Based on IR absorbance spectra of healthy and malignant breast [1] and blood cells [2] found in literature we investigated the possibility of disease stage cell discrimination by comparing only a few absorbance peaks. This way no expensive FTIR spectroscope or time consuming expensive staining/labeling steps are required. Absorbance differences between healthy and malignant cells at wavelengths...

Our current understanding of the spectral sensitivities of the mysticete whale rod-based visual pigments is based on two species, the gray whale (Eschrichtius robustus) and the humpback whale (Megaptera novaeangliae) possessing absorbance maxima determined from difference spectra to be 492 and 497 nm, respectively. These absorbance maxima values are blueshifted relative to those from typical te...

Protein-chromophore interactions in photoreceptors often shift the chromophore absorbance maximum to a biologically relevant spectral region. A fundamental question regarding such spectral tuning effects is how the electronic ground state S(0) and excited state S(1) are modified by the protein. It is widely assumed that changes in energy gap between S(0) and S(1) are the main factor in biologic...

We characterize the leaf spectra of tree species of an Andean cloud forest in Venezuela, grouped according to position in canopy, subcanopy and understory. We measured leaf reflectance and transmittance spectra in the 400-750 nm range using a high-resolution spectrometer. Both signals were subtracted from unity to calculate the absorbance signal. Nine spectral variables were calculated for each...

Static FTIR light-induced difference spectra have been recorded for reaction centers from Rhodopseudomonas viridis in the following charge-separated states: P+QA(-)-PQA, P+QB(-)-PQB, I(-)-I, I-QA(-)-IQA, and I-QA(2-)-IQA. A comparison of the I(-)-I difference spectra with the I-QA(-)-IQA difference spectra reveals new bands which can be assigned to QA- vibrations; these vibrations are also obse...

Absorption spectra and light-induced absorbance changes of crystals from Rhodopseudomonas viridis reaction centers are recorded. A theoretical analysis of the absorption and circular dichroism spectra is presented, yielding a consistent picture of spectroscopic and structural information.

This study was conducted to investigate the effects of soil moisture content on reflectance spectra of sandy soils with different phosphorus (P) concentrations using UV-VIS-NIR reflectance spectroscopy. Sandy soils with average particle size of 250 μm were used. Investigations were conducted at 0, 12.5, 62.5, 175, 375, 750, and 1000 mg/kg phosphorus application rates. Three soil moisture conten...

Introduction: Forsteritic (Mg2SiO4, Fo) and fayalitic (Fe2SiO4, Fa) olivines exist as micron-sized dust grains in a variety of astrophysical and planetary environments. While an estimated ~ 95% of the silicate material that dominates the interstellar medium by mass is assumed to be amorphous [1], crystalline silicate dust particles are known to be present in dust disks around main-sequence star...