Type I collagen is a major component of the extracellular matrix as well as many tissue engineered models. To understand changes in collagen related models over time, it is important to evaluate collagen dynamics with noninvasive techniques. Fluorescence spectroscopy provides a method to noninvasively measure endogenous collagen fluorescence. Additionally, second harmonic generation (SHG) imagi...

Based on a scanning near-field optical microscope (SNOM) we present measurements on the optical interaction of a single molecule and a single gold nanoparticle. The phenomena of field enhancement, emission quenching and fluorescence enhancement are studied with outstanding control over all key parameters. We have attached a single gold nanoparticle to the extremity of a pulled glass fiber tip a...

We present an in-depth analysis of molecular excitation in 11 H2-bright planetary and protoplanetary nebulae (PN and PPN). From newly acquired K-band observations, we extract a number of spectra at positions across each source. H2 line intensities are plotted on ‘column density ratio’ diagrams so that we may examine the excitation in and across each region. To achieve this, we combine the shock...

This investigation concerns the initial chemical reactions that affect the ionization of matrixes in matrix-assisted laser desorption/ionization (MALDI). The study focuses on the relaxations of photon energy that occur on a comparable time scale to that of ionization, in which the available laser energy is shared and the ionization condition is changed. The relaxations include fluorescence, fra...

This study assesses one possible cause of inter-patient variation in fluorescence spectroscopy of the cervix: the menstrual cycle. Ten patients with no history of an abnormal Pap smear were seen daily throughout 30 consecutive days of their cycle. Fluorescence excitation-emission matrices were measured from three cervical sites on each patient. Principal component analysis was used to determine...

Anammox is a cost-effective process to treat nitrogenous wastewater. In this work, excitation-emission matrix (EEM) fluorescence spectroscopy was used to characterize the intracellular and extracellular substances of anammox sludge during reactor operation of 276 days. Four main fluorophores were identified from the intracellular substances. Two main protein-like fluorophores were identified fr...

Attempts to access antibiotics by capturing biosynthetic genes and pathways directly from environmental DNA, which is overwhelmingly derived from uncultured bacteria, have revealed a large and previously unknown family of N-acyl amino acid synthases (NASs). The structure of the NAS FeeM reveals structural similarity to the GCN5-related N-acyl transferases and acylhomoserine lactone synthases. T...

Confocal fluorescence correlation spectroscopy as a time-averaging fluctuation analysis combining maximum sensitivity with high statistical confidence has proved to be a very versatile and powerful tool for detection and temporal investigation of biomolecules at ultralow concentrations on surfaces, in solutions, and in living cells. To probe the interaction of different molecular species for a ...

A new lead fluoroborate glass (PbO-PbF2-B2O3) doped with ytterbium (Yb:PbFB) is presented. Samples with different concentrations of Yb3+ were produced and had their emission cross-sections, fluorescence lifetimes and minimum pump intensities determined. They have high refractive index of 2.2 and a density of 4.4 g/cm3. For a doping level of 1.153x1020 ions/cm3, the fluorescence lifetime, after ...

The influence of the host matrix on the spectroscopic and laser properties of Nd(3+) in a K-Ba-Al phosphate glass has been investigated as a function of rare-earth concentration. Site-selective time resolved laser spectroscopy and stimulated emission experiments under selective wavelength laser pumping show the existence of a very complex crystal field site distribution of Nd(3+) ions in this g...