Comparison of metabolic adaptations between endurance- and sprint-trained athletes after an exhaustive exercise in two different calf muscles using a multi-slice P-MR spectroscopic sequence.

Measurements of exercise-induced metabolic changes, such as oxygen consumption, carbon dioxide exhalation or lactate concentration, are important indicators for assessing the current performance level of athletes in training science. With exercise-limiting metabolic processes occurring in loaded muscles, P-MRS represents a particularly powerful modality to identify and analyze corresponding training-induced alterations. Against this background, the current study aimed to analyze metabolic adaptations after an exhaustive exercise in two calf muscles (m.

The pH heterogeneity in human calf muscle during neuromuscular electrical stimulation.

Purpose: The aim of the study was to examine pH heterogeneity during fatigue induced by neuromuscular electrical stimulation (NMES) using phosphorus magnetic resonance spectroscopy ( P-MRS). It is hypothesized that three pH components would occur in the P-MRS during fatigue, representing three fiber types.

Methods: The medial gastrocnemius of eight subjects was stimulated within a 3-Tesla whole body MRI scanner.

Rapid multiplexed immunoassay for simultaneous serodiagnosis of HIV-1 and coinfections.

Diagnosis of opportunistic infections in HIV-infected individuals remains a major public health challenge, particularly in resource-limited settings. Here, we describe a rapid diagnostic system that delivers a panel of serologic immunoassay results using a single drop of blood, serum, or plasma. The system consists of disposable cartridges and a simple reader instrument, based on an innovative implementation of planar waveguide imaging technology.

Cavity-ringdown molecular spectroscopy based on an optical frequency comb at 1.45-1.65 microm.

Optical frequency comb-based cavity-ringdown spectroscopy has recently enabled high-sensitivity absorption detection of molecules over a broad spectral range. We demonstrate an improved system based on a mode-locked erbium-doped fiber laser source centered at 1.5 microm, resulting in a spectrometer that is inexpensive, simple, and robust.

Output coupling methods for cavity-based high-harmonic generation.

We have investigated the coupling efficiency and cavity loss associated with a ring cavity that has a hole in one of the focusing mirrors. The aperture provides a means through which intracavity high-harmonic generation can be coupled from the cavity. By studying different cavity geometries and input modes we have found that the integration of phase-plates on the focusing mirrors provides the best performance in terms of input coupling efficiency, cavity loss, and output-coupling of the generated high harmonic light.

Broadband cavity ringdown spectroscopy for sensitive and rapid molecular detection.

We demonstrate highly efficient cavity ringdown spectroscopy in which a broad-bandwidth optical frequency comb is coherently coupled to a high-finesse optical cavity that acts as the sample chamber. 125,000 optical comb components, each coupled into a specific longitudinal cavity mode, undergo ringdown decays when the cavity input is shut off. Sensitive intracavity absorption information is simultaneously available across 100 nanometers in the visible and near-infrared spectral regions.

Phase-coherent frequency combs in the vacuum ultraviolet via high-harmonic generation inside a femtosecond enhancement cavity.

We demonstrate the generation of phase-coherent frequency combs in the vacuum utraviolet spectral region. The output from a mode-locked laser is stabilized to a femtosecond enhancement cavity with a gas jet at the intracavity focus. The resulting high-peak power of the intracavity pulse enables efficient high-harmonic generation by utilizing the full repetition rate of the laser.