Search results for "DWI"
showing 10 items of 529 documents
Design of an integrated low-noise, low-power charge sensitive preamplifier for γ and particle spectroscopy with solid state detectors
2014
The design of an integrated charge-sensitive preamplifier suitable for γ-ray spectroscopy is presented. It is fully integrated, except for the feedback resistor, and can drive directly a 50Ω cable with its low impedance output stage. It is designed in AMS 0.35µm technology and its small dimensions and low power consumption (10 mW) are optimized for multi-channel applications. It works both with germanium and silicon detectors for a large range of values of electrode and feedback capacitances. Its wide bandwidth ensures a risetime of 10 ns or less in most configurations. This characteristic makes the preamplifier suitable not only for high resolution spectroscopy but also for pulse-shape ana…
Ultra-broadband terahertz time domain spectroscopy by Solid State Biased Coherent Detection
2017
The spectral fingerprint of ibuprofen within the THz frequency window has been retrieved through an ultra-broadband THz Time Domain Spectrometry set-up. The latter implements the Solid State Biased Coherent Detection scheme, based on a compact CMOS-compatible integrated device. Such a technique shows unprecedented advantages in term of bandwidth (greater than 10 THz) over other solid state methods like electro-optic sampling.
Spatio-temporal control of ultra-short pulses by using diffractive optical elements
2012
Diffractive optical elements (DOEs) have shown their applicability to control the spatio-temporal characteristics of ultra-short laser pulses. DOEs can provide high efficiency, compactness, very low material dispersion and, when implemented with spatial light modulators, real-time pulse engineering. In this communication, we report management of temporal and spectral profiles of ultra-short pulses by means of a quasi-direct space-to-time (QDST) pulse shaper. Moreover, we present spatio-temporal control, including dispersion compensation, by DOEs, and applications for activating nonlinear processes. On the other hand, we have achieved complete spatial control of ultra-short pulses, overcomin…
Space variant vision and pipelined architecture for time to impact computation
2002
Image analysis is one of the most interesting ways for a mobile vehicle to understand its environment. One of the tasks of an autonomous vehicle is to get accurate information of what it has in front, to avoid collision or find a way to a target. This task requires real-time restrictions depending on the vehicle speed and external object movement. The use of normal cameras, with homogeneous (squared) pixel distribution, for real-time image processing, usually requires high performance computing and high image rates. A different approach makes use of a CMOS space-variant camera that yields a high frame rate with low data bandwidth. The camera also performs the log-polar transform, simplifyin…
On the Advantages of Asynchronous Pixel Reading and Processing for High-Speed Motion Estimation
2008
Biological visual systems are becoming an interesting source for the improvement of artificial visual systems. A biologically inspired read-out and pixel processing strategy is presented. This read-out mechanism is based on Selective pixel Change-Driven (SCD) processing. Pixels are individually processed and read-out instead of the classical approach where the read-out and processing is based on complete frames. Changing pixels are read-out and processed at short time intervals. The simulated experiments show that the response delay using this strategy is several orders of magnitude lower than current cameras while still keeping the same, or even tighter, bandwidth requirements.
Prenatal Clinical Assessment of sFlt-1 (Soluble fms-like Tyrosine Kinase-1)/PlGF (Placental Growth Factor) Ratio as a Diagnostic Tool for Preeclampsi…
2013
Background: Aim of the study was a critical assessment of the clinical validity of the prenatal determination of sFlt-1/PlGF for preeclampsia (PE), pregnancy-induced hypertension (PIH), and proteinuria. Our analysis was based on a specificity of 95 % and a sensitivity of 82 % for the prediction of preeclampsia, as described by Elecsys (Roche). Methods: In this retrospective study the ratio of the prenatal antiangiogenic factor sFlt-1 (soluble fms-like tyrosine kinase-1) to the proangiogenic factor PIGF (placental growth factor) was analyzed using the electrochemiluminescence immunoassay of Elecsys (Roche Diagnostics, Mannheim, Germany) in 173 pregnant women. Sixty-three women with PE, 34 wo…
Survey of midwives' knowledge of caries prevention in perinatal care.
2014
Purpose To assess midwives' knowledge about oral health and early caries prevention during perinatal care for mothers and babies. Study design and methods A survey developed by the investigators was conducted among midwives to assess their knowledge about caries etiology, their attitude toward their role in early caries prevention, and prophylactic measures recommended during pregnancy, and after birth, for their babies. Self-administered questionnaires were sent to 180 midwives in hospitals and 323 midwives from a midwives' association in Hesse, Germany. Results Response rates were 46% (83/180) and 56% (181/323); a total of 264 questionnaires were evaluated. Most midwives were familiar wit…
RUOLO DEL COEFFICIENTE APPARENTE DI DIFFUSIONE (ADC) NELLO STUDIO DELLA PROSTATA IN RISONANZA MAGNETICA (RM)
2014
Materiali e Metodi: La nostra popolazione è costituita da 25 di età compresa tra 50 e 81 anni (media 63.95 +/- 9.54) sottoposti ad esame RM della prostata con apparecchiatura da 1.5 T mediante l'ausilio di bobina endorettale. Oltre al protocollo morfologico (T1w-T2w) , la valutazione spettroscopica e dinamica post-contrastografica, sono state acquisite sequenze DWI sul piano assiale con valori di b pari a 800/mm2. E' stato calcolato il valore di ADC in regioni di interesse poste in corrispondenza di aree di zona periferica (ZP) con aspetto normale ed aree che presentavano segnale ipointenso enne sequenze T2w e/o che mostravano restrizione della diffusione dell'acqua nelle sequenze DWI. All'…
1.3 µm GaInNAs optically-pumped vertical cavity semiconductor optical amplifier
2003
A GaInNAs/GaAs vertical cavity semiconductor optical amplifier (VCSOA) is reported. This is believed to be the first monolithic VCSOA operating at 1.3 mum. Under continuous-wave optical pumping in a singlemode fibre coupled format, gain figures of up to 17.7 dB were achieved. Amplification with 12 GHz bandwidth,was obtained at 12.8 dB peak gain.