-168; R.M. Colombo, Wave front tracking in systems of conservation laws, Appl. Math. 49 (6) (2004) 501-537]. From the mathematical point of view, this model is one of the few examples of conservation laws in which nonclassical solutions have a physical motivation, see [P.G. Lefloch, Hyperbolic Systems of Conservation Laws, Lectures Math. ETH Zürich, Birkhäuser, Basel, 2002, The theory of classical and nonclassical shock waves], and an existence result is available.

  12. Nuclear magnetic resonance studies of macroscopic morphology and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Barrall, Geoffrey Alden [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1995-09-01

    Nuclear magnetic resonance techniques are traditionally used to study molecular level structure and dynamics with a noted exception in medically applied NMR imaging (MRI). In this work, new experimental methods and theory are presented relevant to the study of macroscopic morphology and dynamics using NMR field gradient techniques and solid state two-dimensional exchange NMR. The goal in this work is not to take some particular system and study it in great detail, rather it is to show the utility of a number of new and novel techniques using ideal systems primarily as a proof of principle. By taking advantage of the analogy between NMR imaging and diffraction, one may simplify the experiments necessary for characterizing the statistical properties of the sample morphology. For a sample composed of many small features, e.g. a porous medium, the NMR diffraction techniques take advantage of both the narrow spatial range and spatial isotropy of the sample`s density autocorrelation function to obtain high resolution structural information in considerably less time than that required by conventional NMR imaging approaches. The time savings of the technique indicates that NMR diffraction is capable of finer spatial resolution than conventional NMR imaging techniques. Radio frequency NMR imaging with a coaxial resonator represents the first use of cylindrically symmetric field gradients in imaging. The apparatus as built has achieved resolution at the micron level for water samples, and has the potential to be very useful in the imaging of circularly symmetric systems. The study of displacement probability densities in flow through a random porous medium has revealed the presence of features related to the interconnectedness of the void volumes. The pulsed gradient techniques used have proven successful at measuring flow properties for time and length scales considerably shorter than those studied by more conventional techniques.

  13. Macroscopic behavior and microscopic magnetic properties of nanocarbon

    Energy Technology Data Exchange (ETDEWEB)

    Lähderanta, E., E-mail: Erkki.Lahderanta@lut.fi [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Ryzhov, V.A. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Petersburg Nuclear Physics Institute, NRC “Kurchatov Institute”, Orlova Coppice, Gatchina, Leningrad province 188300 (Russian Federation); Lashkul, A.V. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Galimov, D.M. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); South Ural State University, 454080 Chelyabinsk (Russian Federation); Titkov, A.N. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); A. F. Ioffe Physico-Technical Institute, 194021 St. Petersburg (Russian Federation); Matveev, V.V. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Saint-Petersburg State University, Saint-Petersburg 198504 (Russian Federation); Mokeev, M.V. [Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg (Russian Federation); Kurbakov, A.I. [Petersburg Nuclear Physics Institute, NRC “Kurchatov Institute”, Orlova Coppice, Gatchina, Leningrad province 188300 (Russian Federation); Lisunov, K.G. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Institute of Applied Physics ASM, Academiei Str., 5, MD 2028 Kishinev (Moldova, Republic of)

    2015-06-01

    Here are presented investigations of powder and glass-like samples containing carbon nanoparticles, not intentionally doped and doped with Ag, Au and Co. The neutron diffraction study reveals an amorphous structure of the samples doped with Au and Co, as well as the magnetic scattering due to a long-range FM order in the Co-doped sample. The composition and molecular structure of the sample doped with Au is clarified with the NMR investigations. The temperature dependence of the magnetization, M (T), exhibits large irreversibility in low fields of B=1–7 mT. M (B) saturates already above 2 T at high temperatures, but deviates from the saturation behavior below ~50 (150 K). Magnetic hysteresis is observed already at 300 K and exhibits a power-law temperature decay of the coercive field, B{sub c} (T). The macroscopic behavior above is typical of an assembly of partially blocked magnetic nanoparticles. The values of the saturation magnetization, M{sub s}, and the blocking temperature, T{sub b}, are obtained as well. However, the hysteresis loop in the Co-doped sample differs from that in other samples, and the values of B{sub c} and M{sub s} are noticeably increased. - Highlights: • We have investigated powder and glassy samples with carbon nanoparticles. • They include an undoped sample and those doped with Ag, Au and Co. • Neutron diffraction study reveals amorphous structure of Au- and Co-doped samples. • Composition and molecular structure of Au-doped sample was investigated with NMR. • Magnetic behavior is typical of an assembly of partially blocked magnetic nanoparticles.

  14. Proton irradiation effects on beryllium - A macroscopic assessment

    Science.gov (United States)

    Simos, Nikolaos; Elbakhshwan, Mohamed; Zhong, Zhong; Camino, Fernando

    2016-10-01

    Beryllium, due to its excellent neutron multiplication and moderation properties, in conjunction with its good thermal properties, is under consideration for use as plasma facing material in fusion reactors and as a very effective neutron reflector in fission reactors. While it is characterized by unique combination of structural, chemical, atomic number, and neutron absorption cross section it suffers, however, from irradiation generated transmutation gases such as helium and tritium which exhibit low solubility leading to supersaturation of the Be matrix and tend to precipitate into bubbles that coalesce and induce swelling and embrittlement thus degrading the metal and limiting its lifetime. Utilization of beryllium as a pion production low-Z target in high power proton accelerators has been sought both for its low Z and good thermal properties in an effort to mitigate thermos-mechanical shock that is expected to be induced under the multi-MW power demand. To assess irradiation-induced changes in the thermal and mechanical properties of Beryllium, a study focusing on proton irradiation damage effects has been undertaken using 200 MeV protons from the Brookhaven National Laboratory Linac and followed by a multi-faceted post-irradiation analysis that included the thermal and volumetric stability of irradiated beryllium, the stress-strain behavior and its ductility loss as a function of proton fluence and the effects of proton irradiation on the microstructure using synchrotron X-ray diffraction. The mimicking of high temperature irradiation of Beryllium via high temperature annealing schemes has been conducted as part of the post-irradiation study. This paper focuses on the thermal stability and mechanical property changes of the proton irradiated beryllium and presents results of the macroscopic property changes of Beryllium deduced from thermal and mechanical tests.

  15. Kaposi's sarcoma-associated herpesvirus-positive primary effusion lymphoma tumor formation in NOD/SCID mice is inhibited by neomycin and neamine blocking angiogenin's nuclear translocation.

    Science.gov (United States)

    Bottero, Virginie; Sadagopan, Sathish; Johnson, Karen E; Dutta, Sujoy; Veettil, Mohanan Valiya; Chandran, Bala

    2013-11-01

    Angiogenin (ANG) is a 14-kDa multifunctional proangiogenic secreted protein whose expression level correlates with the aggressiveness of several tumors. We observed increased ANG expression and secretion in endothelial cells during de novo infection with Kaposi's sarcoma-associated herpesvirus (KSHV), in cells expressing only latency-associated nuclear antigen 1 (LANA-1) protein, and in KSHV latently infected primary effusion lymphoma (PEL) BCBL-1 and BC-3 cells. Inhibition of phospholipase Cγ (PLCγ) mediated ANG's nuclear translocation by neomycin, an aminoglycoside antibiotic (not G418-neomicin), resulted in reduced KSHV latent gene expression, increased lytic gene expression, and increased cell death of KSHV(+) PEL and endothelial cells. ANG detection in significant levels in KS and PEL lesions highlights its importance in KSHV pathogenesis. To assess the in vivo antitumor activity of neomycin and neamine (a nontoxic derivative of neomycin), BCBL-1 cells were injected intraperitoneally into NOD/SCID mice. We observed significant extended survival of mice treated with neomycin or neamine. Markers of lymphoma establishment, such as increases in animal body weight, spleen size, tumor cell spleen infiltration, and ascites volume, were observed in nontreated animals and were significantly diminished by neomycin or neamine treatments. A significant decrease in LANA-1 expression, an increase in lytic gene expression, and an increase in cleaved caspase-3 were also observed in neomycin- or neamine-treated animal ascitic cells. These studies demonstrated that ANG played an essential role in KSHV latency maintenance and BCBL-1 cell survival in vivo, and targeting ANG function by neomycin/neamine to induce the apoptosis of cells latently infected with KSHV is an attractive therapeutic strategy against KSHV-associated malignancies.

  16. Slug inhibits the proliferation and tumor formation of human cervical cancer cells by up-regulating the p21/p27 proteins and down-regulating the activity of the Wnt/β-catenin signaling pathway via the trans-suppression Akt1/p-Akt1 expression

    Science.gov (United States)

    Cui, Nan; Yang, Wen-Ting; Zheng, Peng-Sheng

    2016-01-01

    Slug (Snai2) has been demonstrated to act as an oncogene or tumor suppressor in different human cancers, but the function of Slug in cervical cancer remains poorly understood. In this study, we demonstrated that Slug could suppress the proliferation of cervical cancer cells in vitro and tumor formation in vivo. Further experiments found that Slug could trans-suppress the expression of Akt1/p-Akt1 by binding to E-box motifs in the promoter of the Akt1 gene and then inhibit the cell proliferation and tumor formation of cervical cancer cells by up-regulating p21/p27 and/or down-regulating the activity of the Wnt/β-catenin signaling pathway. Therefore, Slug acts as a tumor suppressor during cervical carcinogenesis. PMID:27036045

  17. Structuring of metal-organic frameworks at the mesoscopic/macroscopic scale.

    Science.gov (United States)

    Furukawa, Shuhei; Reboul, Julien; Diring, Stéphane; Sumida, Kenji; Kitagawa, Susumu

    2014-08-21

    The assembly of metal ions with organic ligands through the formation of coordination bonds gives crystalline framework materials, known as metal-organic frameworks (MOFs), which recently emerged as a new class of porous materials. Besides the structural designability of MOFs at the molecular length scale, the researchers in this field very recently made important advances in creating more complex architectures at the mesoscopic/macroscopic scale, in which MOF nanocrystals are used as building units to construct higher-order superstructures. The structuring of MOFs in such a hierarchical order certainly opens a new opportunity to improve the material performance via design of the physical form rather than altering the chemical component. This review highlights these superstructures and their applications by categorizing them into four dimensionalities, zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) superstructures. Because the key issue for structuring of MOFs is to spatially control the nucleation process in desired locations, this review conceptually categorizes the available synthetic methodologies from the viewpoint of the reaction system.

  18. Sorption of selenium(VI) onto anatase: Macroscopic and microscopic characterization

    Science.gov (United States)

    Jordan, N.; Foerstendorf, H.; Weiß, S.; Heim, K.; Schild, D.; Brendler, V.

    2011-03-01

    The sorption of selenium(VI) onto pure anatase, a polymorph of titanium dioxide, was investigated. At the macroscopic level, batch experiments and electrophoretic mobility measurements were performed. Selenium(VI) retention was found to be pH-dependent, i.e. sorption of selenium(VI) decreases with increasing pH (pH range 3.5-11). Selenium(VI) sorption dependence on the ionic strength was also evidenced, i.e. sorption increases while the ionic strength decreases. Electrophoretic mobility measurements showed that selenium(VI) sorption had no effect on the isoelectric point of anatase. At the microscopic level, XPS (X-ray Photoelectron Spectroscopy) measurements evidenced the absence of reduction of selenium(VI) during the sorption process. Furthermore, the nature of the sorbed surface species at the anatase/liquid interface was elucidated using Attenuated Total Reflection Fourier-Transform Infrared (ATR FT-IR) spectroscopy. The spectroscopic results strongly suggested the formation of outer-sphere complexes on the whole pH range, in agreement with batch sorption experiments and electrophoretic mobility findings.

