2,334 research outputs found
A scientific repository to support the research and development of technologies related to quantitative electrocardiography: The Telemetric and Holter ECG Warehouse (THEW)
We implemented an ECG data-warehousing project to promote cross-fertilization of scientific
knowledge, resources and ideas that will advance the understanding of quantitative ECG and
cardiac safety. While other open ECG databases are available, our Telemetric and Holter ECG
Warehouse (THEW) proposes unique sets of continuous digital ECGs recorded in cardiac
patients, healthy individuals and individuals exposed to non-cardiac and cardiac drugs. In
this paper, we present briefly the content and the current research triggered by this initiative.
(Cardiol J 2010; 17, 4: 416-419
Optical Coherence Spectro-Tomography by all-Optical Depth-Wavelength analysis
Current spectroscopic optical coherence tomography (OCT) methods rely on a
posteriori numerical calculation. We present an alternative for accessing
optically the spectroscopic information in OCT, i.e. without any
post-processing, by using a grating based correlation and a wavelength
demultiplexing system. Conventional A-scan and spectrally resolved A-scan are
directly recorded on the image sensor. Furthermore, due to the grating based
system, no correlation scan is necessary. In the frame of this paper we present
the principle of the system as well as first experimental results
Stable mode-locked operation of a low repetition rate diode-pumped Nd : GdVO4 laser by combining quadratic polarisation switching and a semiconductor saturable absorber mirror
International audienceIn this paper, we present the mode-locked operation of an ultrarobustly stabilised Nd:GdVO4 laser with low repetition rate by combining quadratic polarisation switching and a semiconductor saturable absorber mirror (SESAM). In addition, similar experiment was also done with Nd:YVO4. For Nd:GdVO4, 16-ps pulses at 1063nm with a repetition rate of 3.95MHz have been obtained for a laser average output power of 1.4W. For Nd:YVO4, the performance was 2.5W of average power for15-ps pulses at 1064nm. Moreover, we demonstrate experimentally the advantage of combining these two passive mode locking techniques in terms of stability ranges. We show how the dual mode-locking technique is crucial to obtain a stable and long-term mode-locked regime in our case of a diode-pumped Nd:GdVO4 laser operating at low repetition rate and more generally how this dual mode-locking technique improves the stability range of the modelocked operation giving more flexibility on different parameter
Necrotizing vasculitis and exacerbation of psoriasis after granulocyte colony-stimulating factor for small cell lung carcinoma
Efficiency of dispersive wave generation in dual concentric core microstructured fiber
We describe the generation of powerful dispersive waves that are observed
when pumping a dual concentric core microstructured fiber by means of a
sub-nanosecond laser emitting at the wavelength of~1064 nm. The presence of
three zeros in the dispersion curve, their spectral separation from the pump
wavelength, and the complex dynamics of solitons originated by the pump pulse
break-up, all contribute to boost the amplitude of the dispersive wave on the
long-wavelength side of the pump. The measured conversion efficiency towards
the dispersive wave at 1548 nm is as high as 50%. Our experimental analysis of
the output spectra is completed by the acquisition of the time delays of the
different spectral components. Numerical simulations and an analytical
perturbative analysis identify the central wavelength of the red-shifted pump
solitons and the dispersion profile of the fiber as the key parameters for
determining the efficiency of the dispersive wave generation process.Comment: 11 pages, 12 figure
REFROIDISSEMENT MOLECULAIRE INDUIT PAR CHAMP ELECTRIQUE ; MISE EN EVIDENCE PAR SPECTROSCOPIE NON LINEAIRE CARS
National audienceNous avons montré qu'un refroidissement moléculaire pouvait être induit par un champ électrique statique appliqué à des molécules non polaires d'huile de paraffine. Cet effet a été mis en évidence grâce à une mesure de spectroscopie CARS (Coherent Anti-Stokes Raman Scattering). De manière complémentaire, l'exposition de molécules à un champ électrique permet de contrôler leur orientation et ainsi améliorer ou diminuer l'amplitude de leur signature vibrationnelle
