Biomedical subjects

F Brizuela

Publications and source records attributed to F Brizuela.

4 recordsLinked to original sources

PubMed2006

Sub-38 nm resolution tabletop microscopy with 13 nm wavelength laser light.

We have acquired images with a spatial resolution better than 38 nm by using a tabletop microscope that combines 13 nm wavelength light from a high-brightness tabletop laser and Fresnel zone plate optics. These results open a gateway to the development of compact and widely available extreme-ultraviolet imaging tools capable of inspecting samples in a variety of environments with a 15-20 nm spatial resolution and a picosecond time resolution.

Journal Article↗

PubMed2005

Capillary discharge-driven metal vapor plasma waveguides.

We report the generation of dense plasma waveguides containing a large concentration of silver ions by means of a fast (approximately 55 ns first half-cycle) microcapillary discharge. Concave plasma density profiles with axial electron density > 1 x 10(19) cm(-3) were measured from discharge ablation of 330 or 440 microm diameter Ag2S capillaries with 3-5 kA peak amplitude current pulses. The dynamic of this plasma waveguide was studied with interferometry, absorption measurements, and hydrodynamic model simulations. The results are relevant to the development of efficient longitudinally pumped metal vapor soft x-ray lasers, in particular those employing transient excitation of Ni-like ions. An approach to the design of a gain saturated wave-guided 13.9 nm laser in Ni-like Ag is discussed.

Journal Article↗

PubMed2005

Nanoimaging with a compact extreme-ultraviolet laser.

Images with a spatial resolution of 120-150 nm were obtained with 46.9 nm light from a compact capillary-discharge laser by use of the combination of a Sc-Si multilayer-coated Schwarzschild condenser and a free-standing imaging zone plate. The results are relevant to the development of compact extreme-ultraviolet laser-based imaging tools for nanoscience and nanotechnology.

Equipment Design↗

PubMedDate not supplied

[Hypertensive cardiopathy. Phonomechanocardiographic study and review of its physiopathological mechanisms].

Sixty four patients with essential hypertension were studied by phonocardiographic systolic time intervals. Prolongation of the pre-ejection period (PEP) at expense of the isovolume contraction time and of the true isovolume contraction time, which suggests myocardial contractile depression due to the increase in after-load. The significant increase, in rise of mean velocity of ventricular pressure suggests that the Anrep phemomena is used by the human heart as a compensatory mechanism in systemic hypertension. Ejection fraction in hypertensives was significantly lower (P less than 0.001) than that of normal controls, which indicates subclinical depression of ventricular function in the former. Myocardial hypertrophy can be considered as a compensatory mechanism which appears late in systemic hypertension and helps normalize ventricular performance and MVO2. It is clinically detected by an s-4 (registered by phonocardiographic tracings) and by an increase in the "A" index and the apexcardiogram (14.5 +/- 8%). The authors conclude that hypertensive heart disease can be identified early through the functional adaptations wich produce detrimental physiopathological reactions to the heart compensated initially by homeometric autorregulation and latter by myocardial hypertrophy.

Adult↗