  19. chinmo is a functional effector of the JAK/STAT pathway that regulates eye development, tumor formation and stem cell self-renewal in Drosophila

    Science.gov (United States)

    Flaherty, Maria Sol; Salis, Pauline; Evans, Cory J.; Ekas, Laura A.; Marouf, Amine; Zavadil, Jiri; Banerjee, Utpal; Bach, Erika A.

    2010-01-01

    SUMMARY The Drosophila STAT transcription factor Stat92E regulates diverse functions, including organ development and stem cell self-renewal. However, the Stat92E functional effectors that mediate these processes are largely unknown. Here we show that chinmo is a cell-autonomous, downstream mediator of Stat92E that shares numerous functions with this protein. Loss of either gene results in malformed eyes and head capsules due to defects in eye progenitor cells. Hyperactivation of Stat92E or misexpression of Chinmo results in blood cell tumors. Both proteins are expressed in germline (GSCs) and cyst stem cells (CySCs) in the testis. While Stat92E is required for the self-renewal of both populations, chinmo is only required in CySCs, indicating that Stat92E regulates self-renewal in different stem cells through independent effectors. Like hyperactivated Stat92E, Chinmo misexpression in CySCs is sufficient to maintain GSCs non-autonomously. Chinmo is therefore a key effector of JAK/STAT signaling in a variety of developmental and pathological contexts. PMID:20412771

  20. Studies into the averaging problem: Macroscopic gravity and precision cosmology

    Science.gov (United States)

    Wijenayake, Tharake S.

    2016-08-01

    With the tremendous improvement in the precision of available astrophysical data in the recent past, it becomes increasingly important to examine some of the underlying assumptions behind the standard model of cosmology and take into consideration nonlinear and relativistic corrections which may affect it at percent precision level. Due to its mathematical rigor and fully covariant and exact nature, Zalaletdinov's macroscopic gravity (MG) is arguably one of the most promising frameworks to explore nonlinearities due to inhomogeneities in the real Universe. We study the application of MG to precision cosmology, focusing on developing a self-consistent cosmology model built on the averaging framework that adequately describes the large-scale Universe and can be used to study real data sets. We first implement an algorithmic procedure using computer algebra systems to explore new exact solutions to the MG field equations. After validating the process with an existing isotropic solution, we derive a new homogeneous, anisotropic and exact solution. Next, we use the simplest (and currently only) solvable homogeneous and isotropic model of MG and obtain an observable function for cosmological expansion using some reasonable assumptions on light propagation. We find that the principal modification to the angular diameter distance is through the change in the expansion history. We then linearize the MG field equations and derive a framework that contains large-scale structure, but the small scale inhomogeneities have been smoothed out and encapsulated into an additional cosmological parameter representing the averaging effect. We derive an expression for the evolution of the density contrast and peculiar velocities and integrate them to study the growth rate of large-scale structure. We find that increasing the magnitude of the averaging term leads to enhanced growth at late times. Thus, for the same matter content, the growth rate of large scale structure in the MG model

  1. Investigating the mechanics of earthquakes using macroscopic seismic parameters

    Science.gov (United States)

    Venkataraman, Anupama

    2002-09-01

    To understand the physics of earthquake rupture mechanics, we have to relate seismologically observable parameters to the dynamics of faulting. One of the key seismological parameters that will help us achieve this objective is the energy radiated by seismic waves. In this work, we develop a new method of estimating radiated energy from regional data using an empirical Green's function method; we also modify existing methods of estimating radiated energy from teleseismic data by improving the corrections applied to the observed seismic data for attenuation and directivity effects. We compute teleseismic estimates of radiated energy for 23 large subduction zone earthquakes recorded between 1992 and 2001; most of these earthquakes have a magnitude Mw > 7.5, but we also include some smaller (Mw ˜ 6.7) well-studied subduction zone earthquakes and 6 crustal earthquakes. We compile the static stress drop estimates for these 29 earthquakes from published literature. We then determine radiation efficiency of these earthquakes using a stress relaxation model that relates measurable and macroscopic seismological parameters to the physical processes on the fault zone via fracture energy. We also determine the rupture velocity of these earthquakes from published literature. A comparison of radiation efficiencies and rupture velocities of these earthquakes with the expected theoretical values for different modes crack propagation validates the use of the stress relaxation model to understand earthquake rupture mechanics. From our calculations, we observe that most earthquakes have radiation efficiencies between 0.25 and 1 and are hence efficient in generating seismic waves, but tsunami earthquakes and two deep earthquakes, the 1994 deep earthquake that occurred in Bolivia and the 1999 Russia-China border earthquake, have very small radiation efficiencies (<0.25) and hence dissipate a large amount of energy on the fault plane. We suggest that the difference in the radiation

  2. Macroscopic coherent structures in a stochastic neural network: from interface dynamics to coarse-grained bifurcation analysis.

    Science.gov (United States)

    Avitable, Daniele; Wedgwood, Kyle C A

    2017-02-01

    We study coarse pattern formation in a cellular automaton modelling a spatially-extended stochastic neural network. The model, originally proposed by Gong and Robinson (Phys Rev E 85(5):055,101(R), 2012), is known to support stationary and travelling bumps of localised activity. We pose the model on a ring and study the existence and stability of these patterns in various limits using a combination of analytical and numerical techniques. In a purely deterministic version of the model, posed on a continuum, we construct bumps and travelling waves analytically using standard interface methods from neural field theory. In a stochastic version with Heaviside firing rate, we construct approximate analytical probability mass functions associated with bumps and travelling waves. In the full stochastic model posed on a discrete lattice, where a coarse analytic description is unavailable, we compute patterns and their linear stability using equation-free methods. The lifting procedure used in the coarse time-stepper is informed by the analysis in the deterministic and stochastic limits. In all settings, we identify the synaptic profile as a mesoscopic variable, and the width of the corresponding activity set as a macroscopic variable. Stationary and travelling bumps have similar meso- and macroscopic profiles, but different microscopic structure, hence we propose lifting operators which use microscopic motifs to disambiguate them. We provide numerical evidence that waves are supported by a combination of high synaptic gain and long refractory times, while meandering bumps are elicited by short refractory times.

  3. Formation and stabilization of the telomeric antiparallel G-quadruplex and inhibition of telomerase by novel benzothioxanthene derivatives with anti-tumor activity

    Science.gov (United States)

    Zhang, Wen; Chen, Min; Ling Wu, Yan; Tanaka, Yoshimasa; Juan Ji, Yan; Lin Zhang, Su; He Wei, Chuan; Xu, Yan

    2015-09-01

    G-quadruplexes formed in telomeric DNA sequences at human chromosome ends can be a novel target for the development of therapeutics for the treatment of cancer patients. Herein, we examined the ability of six novel benzothioxanthene derivatives S1-S6 to induce the formation of and stabilize an antiparallel G-quadruplex by EMSA, UV-melting and CD techniques and the influence of S1-S6 on A549 and SGC7901 cells through real-time cell analysis, wound healing, trap assay methods. Results show that six compounds could differentially induce 26 nt G-rich oligonucleotides to form the G-quadruplex with high selectivity vs C-rich DNA, mutated DNA and double-stranded DNA, stabilize it with high affinity, promote apoptosis and inhibit mobility and telomerase activity of A549 cells and SGC7901 cells. Especially, S1, S3, S4 displayed stronger abilities, of which S3 was the most optimal with the maximum ΔTm value being up to 29.8 °C for G-quadruplex, the minimum IC50 value being 0.53 μM and the maximum cell inhibitory rate being up to 97.2%. This study suggests that this type of compounds that induce the formation of and stabilize the telomeric antiparallel G-quadruplex, and consequently inhibit telomerase activity, leading to cell apoptosis, can be screened for the discovery of novel antitumor therapeutics.

  4. Pindborg tumor

    Science.gov (United States)

    Caliaperoumal, Santhosh Kumar; Gowri, S.; Dinakar, J.

    2016-01-01

    Calcifying epithelial odontogenic tumor (CEOT), also known as Pindborg tumor, is a rare odontogenic epithelial neoplasm. So far, nearly 200 cases have been reported in the literature. We are reporting a case of CEOT in a 42-year-old male patient with painless bony swelling in the mandible. The clinical, radiographic, and histopathologic features are discussed with relevant references. PMID:27041911

  5. Pindborg tumor

    Directory of Open Access Journals (Sweden)

    Santhosh Kumar Caliaperoumal

    2016-01-01

    Full Text Available Calcifying epithelial odontogenic tumor (CEOT, also known as Pindborg tumor, is a rare odontogenic epithelial neoplasm. So far, nearly 200 cases have been reported in the literature. We are reporting a case of CEOT in a 42-year-old male patient with painless bony swelling in the mandible. The clinical, radiographic, and histopathologic features are discussed with relevant references.

  6. Three-Dimensional Reconstruction of Macroscopic Features in Biological Materials

    Science.gov (United States)

    Krumnikl, Michal; Sojka, Eduard; Gaura, Jan; Motyka, Oldřich

    This paper covers the topic of three dimensional reconstruction of small textureless formations usually found in biological samples. Generally used reconstructing algorithms do not provide sufficient accuracy for surface analysis. In order to achieve better results, combined strategy was developed, linking stereo matching algorithms with monocular depth cues such as depth from focus and depth from illumination.

  7. [About a case of calcifying fibrous tumor of the pleura].

    Science.gov (United States)

    Rocas, Delphine; Thivolet-Béjui, Françoise; Tronc, François; Chalabreysse, Lara

    2015-12-01

    Calcifying fibrous tumor is a rare soft tissue benign tumor (OMS 2002). Some pleural localisations are described, which affect slightly older individuals than the other soft tissue forms. The calcifying fibrous tumor is included in the 2004 World Health Organization classification of pleural tumors. A pleural tumor located in the right inferior pulmonary lobe is diagnosed in a 59-year-old man. This pleural tumor is macroscopically well-circumscribed. Histologically, the rare spindle tumoral cells are located between bundles of a collagenous tissue, sometimes hyalinized, with psammomatous or dystrophic calcifications. The tumoral cells have a fibrohistiocytic origin. They stain positively for antibodies against vimentin, factor XIIIa, CD68, CD163, CD34. Antibodies against smooth muscle actin, desmin, PS100, ALK1 and EBV are negative. Main differencial diagnoses are other benign pleural tumors (solitary fibrous tumor, inflammatory myofibroblastique tumor), some malignant tumors (desmoplastic malignant pleural mesothelioma) and pleural pseudotumors (calcified pleural plaques, chronic fibrous pleuritis, amylose, hyalinizing granuloma). Our case is the 15th pleural calcifying fibrous tumor being reported. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  8. Three-dimensional Fe3O4-graphene macroscopic composites for arsenic and arsenate removal.

