4,097 research outputs found
VOLUMEN 16, NĂMERO 30 (1983-1984)
PROYECTO GEOTĂRMICO CHILES - CERRO NEGRO. Lozano, E.; Cruz, L.ZONAS HIDROGEOLĂGICAS DE COLOMBIA. Lobo-Guerrero, A.ESTUDIO GEOQUĂMICO Y PETROGRĂFICO DE ROCAS SUBVOLCĂNICAS ENTRE LA QUEBRADA CHIRAPOTO Y EL RĂO ARQUĂA (DEPARTAMENTO DE ANTIOQUIA Y CALDAS). SĂĄnchez, L. H.; Parra, R. A.; OrtĂz, F.GEOLOGĂA Y EXPERIENCIAS CONSTRUCTIVAS EN EL TĂNEL TUNJITA. Tejada, S. E.CONTRIBUCIĂN AL CONOCIMIENTO DEL PALEOZOICO SUPERIOR EN LA SECCIĂN QUETAME - VILLAVICENCIO. CortĂŠs, R.; De La Espriella, R.TECTĂNICA GRAVITACIONAL EN LA CORDILLERA ORIENTAL AL ESTE DE LA FALLA DE BOYACĂ (DEPARTAMENTO DE BOYACĂ). Reyes, Ch. I.AMBIENTES GEOLĂGICOS URANĂFEROS EN COLOMBIA. Ortega Montero, C
VOLUMEN 16, NĂMERO 30 (1983-1984)
PROYECTO GEOTĂRMICO CHILES - CERRO NEGRO. Lozano, E.; Cruz, L.ZONAS HIDROGEOLĂGICAS DE COLOMBIA. Lobo-Guerrero, A.ESTUDIO GEOQUĂMICO Y PETROGRĂFICO DE ROCAS SUBVOLCĂNICAS ENTRE LA QUEBRADA CHIRAPOTO Y EL RĂO ARQUĂA (DEPARTAMENTO DE ANTIOQUIA Y CALDAS). SĂĄnchez, L. H.; Parra, R. A.; OrtĂz, F.GEOLOGĂA Y EXPERIENCIAS CONSTRUCTIVAS EN EL TĂNEL TUNJITA. Tejada, S. E.CONTRIBUCIĂN AL CONOCIMIENTO DEL PALEOZOICO SUPERIOR EN LA SECCIĂN QUETAME - VILLAVICENCIO. CortĂŠs, R.; De La Espriella, R.TECTĂNICA GRAVITACIONAL EN LA CORDILLERA ORIENTAL AL ESTE DE LA FALLA DE BOYACĂ (DEPARTAMENTO DE BOYACĂ). Reyes, Ch. I.AMBIENTES GEOLĂGICOS URANĂFEROS EN COLOMBIA. Ortega Montero, C
DNA Methylation-Independent Reversion of Gemcitabine Resistance by Hydralazine in Cervical Cancer Cells
BACKGROUND: Down regulation of genes coding for nucleoside transporters and drug metabolism responsible for uptake and metabolic activation of the nucleoside gemcitabine is related with acquired tumor resistance against this agent. Hydralazine has been shown to reverse doxorubicin resistance in a model of breast cancer. Here we wanted to investigate whether epigenetic mechanisms are responsible for acquiring resistance to gemcitabine and if hydralazine could restore gemcitabine sensitivity in cervical cancer cells. METHODOLOGY/PRINCIPAL FINDINGS: The cervical cancer cell line CaLo cell line was cultured in the presence of increasing concentrations of gemcitabine. Down-regulation of hENT1 & dCK genes was observed in the resistant cells (CaLoGR) which was not associated with promoter methylation. Treatment with hydralazine reversed gemcitabine resistance and led to hENT1 and dCK gene reactivation in a DNA promoter methylation-independent manner. No changes in HDAC total activity nor in H3 and H4 acetylation at these promoters were observed. ChIP analysis showed H3K9m2 at hENT1 and dCK gene promoters which correlated with hyper-expression of G9A histone methyltransferase at RNA and protein level in the resistant cells. Hydralazine inhibited G9A methyltransferase activity in vitro and depletion of the G9A gene by iRNA restored gemcitabine sensitivity. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that acquired gemcitabine resistance is associated with DNA promoter methylation-independent hENT1 and dCK gene down-regulation and hyper-expression of G9A methyltransferase. Hydralazine reverts gemcitabine resistance in cervical cancer cells via inhibition of G9A histone methyltransferase
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE
In this small note we are concerned with the solution of Forward-Backward
Stochastic Differential Equations (FBSDE) with drivers that grow quadratically
in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem
is a comparison result that allows comparing componentwise the signs of the
control processes of two different qgFBSDE. As a byproduct one obtains
conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
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