Sidelobe apodization in optical pulse compression reflectometry for fiber optic distributed acoustic sensing.

We demonstrate a technique to reduce the sidelobes in optical pulse compression reflectometry for distributed acoustic sensing. The technique is based on using a Gaussian probe pulse with linear frequency modulation. This is shown to improve the sidelobe suppression by 13 dB compared to the use of square pulses without any significant penalty in terms of spatial resolution.

Brillouin optical time-domain analysis sensor with pump pulse amplification.

We demonstrate a simple technique to provide conventional Brillouin optical time-domain analysis sensors with mitigation for pump pulse attenuation. The technique is based on operating the sensor in loss configuration so that energy is transferred from the probe wave to the pump pulse that becomes amplified as it counter-propagates with the probe wave. Furthermore, the optical frequency of the probe wave is modulated along the fiber so that the pump pulse experiences a flat total gain spectrum that equally amplifies all the spectral components of the pulse, hence, preventing distortion.

Comparative analysis of renal function after treatment of infrarenal abdominal aortic aneurysms with a suprarenal fixation device as opposed to open surgery.

We analyzed the repercussions on renal function between suprarenal endograft fixation and open surgery in the treatment of infrarenal abdominal aortic aneurysms (IAAAs) and determined the influential factors. Between 1999 and 2005, 59 IAAAs were treated with elective OS and 56 with SEF. The serum creatinine (Cr) level and its clearance were determined before the procedure, in the intensive care unit (ICU), on discharge, and after 1, 6, 12, and 24 months.

Oxidative damage to mitochondrial DNA and glutathione oxidation in apoptosis: studies in vivo and in vitro.

Free radicals may be involved in apoptosis although this is the subject of some controversy. Furthermore, the source of free radicals in apoptotic cells is not certain. The aim of this study was to elucidate the role of oxidative stress in the induction of apoptosis in serum-deprived fibroblast cultures and in weaned lactating mammary glands as in vitro and in vivo experimental models, respectively.

Regulation of tumour cell sensitivity to TNF-induced oxidative stress and cytotoxicity: role of glutathione.

Glutathione (GSH) and the rate of cellular proliferation determine tumour cell sensitivity to tumour necrosis factor (TNF). Buthionine sulphoximine (BSO), a selective inhibitor of GSH synthesis, inhibits tumour growth and increases recombinant human TNF (rhTNF)-alpha cytoxicity in vitro. Administration of sublethal doses of rhTNF-alpha to Ehrlich ascites-tumour (EAT)-bearing mice induces oxidative stress (as measured by increases in intracellular peroxide levels, O2.