    Science.gov (United States)

    Guo, Liangqia; Ye, Peirong; Wang, Jing; Fu, Fengfu; Wu, Zujian

    2015-11-15

    3D graphene macroscopic gel synthesized via self-assembly of GO nanosheets under basic conditions at low temperature is modified with polydopamine and Fe3O4 nanoparticles. The modification of polydopamine can not only strengthen the 3D graphene-based macroscopic architecture but also enhance the loadage and binding ability of Fe3O4 nanoparticles. The synthesized 3D Fe3O4-graphene macroscopic composites are characterized by SEM, XRD, XPS, BET, Raman and magnetic property and used as a versatile adsorbent for sub-ppm concentration of As(III) and As(V) removal from aqueous solutions. The experimental results suggest that the synthesized 3D Fe3O4-graphene macroscopic composites are promising for treating low concentration of arsenic contaminated water. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Hydrodynamic description of (visco)elastic composite materials and relative strains as a new macroscopic variable

    CERN Document Server

    Menzel, Andreas M

    2016-01-01

    One possibility to adjust material properties to a specific need is to embed units of one substance into a matrix of another substance. Even materials that are readily tunable during operation can be generated in this way. In (visco)elastic substances, both the matrix material as well as the inclusions and/or their immediate environment can be dynamically deformed. If the typical dynamic response time of the inclusions and their surroundings approach the macroscopic response time, their deformation processes need to be included into a dynamic macroscopic characterization. Along these lines, we present a hydrodynamic description of (visco)elastic composite materials. For this purpose, additional strain variables reflect the state of the inclusions and their immediate environment. These additional strain variables in general are not set by a coarse-grained macroscopic displacement field. Apart from that, during our derivation, we also include the macroscopic variables of relative translations and relative rotat...

  10. Generating giant and tunable nonlinearity in a macroscopic mechanical resonator from a single chemical bond

    Science.gov (United States)

    Huang, Pu; Zhou, Jingwei; Zhang, Liang; Hou, Dong; Lin, Shaochun; Deng, Wen; Meng, Chao; Duan, Changkui; Ju, Chenyong; Zheng, Xiao; Xue, Fei; Du, Jiangfeng

    2016-05-01

    Nonlinearity in macroscopic mechanical systems may lead to abundant phenomena for fundamental studies and potential applications. However, it is difficult to generate nonlinearity due to the fact that macroscopic mechanical systems follow Hooke's law and respond linearly to external force, unless strong drive is used. Here we propose and experimentally realize high cubic nonlinear response in a macroscopic mechanical system by exploring the anharmonicity in chemical bonding interactions. We demonstrate the high tunability of nonlinear response by precisely controlling the chemical bonding interaction, and realize, at the single-bond limit, a cubic elastic constant of 1 × 1020 N m-3. This enables us to observe the resonator's vibrational bi-states transitions driven by the weak Brownian thermal noise at 6 K. This method can be flexibly applied to a variety of mechanical systems to improve nonlinear responses, and can be used, with further improvements, to explore macroscopic quantum mechanics.

  11. Fractal Dimension and Universality in Avascular Tumor Growth

    CERN Document Server

    Ribeiro, Fabiano L; Mata, Angélica S

    2016-01-01

    The comprehension of tumor growth is a intriguing subject for scientists. New researches has been constantly required to better understand the complexity of this phenomenon. In this paper, we pursue a physical description that account for some experimental facts involving avascular tumor growth. We have proposed an explanation of some phenomenological (macroscopic) aspects of tumor, as the spatial form and the way it growths, from a individual-level (microscopic) formulation. The model proposed here is based on a simple principle: competitive interaction between the cells dependent on their mutual distances. As a result, we reproduce many empirical evidences observed in real tumors, as exponential growth in their early stages followed by a power law growth. The model also reproduces the fractal space distribution of tumor cells and the universal behavior presented in animals and tumor growth, conform reported by West, Guiot {\\it et. al.}\\cite{West2001,Guiot2003}. The results suggest that the universal similar...

  12. Macroscopic characterization of cell electroporation in biological tissue based on electrical measurements

    Science.gov (United States)

    Cima, Lionel F.; Mir, Lluis M.

    2004-11-01

    A method is described to experimentally determine the temporal evolution of state variables involved in the electroporation of biological tissue, i.e., the transmembrane voltage and the macroscopic current flowing in the electropores. Indeed, the electrical parameters of the extracellular, intracellular, and unaltered membrane contributions as well as the electropores electrical characteristics can be deduced from the measurement of the tissue bioimpedance and from the variations of both the macroscopic voltage applied to the tissue and the delivered current.

  13. Review to better understand the macroscopic subtypes and histogenesis of intrahepatic cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Yuichi; Sanada; Yujo; Kawashita; Satomi; Okada; Takashi; Azuma; Shigetoshi; Matsuo

    2014-01-01

    Intrahepatic cholangiocarcinoma is macroscopically classified into three subtypes, mass-forming-type, periductal infiltrating-type, and intraductal growth-type. Each subtype should be preoperatively differentiated to perform the valid surgical resection. Recent researches have revealed the clinical, radiologic, pathobiological characteristics of each subtype. We reviewed recently published studies covering various aspects of intrahepatic cholangiocarcinoma(ICC), focusing especially on the macroscopic subtypes and stem cell features to better understand the pathophysiology of ICC and to establish the valid therapeutic strategy.

  14. Critical Current in YBCO Coated Conductors in the Presence of a Macroscopic Defect (POSTPRINT)

    Science.gov (United States)

    2010-03-01

    AFRL-RZ-WP-TP-2010-2084 CRITICAL CURRENT IN YBCO COATED CONDUCTORS IN THE PRESENCE OF A MACROSCOPIC DEFECT (POSTPRINT) Milan Polak and...CRITICAL CURRENT IN YBCO COATED CONDUCTORS IN THE PRESENCE OF A MACROSCOPIC DEFECT (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c...display, or disclose the work. 14. ABSTRACT We have studied the effects of localized defects in the YBCO coated conductors on the critical current. The

  15. Emergence of Macroscopic Transport Barriers from Staircase Structures

    Science.gov (United States)

    Ashourvan, Arash; Diamond, Patrick H.

    2016-10-01

    A theory is presented for the formation and evolution of coupled density staircases (SC) and zonal shear profiles in a simple model of drift-wave turbulence. Density, vorticity and fluctuation potential enstrophy are the fields evolved for this system. Formation of SC structures is due to inhomogeneous mixing of generalized potential vorticity (PV), resulting in the sharpening of density and vorticity gradients in some regions and weakening them in others. The positive feedback which drives SC formation is implemented via a Rhines scale dependent mixing length. When PV gradients steepen, the density SC structure develops into a lattice of mesoscale `jumps', and `steps', which are respectively, regions of local gradient steepening and flattening. The jumps merge and migrate in radius, leading to the development of macroscale profile structures from mesoscale elements. Furthermore, depending on the sources and boundary conditions, either a region of enhanced confinement, or a region with strong turbulence can form at the edge. We present extensive studies of bifurcation physics of the global state, including results on the flux-gradient landscapes. This model is the first to demonstrate how mesoscale condensation of SCs leads to global states of enhanced confinement. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, under Award Numbers DE-FG02-04ER54738 and DE-SC0008378.

  16. Neutron irradiation and high temperature effects on amorphous Fe-based nano-coatings on steel - A macroscopic assessment

    Science.gov (United States)

    Simos, N.; Zhong, Z.; Dooryhee, E.; Ghose, S.; Gill, S.; Camino, F.; Şavklıyıldız, İ.; Akdoğan, E. K.

    2017-06-01

    The study revealed that loss of ductility in an amorphous Fe-alloy coating on a steel substrate composite structure was essentially prevented from occurring, following radiation with modest neutron doses of ∼2 × 1018 n/cm2. At the higher neutron dose of ∼2 × 1019, macroscopic stress-strain analysis showed that the amorphous Fe-alloy nanostructured coating, while still amorphous, experienced radiation-induced embrittlement, no longer offering protection against ductility loss in the coating-substrate composite structure. Neutron irradiation in a corrosive environment revealed exemplary oxidation/corrosion resistance of the amorphous Fe-alloy coating, which is attributed to the formation of the Fe2B phase in the coating. To establish the impact of elevated temperatures on the amorphous-to-crystalline transition in the amorphous Fe-alloy, electron microscopy was carried out which confirmed the radiation-induced suppression of crystallization in the amorphous Fe-alloy nanostructured coating.

  17. Ear Tumors

    Science.gov (United States)

    ... Japanese Espaniol Find information on medical topics, symptoms, drugs, procedures, news and more, written in everyday language. * This is ... the Ears, Nose, and Throat Additional Content Medical News Ear Tumors ... NOTE: This is the Consumer Version. DOCTORS: Click ...

  18. Pituitary tumor

    Science.gov (United States)

    ... enough of its hormones. This condition is called hypopituitarism . The causes of pituitary tumors are unknown. Some ... Cyst Endocrine glands Gigantism Growth hormone test Hyperthyroidism Hypopituitarism Multiple endocrine neoplasia (MEN) I Prolactin blood test ...

  19. Wilms' Tumor

    Science.gov (United States)

    ... team and have training in child development, recreation, psychology or social work. If your child must remain ... conditions/wilms-tumor/basics/definition/CON-20043492 . Mayo Clinic Footer Legal Conditions and Terms Any use of ...

  20. Tumor Grade

    Science.gov (United States)

    ... Other Funding Find NCI funding for small business innovation, technology transfer, and contracts Training Cancer Training at ... much of the tumor tissue has normal breast (milk) duct structures Nuclear grade : an evaluation of the ...

  1. Pituitary Tumors

    Science.gov (United States)

    ... impairment, and behavioral changes. Tumors can also either produce excessive amounts of hormone or limit how much hormone is produced. The hormones most commonly affected include: growth hormone (regulates body height and structure), prolactin (controls ...

  2. Tumor response to ionizing radiation and combined 2-deoxy-D-glucose application in EATC tumor bearing mice: monitoring of tumor size and microscopic observations

    Energy Technology Data Exchange (ETDEWEB)

    Latz, D. (Dept. of Radiotherapy, Heidelberg Univ. (Germany)); Thonke, A. (Inst. of Biophysics, Frankfurt Univ. (Germany)); Jueling-Pohlit, L. (Inst. of Biophysics, Frankfurt Univ. (Germany)); Pohlit, W. (Inst. of Biophysics, Frankfurt Univ. (Germany))

    1993-07-01

    The present study deals with the changes induced by two fractionation schedules (5x9 Gy and 10x4.5 Gy; 30 MeV-electrons) of ionizing radiations and 2-Deoxy-D-Glucose (2-DG) application on EATC tumor bearing swiss albino mice. The monitoring of tumor response was carried out by means of calliper measurement on the macroscopic level and by histopathological examination of tumor preparations stained with hematoxiline and eosine on the microscopic level. The tumor material was assessed at suitable intervals after treatment by killing the animals. The tumor response was analysed in the histological preparations and the thickness of the tumor band was determined quantitatively by an ocularmicrometric technique. Tumor damage was most extensive in the combined treated animals (5x9 Gy + 2-DG). Only in this group local tumor control was achievable. The histological analysis of tumor preparations revealed additional data about treatment-induced changes in the tumor compared to the measurement of the tumor volume with mechanical callipers. We also found that the treatment outcome could be predicted from the histopathological analysis. It is concluded that studies involving histopathological examinations may give some insight into the way cancer is controlled by radiotherapy and may be of value in prognosis and selection of treatment in patients. (orig.)

