Search results for "MTO"
showing 10 items of 538 documents
Guanosine Protects Glial Cells Against 6-Hydroxydopamine Toxicity
2014
Increasing body of evidence indicates that neuron-neuroglia interaction may play a key role in determining the progression of neurodegenerative diseases including Parkinson’s disease (PD), a chronic pathological condition characterized by selective loss of dopaminergic (DA) neurons in the substantia nigra. We have previously reported that guanosine (GUO) antagonizes MPP+-induced cytotoxicity in neuroblastoma cells and exerts neuroprotective effects against 6-hydroxydopamine (6-OHDA) and beta-amyloid-induced apoptosis of SH-SY5Y cells. In the present study we demonstrate that GUO protected C6 glioma cells, taken as a model system for astrocytes, from 6-OHDA-induced neurotoxicity. We show tha…
Concentration measurements in molecular gas mixtures with a two-pump pulse femtosecond polarization spectroscopy technique
2001
0021-9606; Recently, we have demonstrated the ability of the Raman-induced polarization spectroscopy (RIPS) technique to accurately determine concentration or polarizability anisotropy ratio in low-pressure binary molecular mixtures [E. Hertz, B. Lavorel, O. Faucher, and R. Chaux, J. Chem. Phys. 113, 6629 (2000)]. It has been also pointed out that macroscopic interference, occurring when two revivals associated to different molecules time overlap, can be used to achieve measurements with picosecond time resolution. The applicability of the technique is intrinsically limited to a concentration range where the signals of both molecules are of the same magnitude. In this paper, a two-pump puls…
PD-1-induced T cell exhaustion is controlled by a Drp1-dependent mechanism
2020
AbstractPD-1 signalling downregulates the T cell response, promoting an exhausted state in tumor-infiltrating T cells, through mostly unveiled molecular mechanisms. Drp1-dependent mitochondrial fission plays a crucial role to sustain T cell motility, proliferation, survival and glycolytic engagement and, interestingly, such processes are exactly those inhibited by PD-1 in tumor-infiltrating T cells. Here we show that the signature of PD-1pos CD8+ T cells infiltrating MC38-derived murine tumor mass is having downregulated Drp1 activity and more fused mitochondria, compared to PD-1neg counterparts. Also, PD-1pos lymphocytic elements infiltrating human colon cancer rarely express active Drp1. …
XPO1 (Exportin-1) Is a Major Regulator of Human Erythroid Differentiation. Potential Clinical Applications to Decrease Ineffective Erythropoiesis of …
2015
Abstract Background We and others have shown that normal human erythroid cell maturation requires a transient activation of caspase-3 at late stages of maturation (Zermati et al, J Exp Med 2001). We further documented that, in human erythroblasts, the chaperone HSP70 is constitutively expressed and, at late stages of maturation, translocates into the nucleus and protects GATA-1, the master transcriptional factor critical for erythropoiesis, from caspase-3 cleavage (Ribeil et al, Nature 2007). During the maturation of human β-TM erythroblasts, HSP70 is sequestrated by excess of α-globin chains in the cytoplasm and as a consequence, GATA-1 is no longer protected from caspase-3 cleavage result…
Intraocular pressure measurements during flap preparation using 2 femtosecond lasers and 1 microkeratome in human donor eyes
2012
Purpose To evaluate and compare intraocular pressures (IOPs) during flap preparations performed using 2 femtosecond lasers and a mechanical microkeratome in human donor globes. Setting University Medical Center Mainz, Mainz, and Euroeyes Clinic Stuttgart, Stuttgart, Germany. Design Experimental study. Methods A cannula was inserted through the optic nerve in human globes. The IOP was obtained continuously during flap preparation using the 60 kHz Intralase femtosecond laser, the 200 kHz Visumax femtosecond laser, or the Amadeus II microkeratome. For each experiment, a normal lamellar flap preparation (regular procedure) and a worst-case procedure (femtosecond laser interface was pressed agai…
Comparison of Intraocular Pressure During Corneal Flap Preparation Between a Femtosecond Laser and a Mechanical Microkeratome in Porcine Eyes
2011
To compare the increase in intraocular pressure (IOP) during corneal flap preparation in porcine eyes when using a femtosecond laser or a mechanical microkeratome.The present study was conducted at a university hospital and a private clinic.The vitreous IOP was directly measured with a cannula through the optic nerve in 24 porcine globes (n = 12 for each device). In the first procedure (worst-case procedure), the eye interface was lowered against the globe until abortion of the docking maneuver when using the IntraLase femtosecond laser (Abbott Medical Optics, Santa Ana, CA) or the suction ring was pressed very firmly against the globe when using the Amadeus microkeratome (Ziemer Ophthalmic…
Measurement of high order Kerr refractive index of major air components
2009
International audience; We measure the instantaneous electronic nonlinear refractive index of N2 , O2 , and Ar at room temperature for a 90 fs and 800 nm laser pulse. Measurements are calibrated by post-pulse molecular alignment through a polarization technique. At low intensity, quadratic coefficients n2 are determined. At higher intensities, a strong negative contribution with a higher nonlinearity appears, which leads to an overall negative nonlinear Kerr refractive index in air above 26 TW/cm2 .
Measurement of laser-induced alignment of molecules by cross defocusing
2005
0146-9592; The field-free alignment of CO2 produced in response to the excitation of a molecule by a high-intensity femtosecond pump pulse is measured with a simple coronography-like technique. The technique is based on the defocusing of a time-delayed probe pulse produced by the spatial distribution of aligned molecules. In the intensity regime explored here, the technique is shown to give valuable information about dynamic alignment. With the help of simulations, the degree of alignment is extracted from the data. (C) 2005 Optical Society of America.
Measurement of high order Kerr refractive index of major air components: erratum
2010
A clarification is missing concerning the high order Kerr non-linearities deduced from our experimental data published in [Opt. Express 17, 13429-13434 (2009)]. Here, we rectify this omission by making explicit the distinction between cross-Kerr and Kerr effects, and by extrapolating the value of the nonlinear refractive index for the last effect. Since the occurrence of sign inversion in the Kerr effect is not affected, the overall report in [Opt. Express 17, 13429-13434] remains valid.
General approach to spatiotemporal modulational instability processes
2011
International audience; In this article, we derive the general exact solution of the modulation instability gain. The solution described here is valid for 1-D, 2-D, and 3-D cases considering any temporal response function of the medium and with possible higher order Kerr nonlinearities. In particular, we show that the gain induced by modulation instability is initial condition dependent, while the usual calculations do not lead to such a dependence. Applications for current and high-interest nonlinear propagation problems, such as 1-D optical fiber propagation with delayed Raman response and 2-D filamentation in gases, are investigated in detail. More specifically, we demonstrate that the 2-D …