The phase information obtained in photoacoustic experiments can be used to separate the signals originating from chemical species with overlapping absorption spectra. This approach was applied to quantify parts per million CO levels in propylene using quartz-enhanced photoacoustic spectroscopy and a quantum cascade laser as an excitation source. The experimental data were used to evaluate V –T ...

The interactions of actinomycin D (ACTD) with the oligonucleotides 5'-CAAAGCTTTG-3', 5'-CATGGCCATG-3' and 5'-TATGGCCATA-3' were investigated by means of acid-base titrations and mole-ratio and melting experiments monitored by molecular absorption and circular dichroism (CD) spectroscopies. For each experiment, CD and molecular absorption spectra were recorded at each point in the experiment, an...

Inhalation is now increasingly used as a route of drug administration, both small- and high‑molecular‑weight substances, although the scientific understanding of the mechanisms of their absorption is rather limited. The present review summarizes the mechanisms of absorption of higher‑molecular substances through the pulmonary epithelium with the aim to draw attention to this issue.

Our current understanding of iron absorption under normal conditions is presented, together with an overview of the clinical disorders of iron overload and the molecular processes that contribute to increased iron deposition in iron overload. Recently, a number of new genes involved in iron metabolism have been identified which is allowing the molecular mechanisms of iron absorption to be eluci...

The rapid and reliable identification of promoter regions is important when the number of genomes to be sequenced is increasing very speedily. Various methods have been developed but few methods investigate the effectiveness of sequence-based features in promoter prediction. This study proposes a knowledge acquisition method (named PromHD) based on if-then rules for promoter prediction in human...

Studies on the kinetics of gas-phase chemical reactions currently rely calculations or simulations and lack simple, fast, accurate direct measurement methods. We developed a tunable laser molecular absorption spectroscopy system to achieve measurements such by using wavelength modulated performed online diagnostics concentration, reaction temperature, pressure change during redox ozone with nit...

The photochemistry of diphenylphosphoryl azide was studied by femtosecond transient absorption spectroscopy, by chemical analysis of light-induced reaction products, and by RI-CC2/TZVP and TD-B3LYP/TZVP computational methods. Theoretical methods predicted two possible mechanisms for singlet diphenylphosphorylnitrene formation from the photoexcited phosphoryl azide. (i) Energy transfer from the ...

PURPOSE The structures of the ocular anterior segment responsible for aqueous humor secretion and absorption have been well characterized in mammals. However, the underlying molecular and cellular mechanisms that regulate aqueous humor flow have remained elusive. Experimental analysis in Danio rerio, the zebrafish, is providing mechanistic insights into many cellular processes relevant to norma...

Structural changes in water molecules are related to physiological, anatomical and pathological properties of tissues. Near infrared (NIR) optical absorption methods are sensitive to water; however, detailed characterization of water in thick tissues is difficult to achieve because subtle spectral shifts can be obscured by multiple light scattering. In the NIR, a water absorption peak is observ...