  3. Circulating Fibronectin Controls Tumor Growth

    Directory of Open Access Journals (Sweden)

    Anja von Au

    2013-08-01

    Full Text Available Fibronectin is ubiquitously expressed in the extracellular matrix, and experimental evidence has shown that it modulates blood vessel formation. The relative contribution of local and circulating fibronectin to blood vessel formation in vivo remains unknown despite evidence for unexpected roles of circulating fibronectin in various diseases. Using transgenic mouse models, we established that circulating fibronectin facilitates the growth of bone metastases by enhancing blood vessel formation and maturation. This effect is more relevant than that of fibronectin produced by endothelial cells and pericytes, which only exert a small additive effect on vessel maturation. Circulating fibronectin enhances its local production in tumors through a positive feedback loop and increases the amount of vascular endothelial growth factor (VEGF retained in the matrix. Both fibronectin and VEGF then cooperate to stimulate blood vessel formation. Fibronectin content in the tumor correlates with the number of blood vessels and tumor growth in the mouse models. Consistent with these results, examination of three separate arrays from patients with breast and prostate cancers revealed that a high staining intensity for fibronectin in tumors is associated with increased mortality. These results establish that circulating fibronectin modulates blood vessel formation and tumor growth by modifying the amount of and the response to VEGF. Furthermore, determination of the fibronectin content can serve as a prognostic biomarker for breast and prostate cancers and possibly other cancers.

  4. Ependymal tumors.

    Science.gov (United States)

    Moynihan, Timothy J

    2003-12-01

    Ependymal tumors are rare malignancies that arise from the cells that line the ventricles and central canal of the spinal cord. Although they are more common in children, adults may also be effected by ependymal tumors. Prognosis is dependent on tumor location, histology, especially for myxopapillary tumors that tend to occur in the lumbar spine, extent of surgical resection, and stage of disease. Standard therapy consists of complete resection when feasible. The exact role of adjuvant radiotherapy in patients with radiographically confirmed complete resection is poorly defined. Patients with known residual disease may benefit from local radiation therapy, but the extent of radiation field and total dose are controversial. Even in patients treated with involved field radiotherapy, most relapses occur within the original tumor bed, thus local control remains the biggest obstacle to effective therapy. Chemotherapy has little impact against this tumor and has no role in the adjuvant setting, outside of a well designed clinical trial, with the possible exception of children younger than 5 years in an effort to delay radiation. A minority of patients may respond to one of several chemotherapy regimens at the time of recurrence, but the impact of this therapy is limited. Newer treatment strategies are needed.

  5. Macroscopic Dust in Protoplanetary Disks - From Growth to Destruction

    CERN Document Server

    Deckers, Johannes

    2014-01-01

    The collision dynamics of dusty bodies are crucial for planetesimal formation. Especially decimeter agglomerates are important in the different formation models. Therefore, in continuation of our experiments on mutual decimeter collisions, we investigate collisions of centimeter onto decimeter dust agglomerates in a small drop tower under vacuum conditions (p<5*10^{-1} mbar) at a mean collision velocity of 6.68 +- 0.67m/s. We use quartz dust with irregularly shaped micrometer grains. Centimeter projectiles with different diameters, masses and heights are used, their typical volume filling factor is Phi_{p,m}=0.466+-0.02. The decimeter agglomerates have a mass of about 1.5kg, a diameter and height of 12cm and a mean filling factor of Phi_{t,m}=0.44+-0.004. At lower collision energies only the projectile gets destroyed and mass is transferred to the target. The accretion efficiency decreases with increasing obliquity and increasing difference in filling factor, if the projectile is more compact than the targ...

  6. Tackling the vascular heterogeneity issue in tumors : identification of novel targets for tumor therapy

    NARCIS (Netherlands)

    Roodink, I.

    2009-01-01

    This thesis focuses on the identification of novel vascular targeting agents directed against tumor endothelium and the expression patterns of their targets in (clinical) tumor samples. Tumors obtain their blood supply by the formation of new vessels and/or by the incorporation, and possibly

  7. Tackling the vascular heterogeneity issue in tumors : identification of novel targets for tumor therapy

    NARCIS (Netherlands)

    Roodink, I.

    2009-01-01

    This thesis focuses on the identification of novel vascular targeting agents directed against tumor endothelium and the expression patterns of their targets in (clinical) tumor samples. Tumors obtain their blood supply by the formation of new vessels and/or by the incorporation, and possibly subsequ

  8. Tumor Types: Understanding Brain Tumors

    Science.gov (United States)

    ... Classification of Tumors of the Central Nervous System Purchase WHO Blue Book NBTS Official Statement Questions and ... Privacy Copyright Site Search Search term Submit Submit Facebook Twitter YouTube Flickr

  9. Malignant tumors in an ancient Egyptian population.

    Science.gov (United States)

    Zink, A; Rohrbach, H; Szeimies, U; Hagedorn, H G; Haas, C J; Weyss, C; Bachmeier, B; Nerlich, A G

    1999-01-01

    Since it is still an open debate whether malignant tumors are mainly influenced by environmental factors, the frequency of such malignant tumors in historic populations with different living conditions is of particular interest. In the present study, we investigated the occurrence of malignant tumors affecting bone tissue in a population of mumrnies and skeletons, which had been excavated from the large necropolis of Thebes-West, Upper Egypt. Our study material comprised a series of at least 415 individuals (thereof 325 adults) dating from approx. 1500-500 B.C. All individuals had been mummified, but were severely damaged and partially broken by grave robbers, so that often only parts of the mummies/skeletons were available for investigation. The available specimens were subjected to careful macroscopic examination, while isolated findings were radiologically analyzed. Using this approach, we identified at least 4 cases showing malignant tumors affecting the skeleton. In two cases, multiple mixed osteolytic-osteoblastic lesions suggested multiple metastases from carcinomas. Two further individuals presented with multiple osteolyses (vertebra, pelvis, skull) most suggestive of multiple myeloma. The observation of at least 4 cases of malignant tumors with osseous manifestation in a series of 325 adult individuals provides clear evidence that malignant tumors were not a rare event in the ancient Egyptian study population, particularly when the limitations of a study of tumors manifested only in osseous remnants are taken into consideration. A calculation of the age- and sex-adjusted tumor frequency in our material in comparison with a recent model for such a material by Waldron (1996) indicates that the rate of malignant tumors with bone affection in our series is higher than in an English population from 1901-1905, although lower than in a comparable present day population. This clearly indicates that important factors affecting malignant tumors were effective even

  10. Polyelectrolyte surfactant aggregates and their deposition on macroscopic surfaces

    CERN Document Server

    Voisin, D

    2002-01-01

    Oppositely charged surfactant and polyelectrolyte are present in hair shampoos and conditioners, together with particles (e.g. anti-dandruff agents for scalp) and droplets (e.g. silicone oil for the hair). These are normally formulated at high surfactant concentrations, beyond the flocculation region for the polyelectrolyte concentration used. However, on dilution with water, during application, flocs are formed which carry the particles and droplets to the scalp and hair. The addition of an anionic surfactant to an aqueous solution of cationic polyelectrolyte, at a given concentration, can lead to the formation of polyelectrolyte-surfactant 'particles', in which the surfactant 'binds' to the polyelectrolyte. This occurs from the critical association concentration (CAC), up to the surfactant concentration corresponding to maximum binding. Within this range of surfactant concentrations, the surfactant bound to the polyelectrolyte is thought to associate to form what might be termed 'internal micelles'. Each po...

  11. Tough and Thermosensitive Poly(N-isopropylacrylamide)/Graphene Oxide Hydrogels with Macroscopically Oriented Liquid Crystalline Structures.

    Science.gov (United States)

    Zhu, Zhongcheng; Li, Yang; Xu, Hui; Peng, Xin; Chen, Ya-Nan; Shang, Cong; Zhang, Qin; Liu, Jiaqi; Wang, Huiliang

    2016-06-22

    Bulk graphene oxide (GO) nanocomposite materials with macroscopically oriented GO liquid crystalline (LC) structures exhibit interesting anisotropic properties, but their facile preparations remain challenging. This work reports for the first time the facile preparation of poly(N-isopropylacrylamide) (PNIPAM)/GO nanocomposite hydrogels with macroscopically oriented LC structures with the assistance of a flow field induced by vacuum degassing and the in situ polymerization accelerated by GO. The hydrogel prepared with a GO concentration of 5.0 mg mL(-1) exhibits macroscopically aligned LC structures, which endow the gels with anisotropic optical, mechanical properties, and dimensional changes during the phase transition. The hydrogels show dramatically enhanced tensile mechanical properties and phase transition rates. The oriented LC structures are not damaged during the phase transition of the PNIPAM/GO hydrogels, and hence their LC behavior undergoes reversible change. Moreover, highly oriented LC structures can also be formed when the gels are elongated, even for the gels which do not have macroscopically oriented LC structures. Very impressively, the oriented LC structures in the hydrogels can be permanently maintained by drying the gel samples elongated to and then kept at a constant tensile strain. The thermosensitive nature of PNIPAM and the angle-dependent nature of the macroscopically aligned GO LC structures allow the practical applications of the PNIPAM/GO hydrogels as optical switches, soft sensors, and actuators and so on.

  12. Crack Coalescence in Molded Gypsum and Carrara Marble: Part 1. Macroscopic Observations and Interpretation

    Science.gov (United States)

    Wong, L. N. Y.; Einstein, H. H.

    2009-06-01

    Cracking and coalescence behavior has been studied experimentally with prismatic laboratory-molded gypsum and Carrara marble specimens containing two parallel pre-existing open flaws. This was done at both the macroscopic and the microscopic scales, and the results are presented in two separate papers. This paper (the first of two) summarizes the macroscopic experimental results and investigates the influence of the different flaw geometries and material, on the cracking processes. In the companion paper (also in this issue), most of the macroscopic deformation and cracking processes shown in this present paper will be related to the underlying microscopic changes. In the present study, a high speed video system was used, which allowed us to precisely observe the cracking mechanisms. Nine crack coalescence categories with different crack types and trajectories were identified. The flaw inclination angle ( β), the ligament length ( L), that is, intact rock length between the flaws, and the bridging angle ( α), that is, the inclination of a line linking up the inner flaw tips, between two flaws, had different effects on the coalescence patterns. One of the pronounced differences observed between marble and gypsum during the compression loading test was the development of macroscopic white patches prior to the initiation of macroscopic cracks in marble, but not in gypsum. Comparing the cracking and coalescence behaviors in the two tested materials, tensile cracking generally occurred more often in marble than in gypsum for the same flaw pair geometries.

  13. Thermal Equilibrium of a Macroscopic Quantum System in a Pure State

    Science.gov (United States)

    Goldstein, Sheldon; Huse, David A.; Lebowitz, Joel L.; Tumulka, Roderich

    2015-09-01

    We consider the notion of thermal equilibrium for an individual closed macroscopic quantum system in a pure state, i.e., described by a wave function. The macroscopic properties in thermal equilibrium of such a system, determined by its wave function, must be the same as those obtained from thermodynamics, e.g., spatial uniformity of temperature and chemical potential. When this is true we say that the system is in macroscopic thermal equilibrium (MATE). Such a system may, however, not be in microscopic thermal equilibrium (MITE). The latter requires that the reduced density matrices of small subsystems be close to those obtained from the microcanonical, equivalently the canonical, ensemble for the whole system. The distinction between MITE and MATE is particularly relevant for systems with many-body localization for which the energy eigenfuctions fail to be in MITE while necessarily most of them, but not all, are in MATE. We note, however, that for generic macroscopic systems, including those with MBL, most wave functions in an energy shell are in both MATE and MITE. For a classical macroscopic system, MATE holds for most phase points on the energy surface, but MITE fails to hold for any phase point.