Use and comparison of different internal ribosomal entry sites (IRES) in tricistronic retroviral vectors
BACKGROUND: Polycistronic retroviral vectors that contain several therapeutic genes linked via internal ribosome entry sites (IRES), provide new and effective tools for the co-expression of exogenous cDNAs in clinical gene therapy protocols. For example, tricistronic retroviral vectors could be used to genetically modify antigen presenting cells, enabling them to express different co-stimulatory molecules known to enhance tumor cell immunogenicity. RESULTS: We have constructed and compared different retroviral vectors containing two co-stimulatory molecules (CD70, CD80) and selectable marker genes linked to different IRES sequences (IRES from EMCV, c-myc, FGF-2 and HTLV-1). The tricistronic recombinant amphotropic viruses containing the IRES from EMCV, FGF-2 or HTLV-1 were equally efficient in inducing the expression of an exogenous gene in the transduced murine or human cells, without displaying any cell type specificity. The simultaneous presence of several IRESes on the same mRNA, however, can induce the differential expression of the various cistrons. Here we show that the IRESes of HTLV-1 and EMCV interfere with the translation induced by other IRESes in mouse melanoma cells. The IRES from FGF-2 did however induce the expression of exogenous cDNA in human melanoma cells without any positive or negative regulation from the other IRESs present within the vectors. Tumor cells that were genetically modified with the tricistronic retroviral vectors, were able to induce an in vivo anti-tumor immune response in murine models. CONCLUSION: Translation of the exogenous gene is directed by the IRES and its high level of expression not only depends on the type of cell that is transduced but also on the presence of other genetic elements within the vector
Improving the precision of QT measurements
Background: Accurate and precise QT interval measurement is very important for both
regulatory and drug developmental decision making. These measurements are often made
using a manual or semi-automated technique, and the associated variability necessitates
sample sizes of around 50 to 70 subjects in thorough QT/QTc studies. The purpose of this
study was to compare the reproducibility and precision of a semi-automated (SA) method and
a high-precision (HPQT) technique for ECG extraction and QT interval measurement on two
thorough QT/QTc (TQT) studies conducted in compliance with ICH E14.
Methods: Data from 35 healthy subjects from two different crossover TQT studies on treatment
with placebo and moxifloxacin was analyzed. Both methods examined the RR and QT
intervals measured in lead II or the lead with the highest quality T-wave on a single beat basis
using the QT algorithm included in the COMPAS software package. ECGs were measured at
a protocol-specific timepoint.
Results: The effect of moxifloxacin on the QTc interval was highly reproducible in the two
studies, and assay sensitivity was met with both methods. Pairwise comparison of QTcF
values between methods demonstrated high agreement with no bias, small mean differences
(below 1.5 ms) and narrow limits of agreement. HPQT improved the precision of the QTc
measurement by 31% in Study I (standard deviation of DQTcF: SA 8.9 ms; HPQT 6.3 ms)
and by 15% in Study II (SD: SA 9.7 ms; HPQT 8.3 ms).
Conclusions: The HPQT QT measurement technique detected the effect induced by
moxifloxacin with the same accuracy as SA techniques, and with clearly improved precision.
More precise QTc measurement has important implications in terms of lowering the likelihood
of false positive results and/or reducing the sample size in TQT studies, as well as improving
the utility of QT assessment in early clinical development. (Cardiol J 2011; 18, 4: 401–410
Bragg-Scattering conversion at telecom wavelengths towards the photon counting regime
9openopenKatarzyna Krupa; Alessandro Tonello; Victor Kozlov; Vincent
Couderc; Philippe Di Bin; Stefan Wabnitz; Alain Barthelemy;
Laurent Labonte; Sebastien TanzilliKatarzyna, Krupa; Alessandro, Tonello; Kozlov, Victor; Vincent, Couderc; Philippe Di, Bin; Wabnitz, Stefan; Alain, Barthelemy; Laurent, Labonte; Sebastien, Tanzill
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