  14. Testicular tumors

    Directory of Open Access Journals (Sweden)

    Giovanni Rosti

    2011-12-01

    Full Text Available Germ cell tumors of the testes represent a unique paradigm of diseases which can be cured even in extremely advanced phase. Unfortunately, this makes them unique among adult solid tumors. Seminoma and non seminoma are relatively rare with approximatively 25,000 patients in Europe per year, but numbers are increasing world wide. Different strategies are needed depending on stage and prognostic scores. Seminoma is extremely sensitive to radiation therapy and chemotherapy, while all germ cell tumors show a very good response to chemotherapy. Clinical stage I seminoma is currently treated with radiation, single course carboplatin or surveillance policy. Clinical stage I non seminoma can also be approached with different strategies such as retroperitoneal lymph node dissection, observation or one-two courses of standard chemotherapy. Stage II seminoma may be treated with either radiation or chemotherapy, while for all advanced stages chemotherapy is mandatory. Since the mid-eighties PEB (Cisplatin, Etoposide and Bleomycin is the regimen of choice and no other schedule has proved superior in terms of efficacy. Surgery on the residual disease is crucial to the whole strategy and should be performed or attempted in all cases. Consequently, the correct treatment strategy for these tumors does not depend only on the ability of a single physician, but on a skilled team specialized in this particular tumor. Second line therapies (VeIP, PEI, TIP can cure 25%–40% of patients, but improved strategies for resistant tumors are desperately needed. High-dose chemotherapy has shown very good results in some studies while being less impressive in others. In any case, it should remain an option for relapsing patients and could be used in some cases of upfront chemotherapy in patients with slow marker decline, but this should only be considered in referring centers.

  15. Tumor thrombus

    DEFF Research Database (Denmark)

    Ravina, Mudalsha; Hess, Søren; Chauhan, Mahesh Singh

    2014-01-01

    PURPOSE: Thrombosis in cancer may manifest itself as venous thromboembolic disease or tumor thrombosis (TT). We present our experience with incidentally detected TT on FDG PET/CT in 21 oncologic patients. PATIENTS AND METHODS: We retrospectively reviewed all FDG PET/CT examinations during a 5-year......), but most other major branches of the venous vasculature was represented, and some patients had thrombi in several vessels. FDG uptake was linear in 7 patients, linear with a dilated vessel in 6 patients, and focal in 7 patients. The mean SUVmax of the primary tumors was 10.3 (range, 2.6-31.2; median, 6...

  16. Multiparametric classification links tumor microenvironments with tumor cell phenotype.

    Directory of Open Access Journals (Sweden)

    Bojana Gligorijevic

    2014-11-01

    Full Text Available While it has been established that a number of microenvironment components can affect the likelihood of metastasis, the link between microenvironment and tumor cell phenotypes is poorly understood. Here we have examined microenvironment control over two different tumor cell motility phenotypes required for metastasis. By high-resolution multiphoton microscopy of mammary carcinoma in mice, we detected two phenotypes of motile tumor cells, different in locomotion speed. Only slower tumor cells exhibited protrusions with molecular, morphological, and functional characteristics associated with invadopodia. Each region in the primary tumor exhibited either fast- or slow-locomotion. To understand how the tumor microenvironment controls invadopodium formation and tumor cell locomotion, we systematically analyzed components of the microenvironment previously associated with cell invasion and migration. No single microenvironmental property was able to predict the locations of tumor cell phenotypes in the tumor if used in isolation or combined linearly. To solve this, we utilized the support vector machine (SVM algorithm to classify phenotypes in a nonlinear fashion. This approach identified conditions that promoted either motility phenotype. We then demonstrated that varying one of the conditions may change tumor cell behavior only in a context-dependent manner. In addition, to establish the link between phenotypes and cell fates, we photoconverted and monitored the fate of tumor cells in different microenvironments, finding that only tumor cells in the invadopodium-rich microenvironments degraded extracellular matrix (ECM and disseminated. The number of invadopodia positively correlated with degradation, while the inhibiting metalloproteases eliminated degradation and lung metastasis, consistent with a direct link among invadopodia, ECM degradation, and metastasis. We have detected and characterized two phenotypes of motile tumor cells in vivo, which

  17. Macroscopic Properties of Hollow Cone Spray Using an Outwardly Opening Piezoelectric Injector in GCI Engine

    KAUST Repository

    Cheng, Penghui

    2016-07-01

    Fuel mixture formation and spray characteristics are crucial for the advancement of Gasoline Compression Ignition (GCI) engine. For investigations of spray characteristics, a high-pressure high-temperature spray chamber with constant volume has been designed, tested and commissioned at CCRC, KAUST. Back light illumination technique has been applied to investigate the macroscopic spray properties of an outwardly opening piezoelec- tric injector. Three parameters including injection pressure, ambient pressure, and ambient temperature have been involved. A total of 18 combinations of experimental conditions were tested under non-reactive conditions. Through qualitative analysis of spray morphology under different operating conditions, an apparent distinction of spray morphology has been noticed. Spray morphology and propagation have shown strong dependencies on ambient pressure and ambient tempera- ture while injection pressure has a negligible effect on spray shape. Increasingly compact and bushier spray patterns were observed in the cases of high ambient pressure due to in- creasing aerodynamic drag force on spray boundary. It should also be noted that ambient temperature plays a fairly important role in fuel evaporation rate. At 200 °C, oscillating and considerably short spray shape was produced. Also, circumferential ring-like vortices and distinctive string-like structures have been identified for the fuel spray exiting this hollow cone injector. It has been observed that high ambient pressure conditions (Pamb = 4 bar and 10.5 bar) are favorable to the vortices generation, which has also been reported in previous literature. The quantitative description of macroscopic spray properties reveals that ambient pres- sure and ambient temperature are found to be the most influential parameters on liquid penetration length. The rise of ambient pressure results in considerably shorter liquid pen- etration length. Ambient temperature also appears to be a very effective

  18. Elastic rods with incompatible strain: Macroscopic versus microscopic buckling

    Science.gov (United States)

    Lestringant, Claire; Audoly, Basile

    2017-06-01

    We consider the buckling of a long prismatic elastic solid under the combined effect of a pre-stress that is inhomogeneous in the cross-section, and of a prescribed displacement of its endpoints. A linear bifurcation analysis is carried out using different structural models (namely a double beam, a rectangular thin plate, and a hyper-elastic prismatic solid in 3-d): it yields the buckling mode and the wavenumber qc that are first encountered when the end-to-end displacement is progressively decreased with fixed pre-stress. For all three structural models, we find a transition from a long-wavelength (qc = 0) to a short-wavelength first buckling mode (qc ≠ 0) when the inhomogeneous pre-stress is increased past a critical value. A method for calculating the critical inhomogeneous pre-stress is proposed based on a small-wavenumber expansion of the buckling mode. Overall, our findings explain the formation of multiple perversions in elastomer strips, as well as the large variations in the number of perversions as a function of pre-stress and cross-sectional geometry, as reported by Liu et al. (2014).

  19. Superior sulcus tumors (Pancoast tumors).

    Science.gov (United States)

    Marulli, Giuseppe; Battistella, Lucia; Mammana, Marco; Calabrese, Francesca; Rea, Federico

    2016-06-01

    Superior Sulcus Tumors, frequently termed as Pancoast tumors, are a wide range of tumors invading the apical chest wall. Due to its localization in the apex of the lung, with the potential invasion of the lower part of the brachial plexus, first ribs, vertebrae, subclavian vessels or stellate ganglion, the superior sulcus tumors cause characteristic symptoms, like arm or shoulder pain or Horner's syndrome. The management of superior sulcus tumors has dramatically evolved over the past 50 years. Originally deemed universally fatal, in 1956, Shaw and Paulson introduced a new treatment paradigm with combined radiotherapy and surgery ensuring 5-year survival of approximately 30%. During the 1990s, following the need to improve systemic as well as local control, a trimodality approach including induction concurrent chemoradiotherapy followed by surgical resection was introduced, reaching 5-year survival rates up to 44% and becoming the standard of care. Many efforts have been persecuted, also, to obtain higher complete resection rates using appropriate surgical approaches and involving multidisciplinary team including spine surgeon or vascular surgeon. Other potential treatment options are under consideration like prophylactic cranial irradiation or the addition of other chemotherapy agents or biologic agents to the trimodality approach.

  20. Regulation of invadopodia by the tumor microenvironment

    Science.gov (United States)

    Gould, Christine M; Courtneidge, Sara A

    2014-01-01

    The tumor microenvironment consists of stromal cells, extracellular matrix (ECM), and signaling molecules that communicate with cancer cells. As tumors grow and develop, the tumor microenvironment changes. In addition, the tumor microenvironment is not only influenced by signals from tumor cells, but also stromal components contribute to tumor progression and metastasis by affecting cancer cell function. One of the mechanisms that cancer cells use to invade and metastasize is mediated by actin-rich, proteolytic structures called invadopodia. Here, we discuss how signals from the tumor environment, including growth factors, hypoxia, pH, metabolism, and stromal cell interactions, affect the formation and function of invadopodia to regulate cancer cell invasion and metastasis. Understanding how the tumor microenvironment affects invadopodia biology could aid in the development of effective therapeutics to target cancer cell invasion and metastasis. PMID:24714597

  1. Effects of macroscopic bulk defects on the damping behaviors of materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A large number of macroscopic pores or graphite particulates wereintroduced into commercially pure Al and ZA27 alloy by infiltration proces s to comparatively study the influence of macroscopic defects on the damping beh aviors of the materials. The mean diameter of the bulk defects is (1.0±0.5) mm, and the volume fractions of pores and graphite particulates are in the range of 50%—75% and 19%—94%, separately. It is shown that addition of a number of por es or graphite particulates can significantly improve the damping of commerciall y pure Al, due to the comprehensive effects of the macroscopic and microscopic d efects. However, the pores have little effect on the damping capacity of high da mping ZA27 alloy, and graphite particulates make the high temperature internal f riction peak decrease. It is considered that graphite particulates may repress t he intrinsic damping mechanism of ZA27 alloy.

  2. Microscopic and macroscopic theories for the dynamics of polar liquid crystals.

    Science.gov (United States)

    Wittkowski, Raphael; Löwen, Hartmut; Brand, Helmut R

    2011-10-01

    We derive and analyze the dynamic equations for polar liquid crystals in two spatial dimensions in the framework of classical dynamical density functional theory (DDFT). Translational density variations, polarization, and quadrupolar order are used as order-parameter fields. The results are critically compared with those obtained using the macroscopic approach of time-dependent Ginzburg-Landau (GL) equations for the analogous order-parameter fields. We demonstrate that, for both the microscopic DDFT and the macroscopic GL approach, the resulting dissipative dynamics can be derived from a dissipation function. We obtain microscopic expressions for all diagonal contributions and for many of the cross-coupling terms emerging from a GL approach. Thus, we establish a bridge between molecular correlations and macroscopic modeling for the dissipative dynamics of polar liquid crystals.

  3. The effect of interlayer adhesion on the mechanical behaviors of macroscopic graphene oxide papers.

    Science.gov (United States)

    Gao, Yun; Liu, Lu-Qi; Zu, Sheng-Zhen; Peng, Ke; Zhou, Ding; Han, Bao-Hang; Zhang, Zhong

    2011-03-22

    High mechanical performances of macroscopic graphene oxide (GO) papers are attracting great interest owing to their merits of lightweight and multiple functionalities. However, the loading role of individual nanosheets and its effect on the mechanical properties of the macroscopic GO papers are not yet well understood. Herein, we effectively tailored the interlayer adhesions of the GO papers by introducing small molecules, that is, glutaraldehyde (GA) and water molecules, into the gallery regions. With the help of in situ Raman spectroscopy, we compared the varied load-reinforcing roles of nanosheets, and further predicted the Young's moduli of the GO papers. Systematic mechanical tests have proven that the enhancement of the tensile modulus and strength of the GA-treated GO paper arose from the improved load-bearing capability of the nanosheets. On the basis of Raman and macroscopic mechanical tests, the influences of interlayer adhesions on the fracture mechanisms of the strained GO papers were inferred.

  4. Mechanical Behaviour of Materials Volume 1 Micro- and Macroscopic Constitutive Behaviour

    CERN Document Server

    François, Dominique; Zaoui, André

    2012-01-01

    Advances in technology are demanding ever-increasing mastery over the materials being used: the challenge is to gain a better understanding of their behaviour, and more particularly of the relations between their microstructure and their macroscopic properties.   This work, of which this is the first volume, aims to provide the means by which this challenge may be met. Starting from the mechanics of deformation, it develops the laws governing macroscopic behaviour – expressed as the constitutive equations – always taking account of the physical phenomena which underlie rheological behaviour. The most recent developments are presented, in particular those concerning heterogeneous materials such as metallic alloys, polymers and composites. Each chapter is devoted to one of the major classes of material behaviour.   As the subtitles indicate, Volume 1 deals with micro- and macroscopic constitutive behaviour and Volume 2 with damage and fracture mechanics. A third volume will be devoted to exercises and the...

  5. On the macroscopic quantization in mesoscopic rings and single-electron devices

    Science.gov (United States)

    Semenov, Andrew G.

    2016-05-01

    In this letter we investigate the phenomenon of macroscopic quantization and consider particle on the ring interacting with the dissipative bath as an example. We demonstrate that even in presence of environment, there is macroscopically quantized observable which can take only integer values in the zero temperature limit. This fact follows from the total angular momentum conservation combined with momentum quantization for bare particle on the ring. The nontrivial thing is that the model under consideration, including the notion of quantized observable, can be mapped onto the Ambegaokar-Eckern-Schon model of the single-electron box (SEB). We evaluate SEB observable, originating after mapping, and reveal new physics, which follows from the macroscopic quantization phenomenon and the existence of additional conservation law. Some generalizations of the obtained results are also presented.

  6. Student views of macroscopic and microscopic energy in physics and biology

    Science.gov (United States)

    Dreyfus, Benjamin W.; Redish, Edward F.; Watkins, Jessica

    2012-02-01

    Energy concepts are fundamental across the sciences, yet these concepts can be fragmented along disciplinary boundaries, rather than integrated into a coherent whole. To teach physics effectively to biology students, we need to understand students' disciplinary perspectives. We present interview data from an undergraduate student who displays multiple stances towards the concept of energy. At times he views energy in macroscopic contexts as a separate entity from energy in microscopic (particularly biological) contexts, while at other times he uses macroscopic physics phenomena as productive analogies for understanding energy in the microscopic biological context, and he reasons about energy transformations between the microscopic and macroscopic scales. This case study displays preliminary evidence for the context dependence of students' ability to translate energy concepts across scientific disciplines. This points to challenges that must be taken into account in developing curricula for biology students that integrate physics and biology concepts.

  7. Students' Views of Macroscopic and Microscopic Energy in Physics and Biology

    CERN Document Server

    Dreyfus, Benjamin W; Watkins, Jessica

    2011-01-01

    Energy concepts are fundamental across the sciences, yet these concepts can be fragmented along disciplinary boundaries, rather than integrated into a coherent whole. To teach physics effectively to biology students, we need to understand students' disciplinary perspectives. We present interview data from an undergraduate student who displays multiple stances towards the concept of energy. At times he views energy in macroscopic contexts as a separate entity from energy in microscopic (particularly biological) contexts, while at other times he uses macroscopic physics phenomena as productive analogies for understanding energy in the microscopic biological context, and he reasons about energy transformations between the microscopic and macroscopic scales. This case study displays preliminary evidence for the context dependence of students' ability to translate energy concepts across scientific disciplines. This points to challenges that must be taken into account in developing curricula for biology students th...

  8. Macroscopic extent of gastric mucosal atrophy: increased risk factor for esophageal squamous cell carcinoma in Japan

    Directory of Open Access Journals (Sweden)

    Kobayashi Noritoshi

    2009-05-01

    Full Text Available Abstract Background We aimed to estimate whether the macroscopic extent of gastric mucosal atrophy is associated with a risk for esophageal squamous cell carcinoma using a case-control study in Japanese subjects, a population known to have a high prevalence of CagA-positive H. pylori infection. Methods Two hundred and fifty-three patients who were diagnosed as having esophageal squamous cell carcinoma, and 253 sex- and age-matched controls were enrolled in the present study. The macroscopic extent of gastric mucosal atrophy was evaluated based on the Kimura and Takemoto Classification. A conditional logistic regression model with adjustment for potential confounding factors was used to assess the associations. Results Body gastritis, defined endoscopically, was independently associated with an increased risk for esophageal squamous cell carcinoma. Conclusion Our findings suggest that macroscopic body gastritis may be a risk factor for esophageal squamous cell carcinoma in Japan. Further studies are needed to confirm these findings.

  9. A strict experimental test of macroscopic realism in a superconducting flux qubit.

    Science.gov (United States)

    Knee, George C; Kakuyanagi, Kosuke; Yeh, Mao-Chuang; Matsuzaki, Yuichiro; Toida, Hiraku; Yamaguchi, Hiroshi; Saito, Shiro; Leggett, Anthony J; Munro, William J

    2016-11-04

    Macroscopic realism is the name for a class of modifications to quantum theory that allow macroscopic objects to be described in a measurement-independent manner, while largely preserving a fully quantum mechanical description of the microscopic world. Objective collapse theories are examples which aim to solve the quantum measurement problem through modified dynamical laws. Whether such theories describe nature, however, is not known. Here we describe and implement an experimental protocol capable of constraining theories of this class, that is more noise tolerant and conceptually transparent than the original Leggett-Garg test. We implement the protocol in a superconducting flux qubit, and rule out (by ∼84 s.d.) those theories which would deny coherent superpositions of 170 nA currents over a ∼10 ns timescale. Further, we address the 'clumsiness loophole' by determining classical disturbance with control experiments. Our results constitute strong evidence for the superposition of states of nontrivial macroscopic distinctness.

  10. Transformation-optics macroscopic visible-light cloaking beyond two dimensions

    CERN Document Server

    Chu, Chia-Wei; Lee, Chih Jie; Duan, Yubo; Tsai, Din Ping; Zhang, Baile; Luo, Yuan

    2014-01-01

    Transformation optics, a recent geometrical design strategy of controlling light by combining Maxwell's principles of electromagnetism with Einstein's general relativity, promises without precedent an invisibility cloaking device that can render a macroscopic object invisible in three dimensions. However, most previous proof-of-concept transformation-optics cloaking devices focused predominantly on two dimensions, whereas detection of a macroscopic object along its third dimension was always unfailing. Here, we report the first experimental demonstration of transformation-optics macroscopic visible-light cloaking beyond two dimensions. This almost-three-dimensional cloak exhibits three-dimensional (3D) invisibility for illumination near its center (i.e. with a limited field of view), and its ideal wide-angle invisibility performance is preserved in multiple two-dimensional (2D) planes intersecting in the 3D space. Both light ray trajectories and optical path lengths have been verified experimentally at the ma...

  11. Bouncing droplets: a classroom experiment to visualize wave-particle duality on the macroscopic level

    Science.gov (United States)

    Sleutel, Pascal; Dietrich, Erik; Van der Veen, Jan T.; van Joolingen, Wouter R.

    2016-09-01

    This study brings a recently discovered macroscopic phenomenon with wave-particle characteristics into the classroom. The system consists of a liquid droplet levitating over a vertically shaken liquid pool. The droplets allow visualization of a wave-particle system in a directly observable way. We show how to interpret this macroscopic phenomenon and how to set up and carry out this experiment. A class of students performed single slit diffraction experiments with droplets. By scoring individual droplet trajectories students find a diffraction pattern. This pilot application in the classroom shows that students can study and discuss the wave-particle nature of the bouncing droplet experiment. The experiment therefore provides a useful opportunity to show wave-particle behavior on the macroscopic level.

  12. Correlations between Nanoindentation Hardness and Macroscopic Mechanical Properties in DP980 Steels

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Mark D.; Choi, Kyoo Sil; Sun, Xin; Matlock, David K.; Packard, Corrine; Xu, Le; Barlat, Frederic

    2014-03-01

    Multiphase advanced high strength steels (AHSS) are being increasingly used in the automotive industry due to their low cost, good availability and excellent combination of strength and ductility. There is a keen interest from the automotive and steel industry for more fundamental understandings on the key microstructure features influencing the macroscopic properties, i.e., tensile properties, hole-expansion ratio and localized formability of AHSS. In this study, the micro- and macro-level properties for eight commercial DP980 steels are first characterized and quantified with various experimental methods. Correlations between macroscopic-level properties and relationships between various micro- and macro- properties for these steels are then established based on the experimental measurements. It is found that, despite their differences in their chemistry, processing parameters and sheet thickness, the eight DP980 steels do have common microstructural level properties governing their specific macroscopic properties in terms of strength, elongation and hole expansion performance.

  13. Macroscopic quantum superposition of spin ensembles with ultra-long coherence times via superradiant masing

    CERN Document Server

    Jin, Liang; Wrachtrup, Jörg; Liu, Ren-Bao

    2014-01-01

    Macroscopic quantum phenomena such as lasers, Bose-Einstein condensates, superfluids, and superconductors are of great importance in foundations and applications of quantum mechanics. In particular, quantum superposition of a large number of spins in solids is highly desirable for both quantum information processing and ultrasensitive magnetometry. Spin ensembles in solids, however, have rather short collective coherence time (typically less than microseconds). Here we demonstrate that under realistic conditions it is possible to maintain macroscopic quantum superposition of a large spin ensemble (such as about ~10^{14} nitrogen-vacancy center electron spins in diamond) with an extremely long coherence time ~10^8 sec under readily accessible conditions. The scheme, following the mechanism of superradiant lasers, is based on superradiant masing due to coherent coupling between collective spin excitations (magnons) and microwave cavity photons. The coherence time of the macroscopic quantum superposition is the ...

  14. Macroscopic effect of plasmon-driven high-order-harmonic generation

    Science.gov (United States)

    Wang, Feng; Liu, Weiwei; He, Lixin; Li, Liang; Wang, Baoning; Zhu, Xiaosong; Lan, Pengfei; Lu, Peixiang

    2017-09-01

    We present a numerical method to calculate the macroscopic harmonic spectrum generated from the gas-exposed nanostructure. This method includes the propagation of plasmonic and harmonic fields in the macroscopic medium as well as the response of the single atom exposed to plasmonic field. Based on the simulation, we demonstrate that the macroscopic harmonic yields drop dramatically in the high-energy region. This result well interprets the disagreement in the cutoff between the single-atom prediction and the experimental detection. Moreover, we also show that the harmonic cutoff difference induced by a π shift in carrier-envelope phase (CEP) of laser pulses depends sensitively on the spatial position. However, when the collective effect of plasmon-driven high-order-harmonic generation is considered, this cutoff difference is eliminated.

  15. Graphene-based macroscopic assemblies and architectures: an emerging material system.

    Science.gov (United States)

    Cong, Huai-Ping; Chen, Jia-Fu; Yu, Shu-Hong

    2014-11-07

    Due to the outstanding physicochemical properties arising from its truly two-dimensional (2D) planar structure with a single-atom thickness, graphene exhibits great potential for use in sensors, catalysts, electrodes, and in biological applications, etc. With further developments in the theoretical understanding and assembly techniques, graphene should enable great changes both in scientific research and practical industrial applications. By the look of development, it is of fundamental and practical significance to translate the novel physical and chemical properties of individual graphene nanosheets into the macroscale by the assembly of graphene building blocks into macroscopic architectures with structural specialities and functional novelties. The combined features of a 2D planar structure and abundant functional groups of graphene oxide (GO) should provide great possibilities for the assembly of GO nanosheets into macroscopic architectures with different macroscaled shapes through various assembly techniques under different bonding interactions. Moreover, macroscopic graphene frameworks can be used as ideal scaffolds for the incorporation of functional materials to offset the shortage of pure graphene in the specific desired functionality. The advantages of light weight, supra-flexibility, large surface area, tough mechanical strength, and high electrical conductivity guarantee graphene-based architectures wide application fields. This critical review mainly addresses recent advances in the design and fabrication of graphene-based macroscopic assemblies and architectures and their potential applications. Herein, we first provide overviews of the functional macroscopic graphene materials from three aspects, i.e., 1D graphene fibers/ribbons, 2D graphene films/papers, 3D network-structured graphene monoliths, and their composite counterparts with either polymers or nano-objects. Then, we present the promising potential applications of graphene-based macroscopic

  16. Spontaneous Fission and alpha -Decay Half-Lives of Superheavy Nuclei in Different Macroscopic Energy Models

    CERN Document Server

    Lojewski, Z; Pomorski, K

    2003-01-01

    Spontaneous fission half-lives (T sub s sub f) of the heaviest nuclei are calculated in the macroscopic-microscopic approach based on the deformed Woods-Saxon potential. Four different models of the macroscopic energy are examined and their influence on the results is discussed. The calculations of (T sub s sub f) are performed within WKB approximation. Multi-dimensional dynamical-programming method (MDP) is applied to minimize the action integral in a 3-dimensional space of deformation parameters describing the nuclear shape (beta sub 2 ,beta sub 4 ,beta sub 6).

  17. Comparison between Cooling Rate Dependence of Macroscopic and Microscopic Quantities in Simulated Aluminium Glass

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-Song; ZHU Zhen-Gang

    2000-01-01

    Constant-pressure molecular dynamics simulations and an analysis of the local atomic structures have been performed to study the cooling rate dependence of some macroscopic and microscopic quantities in aluminium glass. Macroscopic quantities, enthalpy and density, see an observable but small dependence on the cooling rate. Icosahedral ordering units exhibit strong cooling rate dependence, which is responsible for the dependence of the enthalpy and the density on the cooling rate; while the almost independence of some microstructural units such as the 1541, 1431 and 1421 pairs of the cooling rate may lead to a small dependence of the enthalpy and the density on the cooling rate.

  18. The flow around a macroscopical body by a colloid solution and the drag crisis

    CERN Document Server

    Iordanski, S V

    2013-01-01

    The motion of colloids in the flow field of a viscous liquid is investigated. The small colloid size compare to the macroscopical scale of the flow allow to calculate their velocity relative to that of the liquid. If the inner colloid density is larger then the density of the liquid the flow field has the domains where the colloid velocity is close to the liquid velocity. But in the domains with a strong braking of the liquid velocity the colloids are accelerated relative to the liquid. This effect is used for the qualitative explanation of the drag reduction in the flow around macroscopical bodies and in the pipes.

  19. Correlation between macroscopic porosity location and liquid metal pressure in centrifugal casting technique.

    Science.gov (United States)

    Vaidyanathan, T K; Schulman, A; Nielsen, J P; Shalita, S

    1981-01-01

    Radiographic analysis of uniform cylindrical castings fabricated by the centrifugal casting technique has revealed that the macroscopic porosity is dependent on the location of the sprue attachment to the casting. This is attributed to the significant pressure gradient associated with the centrifugal casting technique. The pressure gradient results in different heat transfer rates at portions of the castings near and away from the free surface of the button. Consequently, the macroscopic porosity is invariably at portions of the casting close to the free surface of the button. In addition, some optimized sprue-reservoir combinations could be predicted and proved, based on this pressure gradient concept.

  20. Departure of microscopic friction from macroscopic drag in molecular fluid dynamics

    Science.gov (United States)

    Hanasaki, Itsuo; Fujiwara, Daiki; Kawano, Satoyuki

    2016-03-01

    Friction coefficient of the Langevin equation and drag of spherical macroscopic objects in steady flow at low Reynolds numbers are usually regarded as equivalent. We show that the microscopic friction can be different from the macroscopic drag when the mass is taken into account for particles with comparable scale to the surrounding fluid molecules. We illustrate it numerically by molecular dynamics simulation of chloride ion in water. Friction variation by the atomistic mass effect beyond the Langevin regime can be of use in the drag reduction technology as well as the electro or thermophoresis.

  1. α decay energies and half-lives from a macroscopic-microscopic model

    Institute of Scientific and Technical Information of China (English)

    PENG Jin-Song; LI Lu-Lu; ZHOU Shan-Gui; ZHAO En-Guang

    2008-01-01

    α decay energies of 323 heavy nuclei with Z≥82 are evaluated with a macroscopic-microscopic model.In this model,the macroscopic part is treated by the continuous medium model and the microscopic part consists of shell and pairing corrections based on the Nilsson potential.α decay half-lives are calculated by Viola-Seaborg formula.The results of α decay energies and half-lives are compared with experimental values and satisfactory agreement is found.The recoiling effect of the daughter nucleus on α decay half-life is also discussed.

  2. A novel macroscopic traffic model based on generalized optimal velocity model

    Institute of Scientific and Technical Information of China (English)

    Zhou Xuan-Hao; Lu Yong-Zai

    2011-01-01

    In this paper, we adopt the coarse graining method proposed by Lee H K et al. to develop a macroscopic model from the microscopic traffic model-GOVM. The proposed model inherits the pararneter p which considers the influence of next-neareet car introduced in the GOVM model. The simulation results show that the new model is strictly consistent with the former microscopic model. Using this macroscopic model, we can avoid considering the details of each traffic on the road, and build more complex models such as road network model easily in the future.

  3. Metastable states and macroscopic quantum tunneling in a cold atom josephson ring

    Energy Technology Data Exchange (ETDEWEB)

    Solenov, Dmitry [Los Alamos National Laboratory; Mozyrsky, Dmitry [Los Alamos National Laboratory

    2009-01-01

    We study macroscopic properties of a system of weakly interacting neutral bosons confined in a ring-shaped potential with a Josephson junction. We derive an effective low energy action for this system and evaluate its properties. In particular we find that the system possesses a set of metastable current-carrying states and evaluate the rates of transitions between these states due to macroscopic quantum tunneling. Finally we discuss signatures of different metastable states in the time-of-flight images and argue that the effect is observable within currently available experimental technique.

  4. Effect of N-cadherin knock-down on tumor formation of EC9706 cells in nude mice%RNAi沉默N-cadherin表达对EC9706细胞裸鼠移植瘤生长的影响

    Institute of Scientific and Technical Information of China (English)

    李克; 刘莺; 刘文静; 侯新芳; 何素英; 王居峰

    2011-01-01

    AIM: To explore the effect of N - cadherin knock - down on the biological behavior of EC9706 cells in vivo.METHODS: The control vector pEGFP - MSCVneo and recombinant retroviral vector pMSCVneo/N - cadherin plasmids were transfected into esophageal squamous cell carcinoma( ESCC ) cell line EC9706 according to the manufacturers instructions.Stable EC9706 cell clones were selected using selection medium containing G418.Untreated EC9706 cells, control vector - transfected EC9706 cells and N - cadherin RNAi - transfected EC9706 cells were inoculated subcutaneously into the right flank of BALB/c mice ( 5 for each group ), respectively.When tumors became palpable, the diameters of the tumors were measured with a caliper each week after subcutaneous implantation, and the volume ( mm3 ) and weight ( g ) of the tumors were also calculated.Immunohistochemistry and Western blotting were employed to examine the expression levels of E - cadherin, N - cadherin and MMP - 9 in the tumor tissues.The cell apoptosis was analyzed by TUNEL method.RESULTS: Compared with untreated group and control vector group, there was an obvious decrease in the volumes and weights of the tumors in N - cadherin RNAi group ( P < 0.05 ).No difference of E - cadherin expression in the 3 groups was observed.However, the expression of N - cadherin and MMP - 9 in N - cadherin RNAi group was apparently reduced, and the positive number of cell apoptosis was obviously increased in N - cadherin RNAi group ( 106.81 ± 6.47 ) as compared with that in untreated group ( 51.55 ±4.68 ) and control vector group ( 54.17 ± 5.26 ).CONCLUSION: N - cadherin knock - down inhibits the tumor formation of EC9706 cells in nude mice by decreasing MMP - 9 expression , resulting in less degradation of ECM and less aggression of the cancer cells.N - cadherin is an important factor in the progression and metastasis of ESCC,and may serve as a potential molecular target for biotherapy of ESCC.%目的:探讨RNAi沉默N-cadherin表

  5. Macroscopic Anomalies and Pathological Findings in and Around the Achilles Tendon: Observations From 1661 Operations During a 40-Year Period

    National Research Council Canada - National Science Library

    Johansson, Kristian; Lempainen, Lasse; Sarimo, Janne; Laitala-Leinonen, Tiina; Orava, Sakari

    2014-01-01

    ...; Level of evidence, 4. Methods: The main macroscopic pathologies of 1661 chronic Achilles tendon overuse injuries, which were diagnosed and surgically treated by a single surgeon, were reviewed...

  6. Uncommon liver tumors

    Science.gov (United States)

    Wu, Chia-Hung; Chiu, Nai-Chi; Yeh, Yi-Chen; Kuo, Yu; Yu, Sz-Shian; Weng, Ching-Yao; Liu, Chien-An; Chou, Yi-Hong; Chiou, Yi-You

    2016-01-01

    Abstract Background: Beside hepatocellular carcinoma, metastasis, and cholangiocarcinoma, the imaging findings of other relatively uncommon hepatic lesions are less discussed in the literature. Imaging diagnosis of these lesions is a daily challenge. In this article, we review the imaging characteristics of these neoplasms. Methods: From January 2003 to December 2014, 4746 patients underwent liver biopsy or hepatic surgical resection in our hospital. We reviewed the pathological database retrospectively. Imaging of these lesions was reviewed. Results: Imaging findings of uncommon hepatic lesions vary. We discuss the typical imaging characteristics with literature review. Clinical and pathological correlations are also described. Primary hepatic lymphoma consists only of 1% of the extranodal non-Hodgkin lymphoma, and is defined as the one involving only the liver and perihepatic lymph nodes within 6 months after diagnosis. Combined hepatocellular and cholangiocarcinoma (cHCC-CC) shares some overlapping imaging characteristics with both HCC and cholangiocarcinoma because of being an admixture of them. Angiosarcoma is the most common hepatic mesenchymal tumor and is hypervascular in nature. Inflammatory pseudotumor is often heterogeneous on ultrasonography and with enhanced septations and rims in the portovenous phase after contrast medium. Angiomyolipoma (AML) typically presents with macroscopic fat components with low signal on fat-saturated magnetic resonance imaging (MRI) and presence of drainage vessels. Intraductal papillary neoplasm of the bile duct (IPNB) is thought of as a counterpart to the pancreatic intraductal papillary mucinous neoplasm. Most of the IPNBs secrete mucin and cause disproportional dilatation of the bile ducts. Mucinous cystic neoplasm (MCN) contains proteinaceous and colloidal components without ductal communication and characterizes with hyperintensity on T1-weighted imaging. Other extremely rare lesions, including epithelioid

  7. Tumor bioengineering using a transglutaminase crosslinked hydrogel.

    Directory of Open Access Journals (Sweden)

    Josephine Y Fang

    Full Text Available Development of a physiologically relevant 3D model system for cancer research and drug development is a current challenge. We have adopted a 3D culture system based on a transglutaminase-crosslinked gelatin gel (Col-Tgel to mimic the tumor 3D microenvironment. The system has several unique advantages over other alternatives including presenting cell-matrix interaction sites from collagen-derived peptides, geometry-initiated multicellular tumor spheroids, and metabolic gradients in the tumor microenvironment. Also it provides a controllable wide spectrum of gel stiffness for mechanical signals, and technical compatibility with imaging based screening due to its transparent properties. In addition, the Col-Tgel provides a cure-in-situ delivery vehicle for tumor xenograft formation in animals enhancing tumor cell uptake rate. Overall, this distinctive 3D system could offer a platform to more accurately mimic in vivo situations to study tumor formation and progression both in vitro and in vivo.

  8. Proposed stratigraphic nomenclature and macroscopic identification of lithostratigraphic units of the Paintbrush Group exposed at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Buesch, D.C.; Spengler, R.W.; Moyer, T.C.; Geslin, J.K.

    1996-09-01

    This paper describes the formations of the Paintbrush Group exposed at Yucca Mountain, Nevada, presents a detailed stratigraphic nomenclature for the Tiva Canyon and Topopah spring Tuffs, and discusses the criteria that define lithostratigraphic units. The Tiva Canyon and Topopah Spring Tuffs are divided into zones, subzones, and intervals on the basis of macroscopic features observed in surface exposures and borehole samples. Primary divisions reflect depositional and compositional zoning that is expressed by variations in crystal content, phenocryst assemblage, pumice content and composition, and lithic content. Secondary divisions define welding and crystlalization zones, depositional features, or fracture characteristics. Both formations are divided into crystal-rich and crystal-poor members that have an identical sequency of zones, although subzone designations vary slightly between the two units. The identified lithostratigraphic divisions can be used to approximate thermal-mechanical and hydrogeologic boundaries in the field. Linking these three systems of nomenclature provides a framework within which to correlate these properties through regions of sparse data.

  9. Capture of circulating tumor cells using photoacoustic flowmetry and two phase flow

    OpenAIRE

    O’Brien, Christine M.; Rood, Kyle D; Bhattacharyya, Kiran; DeSouza, Thiago; Sengupta, Shramik; Gupta, Sagar K.; Mosley, Jeffrey D.; Goldschmidt, Benjamin S.; Sharma, Nikhilesh; Viator, John A.

    2012-01-01

    Melanoma is the deadliest form of skin cancer, yet current diagnostic methods are unable to detect early onset of metastatic disease. Patients must wait until macroscopic secondary tumors form before malignancy can be diagnosed and treatment prescribed. Detection of cells that have broken off the original tumor and travel through the blood or lymph system can provide data for diagnosing and monitoring metastatic disease. By irradiating enriched blood samples spiked with cultured melanoma cell...

  10. Synthesis and Characterization of Ordered Mesoporous Silica with Controlled Macroscopic Morphology for Membrane Applications

    Science.gov (United States)

    Stohlman, Olive R.

    2011-12-01

    Ordered mesoporous materials have tunable pore sizes between 2 and 50 nm and are characterized by ordered pore structures and high surface areas (~1000 m2/g). This makes them particularly favorable for a number of membrane applications such as protein separation, polymer extrusion, nanowire fabrication and membrane reactors. These membranes can be fabricated as top-layers on macroporous supports or as embedded membranes in a dense matrix. The first part of the work deals with the hydrothermal synthesis and water-vapor/oxygen separation properties of supported MCM-48 and a new Al-MCM-48 type membrane for potential use in air conditioning systems. Knudsen-type permeation is observed in these membranes. The combined effect of capillary condensation and the aluminosilicate matrix resulted in the highest separation factor (142) in Al-MCM-48 membranes, with a water vapor permeance of 6x10 -8mol/m2·Pa·s. The second part focuses on synthesis of embedded mesoporous silica membranes with helically ordered pores by a novel Counter Diffusion Self-Assembly (CDSA) method. This method is an extension of the interfacial synthesis method for fiber synthesis using tetrabutylorthosilicate (TBOS) and cetyltrimethylammonium bromide (CTAB) as the silica source and surfactant respectively. The initial part of this study determined the effect of TBOS height and humidity on fiber formation. From this study, the range of TBOS heights for best microscopic and macroscopic ordering were established. Next, the CDSA method was used to successfully synthesize membranes, which were characterized to have good support plugging and an ordered pore structure. Factors that influence membrane synthesis and plug microstructure were determined. SEM studies revealed the presence of gaps between the plugs and support pores, which occur due to shrinking of the plug on drying. Development of a novel liquid deposition method to seal these defects constituted the last part of this work. Post sealing, excess

  11. Macroscopic and microscopic spectral properties of brain networks during local and global synchronization

    NARCIS (Netherlands)

    Maksimenko, V.A.; Lüttjohann, A.; Makarov, V.V.; Goremyko, M.V.; Koronovskii, A.A.; Nedaivozov, V.; Runnova, A.E.; Luijtelaar, E.L.J.M. van; Hramov, A.E.; Boccaletti, S.

    2017-01-01

    We introduce a practical and computationally not demanding technique for inferring interactions at various microscopic levels between the units of a network from the measurements and the processing of macroscopic signals. Starting from a network model of Kuramoto phase oscillators which evolve

  12. Macroscopic to Microscopic Scales of Particulate Dosimetry: From Source to Fate in the Body

    Science.gov (United States)

    Additional perspective with regards to particle dosimetry is achieved by exploring dosimetry across a range of scales from macroscopic to microscopic in scope. Typically, one thinks of dosimetry as what happens when a particle is inhaled, where it is deposited, and how it is clea...

  13. Understanding of Macroscopic, Microscopic and Symbolic Representations among Form Four Students in Solving Stoichiometric Problems

    Science.gov (United States)

    Sujak, Kamariah Binti; Daniel, Esther Gnanamalar Sarojini

    2017-01-01

    The purpose of this article is to determine the levels of understanding for solving Stoichiometry problems from the aspect of macroscopic, microscopic and symbolic representations of high, average and low achieving students after infusion of metacognitive skills. Nine form four students aged sixteen years old from a secondary school in Kuala…

  14. Effect of the isovector coupling channel on the macroscopic part of the nuclear binding energy

    Indian Academy of Sciences (India)

    S Haddad

    2013-05-01

    The effect of isovector coupling channel on the macroscopic part of the nuclear binding energy is studied using the relativistic density-dependent Thomas–Fermi approach. The dependency of this effect on the number of neutrons and protons is also studied. The isovector coupling channel leads to increased nuclear binding energy, and this effect increases with the increasing neutron number in the nucleus.

  15. Macroscopic quantum tunneling in π Josephson junctions with insulating ferromagnets and its application to phase qubits

    NARCIS (Netherlands)

    Kawabata, Shiro; Golubov, Alexander A.

    2007-01-01

    We theoretically investigate macroscopic quantum tunneling (MQT) in a current-biased π junction with a superconductor (S) and an insulating ferromagnet (IF). By using the functional integral method and the instanton approximation, the influence of the quasiparticle dissipation on MQT is found to be

  16. Chaotic advection at the pore scale: Mechanisms, upscaling and implications for macroscopic transport

    Science.gov (United States)

    Lester, D. R.; Trefry, M. G.; Metcalfe, G.

    2016-11-01

    The macroscopic spreading and mixing of solute plumes in saturated porous media is ultimately controlled by processes operating at the pore scale. Whilst the conventional picture of pore-scale mechanical dispersion and molecular diffusion leading to persistent hydrodynamic dispersion is well accepted, this paradigm is inherently two-dimensional (2D) in nature and neglects important three-dimensional (3D) phenomena. We discuss how the kinematics of steady 3D flow at the pore scale generate chaotic advection-involving exponential stretching and folding of fluid elements-the mechanisms by which it arises and implications of microscopic chaos for macroscopic dispersion and mixing. Prohibited in steady 2D flow due to topological constraints, these phenomena are ubiquitous due to the topological complexity inherent to all 3D porous media. Consequently 3D porous media flows generate profoundly different fluid deformation and mixing processes to those of 2D flow. The interplay of chaotic advection and broad transit time distributions can be incorporated into a continuous-time random walk (CTRW) framework to predict macroscopic solute mixing and spreading. We show how these results may be generalised to real porous architectures via a CTRW model of fluid deformation, leading to stochastic models of macroscopic dispersion and mixing which both honour the pore-scale kinematics and are directly conditioned on the pore-scale architecture.

  17. Simulation of root water uptake. I. Non-uniform transient salinity using different macroscopic reduction functions

    NARCIS (Netherlands)

    Homaee, M.; Dirksen, C.; Feddes, R.A.

    2002-01-01

    A macroscopic root extraction model was used with four different reduction functions for salinity stress in the numerical simulation model HYSWASOR. Most of the parameter values originally proposed for these functions did not provide good agreement with the experimental data. Therefore, the paramete

  18. Macroscopic modeling for heat and water vapor transfer in dry snow by homogenization.

    Science.gov (United States)

    Calonne, Neige; Geindreau, Christian; Flin, Frédéric

    2014-11-26

    Dry snow metamorphism, involved in several topics related to cryospheric sciences, is mainly linked to heat and water vapor transfers through snow including sublimation and deposition at the ice-pore interface. In this paper, the macroscopic equivalent modeling of heat and water vapor transfers through a snow layer was derived from the physics at the pore scale using the homogenization of multiple scale expansions. The microscopic phenomena under consideration are heat conduction, vapor diffusion, sublimation, and deposition. The obtained macroscopic equivalent model is described by two coupled transient diffusion equations including a source term arising from phase change at the pore scale. By dimensional analysis, it was shown that the influence of such source terms on the overall transfers can generally not be neglected, except typically under small temperature gradients. The precision and the robustness of the proposed macroscopic modeling were illustrated through 2D numerical simulations. Finally, the effective vapor diffusion tensor arising in the macroscopic modeling was computed on 3D images of snow. The self-consistent formula offers a good estimate of the effective diffusion coefficient with respect to the snow density, within an average relative error of 10%. Our results confirm recent work that the effective vapor diffusion is not enhanced in snow.

  19. Reservoir engineering of a mechanical resonator: generating a macroscopic superposition state and monitoring its decoherence

    Science.gov (United States)

    Asjad, Muhammad; Vitali, David

    2014-02-01

    A deterministic scheme for generating a macroscopic superposition state of a nanomechanical resonator is proposed. The nonclassical state is generated through a suitably engineered dissipative dynamics exploiting the optomechanical quadratic interaction with a bichromatically driven optical cavity mode. The resulting driven dissipative dynamics can be employed for monitoring and testing the decoherence processes affecting the nanomechanical resonator under controlled conditions.

  20. Temperature dependent nonlinear Hall effect in macroscopic Si-MOS antidot array

    OpenAIRE

    Kuntsevich, A. Yu.; Shupltetsov, A. V.; Nunuparov, M. S.

    2015-01-01

    By measuring magnetoresistance and Hall effect in classically moderate perpendicular magnetic field in Si-MOSFET-type macroscopic antidot array we found a novel effect: nonlinear with field, temperature- and density-dependent Hall resistivity. We discuss qualitative explanation of the phenomenon and suggest that it might originate from strong temperature dependence of the resistivity and mobility in the shells of the antidots.